Our lab is particularly interested in large-scale genomic and biomedical data analysis with machine learning and network-based methods for research problems in health-related and biological science. The two broad areas for my research are 1) phenome-genome association analysis and 2) cancer outcome prediction and biomarker identification. In the first area, we performed large-scale association analysis between all genes and the complete collection of phenotypes (phenome) by network-based machine learning methods. In the second area, we developed graph-based learning models and kernel methods to capture the structures in single-cell RNA sequencing data, high-dimensional gene (isoform) expressions and DNA copy number variations for improved cancer outcome prediction and robust biomarker identification. In addition, we also developed kernel methods for protein classification. Our current projects center around the following topics,
- Spatial and single-cell transcriptomics: Spatial transcriptomics technologies have enabled spatially-resolved RNA profiling of single cells with cell identities and localizations for understanding cells’ organizations and functions. Our group develops new machine learning methods for mining RNA profiles collected from single cells and their spatial locations.
Broadbent, Charles; Song, Tianci; Kuang, Rui
Deciphering High-order Structures in Spatial Transcriptomes with Graph-guided Tucker Decomposition Best Paper Journal Article
In: Bioinformatics (Supplement Issue of the Proceedings of 32nd International Conference on Intelligent Systems for Molecular Biology (ISMB))↩, vol. 40, no. Supplement_1, pp. i529-i538, 2024.
@article{GraphTucker,
title = {Deciphering High-order Structures in Spatial Transcriptomes with Graph-guided Tucker Decomposition},
author = {Charles Broadbent and Tianci Song and Rui Kuang},
url = {https://academic.oup.com/bioinformatics/article/40/Supplement_1/i529/7700901},
doi = {doi.org/10.1093/bioinformatics/btae245},
year = {2024},
date = {2024-07-12},
urldate = {2024-07-12},
journal = {Bioinformatics (Supplement Issue of the Proceedings of 32nd International Conference on Intelligent Systems for Molecular Biology (ISMB))↩},
volume = {40},
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pages = {i529-i538},
howpublished = {To appear In the Proceedings of International Conference on Intelligent Systems for Molecular Biology (ISMB) 2024},
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Song, Tianci; Broadbent, Charles; Kuang, Rui
GNTD: Reconstructing Spatial Transcriptomes with Graph-guided Neural Tensor Decomposition Informed by Spatial and Functional Relations Journal Article
In: Nature Communications, vol. 14, no. 8276, 2023.
@article{GNTD,
title = {GNTD: Reconstructing Spatial Transcriptomes with Graph-guided Neural Tensor Decomposition Informed by Spatial and Functional Relations},
author = {Tianci Song and Charles Broadbent and Rui Kuang},
url = {https://www.nature.com/articles/s41467-023-44017-0},
year = {2023},
date = {2023-04-01},
urldate = {2023-04-01},
journal = {Nature Communications},
volume = {14},
number = {8276},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Atkins, Thomas Karl; Song, Tianci; Kuang, Rui
FIST-nD: A tool for n-dimensional spatial transcriptomics data imputation via graph-regularized tensor completio Technical Report
2022.
@techreport{FIST_nD,
title = {FIST-nD: A tool for n-dimensional spatial transcriptomics data imputation via graph-regularized tensor completio},
author = {Thomas Karl Atkins and Tianci Song and Rui Kuang
},
url = {https://www.biorxiv.org/content/10.1101/2022.10.12.511928v1.article-metrics},
doi = {10.1101/2022.10.12.511928},
year = {2022},
date = {2022-10-16},
urldate = {2022-10-16},
keywords = {},
pubstate = {published},
tppubtype = {techreport}
}
Song, Tianci; Markham, Kathleen K.; Li, Zhuliu; Muller, Kristen E.; Greenham, Kathleen; Kuang, Rui
Detecting Spatially Co-expressed Gene Clusters with Functional Coherence by Graph-regularized Convolutional Neural Network Journal Article
In: Bioinformatics, vol. 38, no. 5, pp. 1344–1352, 2022.
