Triangle network motifs predict complexes by complementing high-error interactomes with structural information

<p>Abstract</p> <p>Background</p> <p>A lot of high-throughput studies produce protein-protein interaction networks (PPINs) with many errors and missing information. Even for genome-wide approaches, there is often a low overlap between PPINs produced by different studies...

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Main Authors: Labudde Dirk, Winter Christof, Andreopoulos Bill, Schroeder Michael
Format: Article
Language:English
Published: BMC 2009-06-01
Series:BMC Bioinformatics
Online Access:http://www.biomedcentral.com/1471-2105/10/196
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author Labudde Dirk
Winter Christof
Andreopoulos Bill
Schroeder Michael
author_facet Labudde Dirk
Winter Christof
Andreopoulos Bill
Schroeder Michael
author_sort Labudde Dirk
collection DOAJ
description <p>Abstract</p> <p>Background</p> <p>A lot of high-throughput studies produce protein-protein interaction networks (PPINs) with many errors and missing information. Even for genome-wide approaches, there is often a low overlap between PPINs produced by different studies. Second-level neighbors separated by two protein-protein interactions (PPIs) were previously used for predicting protein function and finding complexes in high-error PPINs. We retrieve second level neighbors in PPINs, and complement these with structural domain-domain interactions (SDDIs) representing binding evidence on proteins, forming PPI-SDDI-PPI triangles.</p> <p>Results</p> <p>We find low overlap between PPINs, SDDIs and known complexes, all well below 10%. We evaluate the overlap of PPI-SDDI-PPI triangles with known complexes from Munich Information center for Protein Sequences (MIPS). PPI-SDDI-PPI triangles have ~20 times higher overlap with MIPS complexes than using second-level neighbors in PPINs without SDDIs. The biological interpretation for triangles is that a SDDI causes two proteins to be observed with common interaction partners in high-throughput experiments. The relatively few SDDIs overlapping with PPINs are part of highly connected SDDI components, and are more likely to be detected in experimental studies. We demonstrate the utility of PPI-SDDI-PPI triangles by reconstructing myosin-actin processes in the nucleus, cytoplasm, and cytoskeleton, which were not obvious in the original PPIN. Using other complementary datatypes in place of SDDIs to form triangles, such as PubMed co-occurrences or threading information, results in a similar ability to find protein complexes.</p> <p>Conclusion</p> <p>Given high-error PPINs with missing information, triangles of mixed datatypes are a promising direction for finding protein complexes. Integrating PPINs with SDDIs improves finding complexes. Structural SDDIs partially explain the high functional similarity of second-level neighbors in PPINs. We estimate that relatively little structural information would be sufficient for finding complexes involving most of the proteins and interactions in a typical PPIN.</p>
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spelling doaj.art-24333bcae6a043cabe417db59882a5f22022-12-21T22:01:47ZengBMCBMC Bioinformatics1471-21052009-06-0110119610.1186/1471-2105-10-196Triangle network motifs predict complexes by complementing high-error interactomes with structural informationLabudde DirkWinter ChristofAndreopoulos BillSchroeder Michael<p>Abstract</p> <p>Background</p> <p>A lot of high-throughput studies produce protein-protein interaction networks (PPINs) with many errors and missing information. Even for genome-wide approaches, there is often a low overlap between PPINs produced by different studies. Second-level neighbors separated by two protein-protein interactions (PPIs) were previously used for predicting protein function and finding complexes in high-error PPINs. We retrieve second level neighbors in PPINs, and complement these with structural domain-domain interactions (SDDIs) representing binding evidence on proteins, forming PPI-SDDI-PPI triangles.</p> <p>Results</p> <p>We find low overlap between PPINs, SDDIs and known complexes, all well below 10%. We evaluate the overlap of PPI-SDDI-PPI triangles with known complexes from Munich Information center for Protein Sequences (MIPS). PPI-SDDI-PPI triangles have ~20 times higher overlap with MIPS complexes than using second-level neighbors in PPINs without SDDIs. The biological interpretation for triangles is that a SDDI causes two proteins to be observed with common interaction partners in high-throughput experiments. The relatively few SDDIs overlapping with PPINs are part of highly connected SDDI components, and are more likely to be detected in experimental studies. We demonstrate the utility of PPI-SDDI-PPI triangles by reconstructing myosin-actin processes in the nucleus, cytoplasm, and cytoskeleton, which were not obvious in the original PPIN. Using other complementary datatypes in place of SDDIs to form triangles, such as PubMed co-occurrences or threading information, results in a similar ability to find protein complexes.</p> <p>Conclusion</p> <p>Given high-error PPINs with missing information, triangles of mixed datatypes are a promising direction for finding protein complexes. Integrating PPINs with SDDIs improves finding complexes. Structural SDDIs partially explain the high functional similarity of second-level neighbors in PPINs. We estimate that relatively little structural information would be sufficient for finding complexes involving most of the proteins and interactions in a typical PPIN.</p>http://www.biomedcentral.com/1471-2105/10/196
spellingShingle Labudde Dirk
Winter Christof
Andreopoulos Bill
Schroeder Michael
Triangle network motifs predict complexes by complementing high-error interactomes with structural information
BMC Bioinformatics
title Triangle network motifs predict complexes by complementing high-error interactomes with structural information
title_full Triangle network motifs predict complexes by complementing high-error interactomes with structural information
title_fullStr Triangle network motifs predict complexes by complementing high-error interactomes with structural information
title_full_unstemmed Triangle network motifs predict complexes by complementing high-error interactomes with structural information
title_short Triangle network motifs predict complexes by complementing high-error interactomes with structural information
title_sort triangle network motifs predict complexes by complementing high error interactomes with structural information
url http://www.biomedcentral.com/1471-2105/10/196
work_keys_str_mv AT labuddedirk trianglenetworkmotifspredictcomplexesbycomplementinghigherrorinteractomeswithstructuralinformation
AT winterchristof trianglenetworkmotifspredictcomplexesbycomplementinghigherrorinteractomeswithstructuralinformation
AT andreopoulosbill trianglenetworkmotifspredictcomplexesbycomplementinghigherrorinteractomeswithstructuralinformation
AT schroedermichael trianglenetworkmotifspredictcomplexesbycomplementinghigherrorinteractomeswithstructuralinformation