TY - JOUR T1 - Evolutionarily conserved network properties of intrinsically disordered proteins. JF - PLoS One Y1 - 2015 A1 - Rangarajan, Nivedita A1 - Kulkarni, Prakash A1 - Hannenhalli, Sridhar KW - Animals KW - Cluster Analysis KW - Databases, Protein KW - Drosophila KW - Drosophila Proteins KW - Evolution, Molecular KW - HUMANS KW - Intrinsically Disordered Proteins KW - Metabolic Networks and Pathways KW - Mice KW - Osmotic Pressure KW - Protein Interaction Maps KW - Saccharomyces cerevisiae KW - Saccharomyces cerevisiae Proteins AB -

BACKGROUND: Intrinsically disordered proteins (IDPs) lack a stable tertiary structure in isolation. Remarkably, however, a substantial portion of IDPs undergo disorder-to-order transitions upon binding to their cognate partners. Structural flexibility and binding plasticity enable IDPs to interact with a broad range of partners. However, the broader network properties that could provide additional insights into the functional role of IDPs are not known.

RESULTS: Here, we report the first comprehensive survey of network properties of IDP-induced sub-networks in multiple species from yeast to human. Our results show that IDPs exhibit greater-than-expected modularity and are connected to the rest of the protein interaction network (PIN) via proteins that exhibit the highest betweenness centrality and connect to fewer-than-expected IDP communities, suggesting that they form critical communication links from IDP modules to the rest of the PIN. Moreover, we found that IDPs are enriched at the top level of regulatory hierarchy.

CONCLUSION: Overall, our analyses reveal coherent and remarkably conserved IDP-centric network properties, namely, modularity in IDP-induced network and a layer of critical nodes connecting IDPs with the rest of the PIN.

VL - 10 CP - 5 M3 - 10.1371/journal.pone.0126729 ER - TY - Generic T1 - Quantitative measurement of allele-specific protein expression in a diploid yeast hybrid by LC-MS. Y1 - 2012 A1 - Khan, Zia A1 - Bloom, Joshua S A1 - Amini, Sasan A1 - Singh, Mona A1 - Perlman, David H A1 - Caudy, Amy A A1 - Kruglyak, Leonid KW - Alleles KW - Chromatography, Liquid KW - Fungal Proteins KW - Gene Expression Profiling KW - Gene Expression Regulation, Fungal KW - HUMANS KW - Mass Spectrometry KW - proteomics KW - Regression Analysis KW - Saccharomyces KW - Saccharomyces cerevisiae KW - Saccharomyces cerevisiae Proteins KW - Species Specificity AB -

Understanding the genetic basis of gene regulatory variation is a key goal of evolutionary and medical genetics. Regulatory variation can act in an allele-specific manner (cis-acting) or it can affect both alleles of a gene (trans-acting). Differential allele-specific expression (ASE), in which the expression of one allele differs from another in a diploid, implies the presence of cis-acting regulatory variation. While microarrays and high-throughput sequencing have enabled genome-wide measurements of transcriptional ASE, methods for measurement of protein ASE (pASE) have lagged far behind. We describe a flexible, accurate, and scalable strategy for measurement of pASE by liquid chromatography-coupled mass spectrometry (LC-MS). We apply this approach to a hybrid between the yeast species Saccharomyces cerevisiae and Saccharomyces bayanus. Our results provide the first analysis of the relative contribution of cis-acting and trans-acting regulatory differences to protein expression divergence between yeast species.

JA - Mol Syst Biol VL - 8 M3 - 10.1038/msb.2012.34 ER - TY - JOUR T1 - Measuring differential gene expression by short read sequencing: quantitative comparison to 2-channel gene expression microarrays. JF - BMC Genomics Y1 - 2009 A1 - Bloom, Joshua S A1 - Khan, Zia A1 - Kruglyak, Leonid A1 - Singh, Mona A1 - Caudy, Amy A KW - algorithms KW - DNA, Complementary KW - DNA, Fungal KW - Gene Expression Profiling KW - Oligonucleotide Array Sequence Analysis KW - Saccharomyces cerevisiae KW - sequence alignment KW - Sequence Analysis, DNA AB -

BACKGROUND: High-throughput cDNA synthesis and sequencing of poly(A)-enriched RNA is rapidly emerging as a technology competing to replace microarrays as a quantitative platform for measuring gene expression.

RESULTS: Consequently, we compared full length cDNA sequencing to 2-channel gene expression microarrays in the context of measuring differential gene expression. Because of its comparable cost to a gene expression microarray, our study focused on the data obtainable from a single lane of an Illumina 1 G sequencer. We compared sequencing data to a highly replicated microarray experiment profiling two divergent strains of S. cerevisiae.

CONCLUSION: Using a large number of quantitative PCR (qPCR) assays, more than previous studies, we found that neither technology is decisively better at measuring differential gene expression. Further, we report sequencing results from a diploid hybrid of two strains of S. cerevisiae that indicate full length cDNA sequencing can discover heterozygosity and measure quantitative allele-specific expression simultaneously.

VL - 10 M3 - 10.1186/1471-2164-10-221 ER - TY - JOUR T1 - MDP-1 is a new and distinct member of the haloacid dehalogenase family of aspartate-dependent phosphohydrolases JF - BiochemistryBiochemistry Y1 - 2001 A1 - J. Selengut KW - Amino Acid Motifs KW - Amino Acid Sequence KW - Animals KW - Aspartic Acid KW - Catalytic Domain KW - HUMANS KW - Hydrolases KW - Mice KW - Molecular Sequence Data KW - Multigene Family KW - Mutagenesis, Site-Directed KW - Phosphoprotein Phosphatases KW - Protein Structure, Tertiary KW - Protein Tyrosine Phosphatases KW - Rats KW - Saccharomyces cerevisiae KW - sequence alignment KW - Sequence Homology, Amino Acid AB - MDP-1 is a eukaryotic magnesium-dependent acid phosphatase with little sequence homology to previously characterized phosphatases. The presence of a conserved motif (Asp-X-Asp-X-Thr) in the N terminus of MDP-1 suggested a relationship to the haloacid dehalogenase (HAD) superfamily, which contains a number of magnesium-dependent acid phosphatases. These phosphatases utilize an aspartate nucleophile and contain a number of conserved active-site residues and hydrophobic patches, which can be plausibly aligned with conserved residues in MDP-1. Seven site-specific point mutants of MDP-1 were produced by modifying the catalytic aspartate, serine, and lysine residues to asparagine or glutamate, alanine, and arginine, respectively. The activity of these mutants confirms the assignment of MDP-1 as a member of the HAD superfamily. Detailed comparison of the sequence of the 15 MDP-1 sequences from various organisms with other HAD superfamily sequences suggests that MDP-1 is not closely related to any particular member of the superfamily. The crystal structures of several HAD family enzymes identify a domain proximal to the active site responsible for important interactions with low molecular weight substrates. The absence of this domain or any other that might perform the same function in MDP-1 suggests an "open" active site capable of interactions with large substrates such as proteins. This suggestion was experimentally confirmed by demonstration that MDP-1 is competent to catalyze the dephosphorylation of tyrosine-phosphorylated proteins. VL - 40 N1 - http://www.ncbi.nlm.nih.gov/pubmed/11601995?dopt=Abstract ER - TY - JOUR T1 - RNA processing. Sequences that signal where to splice. JF - Nature Y1 - 1983 A1 - Mount, S M KW - Base Sequence KW - RNA Splicing KW - Saccharomyces cerevisiae VL - 304 CP - 5924 ER -