@article{spatialGCNNb,
title = {Detecting Spatially Co-expressed Gene Clusters with Functional Coherence by Graph-regularized Convolutional Neural Network},
author = {Tianci Song and Kathleen K. Markham and Zhuliu Li and Kristen E. Muller and Kathleen Greenham and Rui Kuang},
url = {https://academic.oup.com/bioinformatics/article/38/5/1344/6448221},
year = {2022},
date = {2022-03-01},
urldate = {2021-11-30},
journal = {Bioinformatics},
volume = {38},
number = {5},
pages = {1344–1352},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Li, Zhuliu; Song, Tianci; Yong, Jeongsik; Kuang, Rui
Imputation of spatially-resolved transcriptomes by graph-regularized tensor completion Journal Article
In: PLoS computational biology, vol. 17, no. 4, pp. e1008218, 2021.
@article{li2021imputation,
title = {Imputation of spatially-resolved transcriptomes by graph-regularized tensor completion},
author = {Zhuliu Li and Tianci Song and Jeongsik Yong and Rui Kuang},
url = {https://journals.plos.org/ploscompbiol/article?id=10.1371/journal.pcbi.1008218},
year = {2021},
date = {2021-01-01},
journal = {PLoS computational biology},
volume = {17},
number = {4},
pages = {e1008218},
publisher = {Public Library of Science San Francisco, CA USA},
keywords = {},
pubstate = {published},
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- Cancer genomics: Development of graph-based learning algorithms, sequence alignment algorithms and association rule-mining algorithms for building predictive models and mining biomarkers of cancer phenotypes from microarray or sequencing transcriptome data, DNA copy number variations, SNPs and protein-protein interactions.
Sorry, no publications matched your criteria.
- Phenome-genome association analysis: Development of graph-based learning algorithms for analyzing disease and gene associations in a network context.
Broadbent, Charles; Song, Tianci; Kuang, Rui
Deciphering High-order Structures in Spatial Transcriptomes with Graph-guided Tucker Decomposition Best Paper Journal Article
In: Bioinformatics (Supplement Issue of the Proceedings of 32nd International Conference on Intelligent Systems for Molecular Biology (ISMB))↩, vol. 40, no. Supplement_1, pp. i529-i538, 2024.
@article{GraphTucker,
title = {Deciphering High-order Structures in Spatial Transcriptomes with Graph-guided Tucker Decomposition},
author = {Charles Broadbent and Tianci Song and Rui Kuang},
url = {https://academic.oup.com/bioinformatics/article/40/Supplement_1/i529/7700901},
doi = {doi.org/10.1093/bioinformatics/btae245},
year = {2024},
date = {2024-07-12},
urldate = {2024-07-12},
journal = {Bioinformatics (Supplement Issue of the Proceedings of 32nd International Conference on Intelligent Systems for Molecular Biology (ISMB))↩},
volume = {40},
number = {Supplement_1},
pages = {i529-i538},
howpublished = {To appear In the Proceedings of International Conference on Intelligent Systems for Molecular Biology (ISMB) 2024},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Li, Zhuliu; Petegrosso, Raphael; Smith, Shaden; Sterling, David; Karypis, George; Kuang, Rui
Scalable Label Propagation for Multi-relational Learning on the Tensor Product of Graphs Journal Article
In: IEEE Transactions on Knowledge and Data Engineering, 2021.
@article{li2021scalable,
title = {Scalable Label Propagation for Multi-relational Learning on the Tensor Product of Graphs},
author = {Zhuliu Li and Raphael Petegrosso and Shaden Smith and David Sterling and George Karypis and Rui Kuang},
url = {https://ieeexplore.ieee.org/document/9369895/},
year = {2021},
date = {2021-01-01},
urldate = {2021-01-01},
journal = {IEEE Transactions on Knowledge and Data Engineering},
publisher = {IEEE},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Petegrosso, Raphael; Song, Tianci; Kuang, Rui
Hierarchical Canonical Correlation Analysis Reveals Phenotype, Genotype, and Geoclimate Associations in Plants Journal Article
In: Plant Phenomics, vol. 2020, no. 1969142, 2020.
@article{Petegrosso2020,
title = {Hierarchical Canonical Correlation Analysis Reveals Phenotype, Genotype, and Geoclimate Associations in Plants},
author = {Raphael Petegrosso and Tianci Song and Rui Kuang},
url = {https://spj.sciencemag.org/plantphenomics/2020/1969142/cta/},
doi = {10.34133/2020/1969142},
year = {2020},
date = {2020-03-31},
journal = {Plant Phenomics},
volume = {2020},
number = {1969142},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Li, Zhuliu; Zhang, Wei; Huang, R Stephanie; Kuang, Rui
Learning a Low-rank Tensor of Pharmacogenomic Multi-relations from Biomedical Networks Proceedings
IEEE International Conference on Data Mining 2019.
