BIOINFORMATICS APPLICATIONS NOTE
Vol. 28 no. 14 2012, pages 1949–1950
Databases and ontologies
IRView: a database and viewer for protein interacting regions
Shigeo Fujimori1, Naoya Hirai1, Kazuyo Masuoka1, Tomohiro Oshikubo1,2, Tatsuhiro
Yamashita1,3, Takanori Washio1,4, Ayumu Saito5, Masao Nagasaki5, Satoru Miyano5and
1Division of Interactome Medical Sciences, Institute of Medical Science, The University of Tokyo, Tokyo 108-8039,
Japan,2Production Solution Business Unit, Production Solution Division.II, Solution Department I, Fujitsu Advanced
Engineering Ltd., Tokyo 163-1017, Japan,3BioIT Business Development Unit, Fujitsu Ltd., Chiba 261-8588, Japan,
4Bioinformatics Department, RIKEN GENESIS Co., Ltd. Yokohama 230-0045, Japan and5Human Genome Center,
Institute of Medical Science, The University of Tokyo, Tokyo 108-8039, Japan
Associate Editor: Jonathan Wren
Advance Access publication May 15, 2012
Summary: Protein–protein interactions (PPIs) are mediated through
specific regions on proteins. Some proteins have two or more protein
interacting regions (IRs) and some IRs are competitively used for
interactions with different proteins. IRView currently contains data
for 3417 IRs in human and mouse proteins. The data were obtained
from different sources and combined with annotated region data
from InterPro. Information on non-synonymous single nucleotide
polymorphism sites and variable regions owing to alternative mRNA
splicing is also included. The IRView web interface displays all IR
data, including user-uploaded data, on reference sequences so that
the positional relationship between IRs can be easily understood.
IRView should be useful for analyzing underlying relationships
between the proteins behind the PPI networks.
Availability: IRView is publicly available on the web at
Received on November 21, 2011; revised on March 24, 2012;
accepted on May 10, 2012
Protein–protein interactions (PPIs) and their networks play central
roles in governing cellular processes. Recently, much effort has
been put in to collecting binary interaction data (e.g. Rual et al.,
2005) to dissect PPI networks. These interaction data have been
BioGRID (Breitkreutz et al., 2008) and IntAct (Aranda et al., 2009)
are major molecular interaction databases of PPIs. These databases
primarily contain PPI data at the protein level, namely pairs of
reported large-scale experimental data on region- or domain-based
protein interactions determined by high-throughput methods in
human (Miyamoto-Sato et al., 2010) and in Caenorhabditis elegans
(Boxem et al., 2008). Usually, proteins interact with other proteins
through regions (the interacting regions, IRs) that are specific to
each interaction; therefore, simultaneous interactions with multiple
proteins are possible (Kim et al., 2006). Furthermore, some IRs
are competitively involved in interactions with different proteins.
∗To whom correspondence should be addressed.
To comprehend the complicated relations underlying PPIs in more
detail, further refined interaction data are required.
In this article, we describe IRView, a database and viewer
for IRs of proteins, which focuses on the regions required for
PPIs. IRView contains, as a primary data source, IRs that were
determined using the in vitro virus (IVV) method (human data:
Miyamoto-Sato et al., 2010; mouse data: Horisawa et al., 2004
and Miyamoto-Sato et al., 2005) and the yeast two-hybrid (Y2H)
method. DOMINO (Ceol et al., 2007) is a database of domain–
domain interactions that is similar in scope to IRView. DOMINO
stores data on IRs described in the scientific literature and applies
the existing domain/motif names from the InterPro (Hunter et al.,
2009) database to each of the IRs. The IR data in IRView
include InterPro domain/motif regions but are not restricted to the
InterPro annotations. Users can also compare IRs with variable sites
susceptible to non-synonymous single nucleotide polymorphisms
(nsSNPs) and variable regions arising from alternative mRNA
splicing. IRView also supports a viewer that allows users to compare
the positional relationships of IRs in protein reference sequences
and in 3D structures (when available). IRView should be useful for
investigating the hidden relationships between the proteins behind
protein interaction networks.
2CONTENTS AND FEATURES
The current version of IRView contains 3417 unique IRs as the
default IR data. The IR data correspond to 1901 genes and were
obtained using the IVV (human data: Miyamoto-Sato et al., 2010;
mouse data: Horisawa et al., 2004 and Miyamoto-Sato et al., 2005)
andY2H (Sugaya et al., 2007) methods. Over half the IR data (2629
IRs) were derived from the results obtained using the IVV method
(Miyamoto-Sato et al., 2010).Although the current data and sources
for IRView are limited, we plan to add our original, experimental
data and data extracted from the literature. The IR data can be
downloaded in the PSI-MITAB format (Kerrien et al., 2007) file.
the positional relationships of the IRs were retrieved from the
InterPro database (Hunter et al., 2009). Data on the nsSNPs that can
(Mendelsohn, 2004; Schuster-Bockler and Bateman, 2008) were
The IR and other functional region data
© The Author(s) 2012. Published by Oxford University Press.