@proceedings{GTCORP2019b,
title = {Learning a Low-rank Tensor of Pharmacogenomic Multi-relations from Biomedical Networks},
author = {Zhuliu Li and Wei Zhang and R Stephanie Huang and Rui Kuang},
url = {http://compbio.cs.umn.edu/08970888.pdf},
year = {2019},
date = {2019-08-31},
organization = {IEEE International Conference on Data Mining},
abstract = {Learning pharmacogenomic multi-relations among diseases, genes and chemicals from content-rich biomedical and biological networks can provide important guidance for drug discovery, drug repositioning and disease treatment. Most of the existing methods focus on imputing missing values in the diseasegene, disease-chemical and gene-chemical pairwise relations from the observed relations instead of being designed for learning high-order disease-gene-chemical multi-relations. To achieve the goal, we propose a general tensor-based optimization framework and a scalable Graph-Regularized Tensor Completion from Observed Pairwise Relations (GT-COPR) algorithm to infer the multi-relations among the entities across multiple networks in a low-rank tensor, based on manifold regularization with the graph Laplacian of a Cartesian, tensor or strong product of the networks, and consistencies between the collapsed tensors and the observed bipartite relations. Our theoretical analyses also prove the convergence and efficiency of GT-COPR. In the experiments, the tensor fiber-wise and slice-wise evaluations demonstrate the accuracy of GT-COPR for predicting the diseasegene-chemical associations across the large-scale protein-protein interactions network, chemical structural similarity network and phenotype-based human disease network; and the validation on Genomics of Drug Sensitivity in Cancer cell line dataset shows a potential clinical application of GT-COPR for learning diseasespecific chemical-gene interactions. Statistical enrichment analysis demonstrates that GT-COPR is also capable of producing both topologically and biologically relevant disease, gene and chemical components with high significance.
Source code: https://github.com/kuanglab/GT-COPR},
keywords = {},
pubstate = {published},
tppubtype = {proceedings}
}
Learning pharmacogenomic multi-relations among diseases, genes and chemicals from content-rich biomedical and biological networks can provide important guidance for drug discovery, drug repositioning and disease treatment. Most of the existing methods focus on imputing missing values in the diseasegene, disease-chemical and gene-chemical pairwise relations from the observed relations instead of being designed for learning high-order disease-gene-chemical multi-relations. To achieve the goal, we propose a general tensor-based optimization framework and a scalable Graph-Regularized Tensor Completion from Observed Pairwise Relations (GT-COPR) algorithm to infer the multi-relations among the entities across multiple networks in a low-rank tensor, based on manifold regularization with the graph Laplacian of a Cartesian, tensor or strong product of the networks, and consistencies between the collapsed tensors and the observed bipartite relations. Our theoretical analyses also prove the convergence and efficiency of GT-COPR. In the experiments, the tensor fiber-wise and slice-wise evaluations demonstrate the accuracy of GT-COPR for predicting the diseasegene-chemical associations across the large-scale protein-protein interactions network, chemical structural similarity network and phenotype-based human disease network; and the validation on Genomics of Drug Sensitivity in Cancer cell line dataset shows a potential clinical application of GT-COPR for learning diseasespecific chemical-gene interactions. Statistical enrichment analysis demonstrates that GT-COPR is also capable of producing both topologically and biologically relevant disease, gene and chemical components with high significance.
Source code: https://github.com/kuanglab/GT-COPRZhang, Wei; Chien, Jeremy; Yong, Jeongsik; Kuang, Rui
Network-based Machine Learning and Graph Theory Algorithms for Precision Oncology Journal Article
In: NPJ Precision Oncology, no. 25, 2017.
@article{networkreview2017,
title = {Network-based Machine Learning and Graph Theory Algorithms for Precision Oncology},
author = {Wei Zhang and Jeremy Chien and Jeongsik Yong and Rui Kuang},
url = {https://www.nature.com/articles/s41698-017-0029-7},
doi = {doi:10.1038/s41698-017-0029-7},
year = {2017},
date = {2017-08-08},
journal = {NPJ Precision Oncology},
number = {25},
abstract = {Network-based analytics plays an increasingly important role in precision oncology. Growing evidence in recent studies suggests that cancer can be better understood through mutated or dysregulated pathways or networks rather than individual mutations and that the efficacy of repositioned drugs can be inferred from disease modules in molecular networks. This article reviews network-based machine learning and graph theory algorithms for integrative analysis of personal genomic data and biomedical knowledge bases to identify tumor-specific molecular mechanisms, candidate targets and repositioned drugs for personalized treatment. The review focuses on the algorithmic design and mathematical formulation of these methods to facilitate applications and implementations of network-based analysis in the practice of precision oncology. We review the methods applied in three scenarios to integrate genomic data and network models in different analysis pipelines, and we examine three categories of network-based approaches for repositioning drugs in drug-disease-gene networks. In addition, we perform a comprehensive subnetwork/pathway analysis of mutations in 31 cancer genome projects in the Cancer Genome Atlas (TCGA) and present a detailed case study on ovarian cancer. Finally, we discuss interesting observations, potential pitfalls and future directions in network-based precision oncology.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Network-based analytics plays an increasingly important role in precision oncology. Growing evidence in recent studies suggests that cancer can be better understood through mutated or dysregulated pathways or networks rather than individual mutations and that the efficacy of repositioned drugs can be inferred from disease modules in molecular networks. This article reviews network-based machine learning and graph theory algorithms for integrative analysis of personal genomic data and biomedical knowledge bases to identify tumor-specific molecular mechanisms, candidate targets and repositioned drugs for personalized treatment. The review focuses on the algorithmic design and mathematical formulation of these methods to facilitate applications and implementations of network-based analysis in the practice of precision oncology. We review the methods applied in three scenarios to integrate genomic data and network models in different analysis pipelines, and we examine three categories of network-based approaches for repositioning drugs in drug-disease-gene networks. In addition, we perform a comprehensive subnetwork/pathway analysis of mutations in 31 cancer genome projects in the Cancer Genome Atlas (TCGA) and present a detailed case study on ovarian cancer. Finally, we discuss interesting observations, potential pitfalls and future directions in network-based precision oncology. - Protein remote homology detection: Development of string kernel algorithms and label propagation algorithms to infer the protein remote homologys and study their protein structures and functions.
Petegrosso, Raphael; Li, Zhuliu; Srour, Molly A.; Saad, Yousef; Zhang, Wei; Kuang, Rui
Scalable Remote Homology Detection and Fold Recognition in Massive Protein Networks Journal Article
In: PROTEINS: Structure, Function, and Bioinformatics, vol. 87, no. 6, pp. 478-491, 2019.
@article{scalable2019petegrosso,
title = {Scalable Remote Homology Detection and Fold Recognition in Massive Protein Networks},
author = {Raphael Petegrosso and Zhuliu Li and Molly A. Srour and Yousef Saad and Wei Zhang and Rui Kuang},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/prot.25669},
year = {2019},
date = {2019-01-31},
journal = {PROTEINS: Structure, Function, and Bioinformatics},
volume = {87},
number = {6},
pages = {478-491},
abstract = {The global connectivities in very large protein similarity networks contain traces of evolution among the proteins for detecting protein remote evolutionary relations or structural similarities. To investigate how well a protein network captures the evolutionary information, a key limitation is the intensive computation of pairwise sequence similarities needed to construct very large protein networks. In this paper, we introduce Label Propagation on Low-rank Kernel Approximation (LP-LOKA) for searching massively large protein networks. LP-LOKA propagates initial protein similarities in a low-rank graph by Nystrom approximation without computing all pairwise similarities. With scalable parallel implementations based on distributed-memory using message-passing interface and Apache-Hadoop/Spark on cloud, LP-LOKA can search protein networks with one million proteins or more. In the experiments on Swiss-Prot/ADDA/CASP data, LP-LOKA significantly improved protein ranking over the widely used HMM-HMM or profile-sequence alignment methods utilizing large protein networks. It was observed that the larger the protein similarity network, the better the performance, especially on relatively small protein superfamilies and folds. The results suggest that computing massively large protein network is necessary to meet the growing need of annotating proteins from newly sequenced species and LP-LOKA is both scalable and accurate for searching massively large protein networks.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The global connectivities in very large protein similarity networks contain traces of evolution among the proteins for detecting protein remote evolutionary relations or structural similarities. To investigate how well a protein network captures the evolutionary information, a key limitation is the intensive computation of pairwise sequence similarities needed to construct very large protein networks. In this paper, we introduce Label Propagation on Low-rank Kernel Approximation (LP-LOKA) for searching massively large protein networks. LP-LOKA propagates initial protein similarities in a low-rank graph by Nystrom approximation without computing all pairwise similarities. With scalable parallel implementations based on distributed-memory using message-passing interface and Apache-Hadoop/Spark on cloud, LP-LOKA can search protein networks with one million proteins or more. In the experiments on Swiss-Prot/ADDA/CASP data, LP-LOKA significantly improved protein ranking over the widely used HMM-HMM or profile-sequence alignment methods utilizing large protein networks. It was observed that the larger the protein similarity network, the better the performance, especially on relatively small protein superfamilies and folds. The results suggest that computing massively large protein network is necessary to meet the growing need of annotating proteins from newly sequenced species and LP-LOKA is both scalable and accurate for searching massively large protein networks.Min, Martin Renqiang; Kuang, Rui; Bonner, Anthony J; Zhang, Zhaolei
Learning Random-Walk Kernels for Protein Remote Homology Identification and Motif Discovery. Proceedings Article
In: SDM, pp. 133–144, SIAM 2009, ISBN: 978-0-89871-682-5.
@inproceedings{min2009learning,
title = {Learning Random-Walk Kernels for Protein Remote Homology Identification and Motif Discovery.},
author = {Martin Renqiang Min and Rui Kuang and Anthony J Bonner and Zhaolei Zhang},
url = {http://compbio.cs.umn.edu/wp-content/uploads/2017/10/12E97816119727952E12.pdf},
doi = {10.1137/1.9781611972795.12},
isbn = {978-0-89871-682-5},
year = {2009},
date = {2009-04-30},
booktitle = {SDM},
pages = {133--144},
organization = {SIAM},
abstract = {Random-walk based algorithms are good choices for solving many classification problems with limited labeled data and a large amount of unlabeled data. However, it is difficult to choose the optimal number of random steps, and the results are very sensitive to the parameter chosen. In this paper, we will discuss how to better identify protein remote homology than any other algorithm using a learned random-walk kernel based on a positive linear combination of random-walk kernels with different random steps, which leads to a convex combination of kernels. The resulting kernel has much better prediction performance than the state-of-the-art profile kernel for protein remote homology identification. On the SCOP benchmark dataset, the overall mean ROC50 score on 54 protein families we obtained using the new kernel is above 0.90, which has almost perfect prediction performance on most of the 54 families and has significant improvement over the best published result; moreover, our approach based on learned random-walk kernels can effectively identify meaningful protein sequence motifs that are responsible for discriminating the memberships of protein sequences' remote homology in SCOP.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Random-walk based algorithms are good choices for solving many classification problems with limited labeled data and a large amount of unlabeled data. However, it is difficult to choose the optimal number of random steps, and the results are very sensitive to the parameter chosen. In this paper, we will discuss how to better identify protein remote homology than any other algorithm using a learned random-walk kernel based on a positive linear combination of random-walk kernels with different random steps, which leads to a convex combination of kernels. The resulting kernel has much better prediction performance than the state-of-the-art profile kernel for protein remote homology identification. On the SCOP benchmark dataset, the overall mean ROC50 score on 54 protein families we obtained using the new kernel is above 0.90, which has almost perfect prediction performance on most of the 54 families and has significant improvement over the best published result; moreover, our approach based on learned random-walk kernels can effectively identify meaningful protein sequence motifs that are responsible for discriminating the memberships of protein sequences' remote homology in SCOP.Ngo, Thanh; Kuang, Rui
Partial profile alignment kernels for protein classification Proceedings Article
In: 2009 IEEE International Workshop on Genomic Signal Processing and Statistics, pp. 1–4, IEEE 2009, ISBN: 978-1-4244-4761-9.
@inproceedings{ngo2009partial,
title = {Partial profile alignment kernels for protein classification},
author = {Thanh Ngo and Rui Kuang},
url = {http://compbio.cs.umn.edu/wp-content/uploads/2017/10/05174328.pdf},
doi = {10.1109/GENSIPS.2009.5174328},
isbn = {978-1-4244-4761-9},
year = {2009},
date = {2009-01-01},
booktitle = {2009 IEEE International Workshop on Genomic Signal Processing and Statistics},
pages = {1--4},
organization = {IEEE},
abstract = {Remote homology detection and fold recognition are the central problems in protein classification. In real applications, kernel algorithms that are both accurate and efficient are required for classification of large databases. We explore a class of partial profile alignment kernels to be used with support vector machines (SVMs) for remote homology detection and fold recognition. While existing profile-based kernels use the whole profiles to determine the similarity between pairs of proteins, the partial profile alignment kernels are derived from part of the position specific scoring matrices (PSSMs) in the profiles for alignment. Specifically, at each position in the PSSM, only amino acids in the mutation neighborhood of the corresponding amino acid in the original protein sequence are considered for alignment to remove noise and improve computing efficiency. Our experiments on SCOP bench datasets show that the partial profile alignment kernels achieved overall better classification results for both fold recognition and remote homology detection than profile kernels and profile-alignment kernels. In addition, our algorithm using only a fraction of the profiles saves the cost of computing the kernels significantly, compared to the full-profile alignment methods.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Remote homology detection and fold recognition are the central problems in protein classification. In real applications, kernel algorithms that are both accurate and efficient are required for classification of large databases. We explore a class of partial profile alignment kernels to be used with support vector machines (SVMs) for remote homology detection and fold recognition. While existing profile-based kernels use the whole profiles to determine the similarity between pairs of proteins, the partial profile alignment kernels are derived from part of the position specific scoring matrices (PSSMs) in the profiles for alignment. Specifically, at each position in the PSSM, only amino acids in the mutation neighborhood of the corresponding amino acid in the original protein sequence are considered for alignment to remove noise and improve computing efficiency. Our experiments on SCOP bench datasets show that the partial profile alignment kernels achieved overall better classification results for both fold recognition and remote homology detection than profile kernels and profile-alignment kernels. In addition, our algorithm using only a fraction of the profiles saves the cost of computing the kernels significantly, compared to the full-profile alignment methods.Kuang, Rui; Gu, Jianying; Cai, Hong; Wang, Yufeng
Improved prediction of malaria degradomes by supervised learning with SVM and profile kernel Journal Article
In: Genetica, vol. 136, no. 1, pp. 189–209, 2008.
@article{kuang2009improved,
title = {Improved prediction of malaria degradomes by supervised learning with SVM and profile kernel},
author = {Rui Kuang and Jianying Gu and Hong Cai and Yufeng Wang},
url = {http://link.springer.com/article/10.1007/s10709-008-9336-9},
doi = {10.1007/s10709-008-9336-9},
year = {2008},
date = {2008-12-06},
journal = {Genetica},
volume = {136},
number = {1},
pages = {189--209},
publisher = {Springer},
abstract = {The spread of drug resistance through malaria parasite populations calls for the development of new therapeutic strategies. However, the seemingly promising genomics-driven target identification paradigm is hampered by the weak annotation coverage. To identify potentially important yet uncharacterized proteins, we apply support vector machines using profile kernels, a supervised discriminative machine learning technique for remote homology detection, as a complement to the traditional alignment based algorithms. In this study, we focus on the prediction of proteases, which have long been considered attractive drug targets because of their indispensable roles in parasite development and infection. Our analysis demonstrates that an abundant and complex repertoire is conserved in five Plasmodium parasite species. Several putative proteases may be important components in networks that mediate cellular processes, including hemoglobin digestion, invasion, trafficking, cell cycle fate, and signal transduction. This catalog of proteases provides a short list of targets for functional characterization and rational inhibitor design.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The spread of drug resistance through malaria parasite populations calls for the development of new therapeutic strategies. However, the seemingly promising genomics-driven target identification paradigm is hampered by the weak annotation coverage. To identify potentially important yet uncharacterized proteins, we apply support vector machines using profile kernels, a supervised discriminative machine learning technique for remote homology detection, as a complement to the traditional alignment based algorithms. In this study, we focus on the prediction of proteases, which have long been considered attractive drug targets because of their indispensable roles in parasite development and infection. Our analysis demonstrates that an abundant and complex repertoire is conserved in five Plasmodium parasite species. Several putative proteases may be important components in networks that mediate cellular processes, including hemoglobin digestion, invasion, trafficking, cell cycle fate, and signal transduction. This catalog of proteases provides a short list of targets for functional characterization and rational inhibitor design.Melvin, Iain; Ie, Eugene; Kuang, Rui; Weston, Jason; Noble, William Stafford; Leslie, Christina
SVM-Fold: a tool for discriminative multi-class protein fold and superfamily recognition Journal Article
In: BMC bioinformatics, vol. 8, no. 4, 2007.
@article{melvin2007svm,
title = {SVM-Fold: a tool for discriminative multi-class protein fold and superfamily recognition},
author = {Iain Melvin and Eugene Ie and Rui Kuang and Jason Weston and William Stafford Noble and Christina Leslie},
url = {http://bmcbioinformatics.biomedcentral.com/articles/10.1186/1471-2105-8-S4-S2},
doi = {10.1186/1471-2105-8-S4-S2},
year = {2007},
date = {2007-05-22},
journal = {BMC bioinformatics},
volume = {8},
number = {4},
publisher = {BioMed Central},
abstract = {Background
Predicting a protein's structural class from its amino acid sequence is a fundamental problem in computational biology. Much recent work has focused on developing new representations for protein sequences, called string kernels, for use with support vector machine (SVM) classifiers. However, while some of these approaches exhibit state-of-the-art performance at the binary protein classification problem, i.e. discriminating between a particular protein class and all other classes, few of these studies have addressed the real problem of multi-class superfamily or fold recognition. Moreover, there are only limited software tools and systems for SVM-based protein classification available to the bioinformatics community.
Results
We present a new multi-class SVM-based protein fold and superfamily recognition system and web server called SVM-Fold, which can be found at http://svm-fold.c2b2.columbia.edu. Our system uses an efficient implementation of a state-of-the-art string kernel for sequence profiles, called the profile kernel, where the underlying feature representation is a histogram of inexact matching k-mer frequencies. We also employ a novel machine learning approach to solve the difficult multi-class problem of classifying a sequence of amino acids into one of many known protein structural classes. Binary one-vs-the-rest SVM classifiers that are trained to recognize individual structural classes yield prediction scores that are not comparable, so that standard "one-vs-all" classification fails to perform well. Moreover, SVMs for classes at different levels of the protein structural hierarchy may make useful predictions, but one-vs-all does not try to combine these multiple predictions. To deal with these problems, our method learns relative weights between one-vs-the-rest classifiers and encodes information about the protein structural hierarchy for multi-class prediction. In large-scale benchmark results based on the SCOP database, our code weighting approach significantly improves on the standard one-vs-all method for both the superfamily and fold prediction in the remote homology setting and on the fold recognition problem. Moreover, our code weight learning algorithm strongly outperforms nearest-neighbor methods based on PSI-BLAST in terms of prediction accuracy on every structure classification problem we consider.
Conclusion
By combining state-of-the-art SVM kernel methods with a novel multi-class algorithm, the SVM-Fold system delivers efficient and accurate protein fold and superfamily recognition.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Background
Predicting a protein's structural class from its amino acid sequence is a fundamental problem in computational biology. Much recent work has focused on developing new representations for protein sequences, called string kernels, for use with support vector machine (SVM) classifiers. However, while some of these approaches exhibit state-of-the-art performance at the binary protein classification problem, i.e. discriminating between a particular protein class and all other classes, few of these studies have addressed the real problem of multi-class superfamily or fold recognition. Moreover, there are only limited software tools and systems for SVM-based protein classification available to the bioinformatics community.
Results
We present a new multi-class SVM-based protein fold and superfamily recognition system and web server called SVM-Fold, which can be found at http://svm-fold.c2b2.columbia.edu. Our system uses an efficient implementation of a state-of-the-art string kernel for sequence profiles, called the profile kernel, where the underlying feature representation is a histogram of inexact matching k-mer frequencies. We also employ a novel machine learning approach to solve the difficult multi-class problem of classifying a sequence of amino acids into one of many known protein structural classes. Binary one-vs-the-rest SVM classifiers that are trained to recognize individual structural classes yield prediction scores that are not comparable, so that standard "one-vs-all" classification fails to perform well. Moreover, SVMs for classes at different levels of the protein structural hierarchy may make useful predictions, but one-vs-all does not try to combine these multiple predictions. To deal with these problems, our method learns relative weights between one-vs-the-rest classifiers and encodes information about the protein structural hierarchy for multi-class prediction. In large-scale benchmark results based on the SCOP database, our code weighting approach significantly improves on the standard one-vs-all method for both the superfamily and fold prediction in the remote homology setting and on the fold recognition problem. Moreover, our code weight learning algorithm strongly outperforms nearest-neighbor methods based on PSI-BLAST in terms of prediction accuracy on every structure classification problem we consider.
Conclusion
By combining state-of-the-art SVM kernel methods with a novel multi-class algorithm, the SVM-Fold system delivers efficient and accurate protein fold and superfamily recognition.