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/
by-nc/3.0), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
S.Fujimori et al.
obtained from the dbSNP (Smigielski et al., 2000). Variable regions
derived from alternative mRNA splicing that may potentially affect
protein interactions (Resch et al., 2004) were defined based on
the results of pair-wise alignments between the various isoforms.
The 3D structure data were downloaded from the Protein Data
Bank. When 3D models of complexes were available, information
about the interacting amino acid residues on different peptide chains
(defined as amino acids that were within a distance <4.0Å of each
other) were also added to the IR data.
One of the main features of IRView is that all positional data
are standardized to positions in reference sequences. IRView uses
the NCBI RefSeq sequences as the reference protein sequences.
When different isoforms of a protein are recorded in the RefSeq
database, the longest sequence was selected as the representative
sequence (RS) and the others were treated as related sequences.
Standardization of the position data was achieved by pair-wise
alignments between the RS and the other related sequences using
users can easily capture the positional relationships between
independently annotated regions from different sources. Using
the standardized position data, IRView can provide information
about the positional relationships between the IRs in one protein
sequence that interact with different proteins. In addition, IRView
provides information on the positional relationships between IRs
and other annotated regions (e.g. InterPro regions). Whether or
not an IR overlaps with any other annotated region is indicated
by special icons that accompany each IR entry. Of the 3417 IRs
in the current version of IRView, 1492 IRs overlap with known
domain/motif regions, 521 IRs overlap with nsSNPs, 207 IRs
overlap with structured regions, 102 IRs overlap with variable
with other IRs.
Reference sequence-centered map
IRView supports searches by protein name, gene symbol, NCBI
also supports the use of field specifiers to limit the scope of searches.
Query results are returned as a list of RSs which correspond to
a ‘Region information’ page consisting of a number of sections:
a ‘Gene summary’ section for basal information on the RSs; a
‘Protein sequences and regions’ section which contains positional
information for the IRs and other annotated regions related to the
RS; and a ‘Custom regions’ section which allows users to compare
positional relationships between arbitral IRs (e.g. in-house data) and
the IRs in the database. The ‘Protein sequences and regions’section
is divided into several subsections: ‘Representative sequence’,
‘Related sequences’, ‘Structured regions’, ‘Domain/Motif regions’,
‘Variable regions’, ‘Non-synonymous SNPs’, ‘Interacting regions’
and ‘Contacting amino acids’. To make it easier to compare two
or more annotated regions (e.g. comparing variant regions with IRs
to infer the impact of alternative splicing), unnecessary subsections
DESCRIPTION OF THE IRVIEW INTERFACE
can be collapsed. Details of these subsections are described in the
Help page of IRView.
IRView also possesses a system for mapping specific regions to
3D structure(s) when the corresponding structure data are available.
Users can map regions of interest to the 3D structure individually or
simultaneously via the in-lined Jmol applet (http://www.jmol.org/)
on any Java-enabled web browser.
We thank Katsuya Hino for his support in constructing the database.
We also thank Dr Hiroshi Yanagawa for helpful discussions and
Funding: Grant-in-Aid for Scientific Research on Innovative
Areas ‘Integrative Systems Understanding of Cancer for Advanced
Diagnosis, Therapy and Prevention (No. 4201)’ (grant number
23134510) of The Ministry of Education, Culture, Sports, Science
and Technology, Japan (to S.F.); Female Researcher Science Grant
from Shiseido Co., Ltd (to E.M.-S.).
Conflict of Interest: none declared.
Aranda,B. et al. (2009) The IntAct molecular interaction database in 2010. Nucleic
Acids Res., 38, D525–D531.
Boxem,M. et al. (2008) A protein domain-based interactome network for C. elegans
early embryogenesis. Cell, 134, 534–545.
Breitkreutz,B.J. et al. (2008) The BioGRID Interaction Database: 2008 update. Nucleic
Acids Res., 36, D637–D640.
Ceol,A. et al. (2007) DOMINO: a database of domain-peptide interactions. Nucleic
Acids Res., 35, D557–D560.
Horisawa,K. et al. (2004) In vitro selection of Jun-associated proteins using mRNA
display. Nucleic Acids Res., 32, e169.
Res., 37, D211–D215.
Kerrien, S. et al. (2007) Broadening the horizon–level 2.5 of the HUPO-PSI format for
molecular interactions. BMC Biol., 5, 44.
Kim,P.M. et al. (2006) Relating three-dimensional structures to protein networks
provides evolutionary insights. Science, 314, 1938–1941.
Larkin,M.A. et al. (2007) Clustal W and Clustal X version 2.0. Bioinformatics, 23,
Mendelsohn,A.R. (2004) Interaction trap/two-hybrid system to identify loss-of-
interaction mutant proteins. Curr. Protoc. Mol. Biol., Chapter 20, Unit 20 28.
Miyamoto-Sato,E. et al. (2005) Cell-free cotranslation and selection using in vitro virus
Res., 15, 710–717.
for refining human transcription factor networks. PLoS ONE, 5, e9289.
Resch,A. et al. (2004) Assessing the impact of alternative splicing on domain
interactions in the human proteome. J. Proteome. Res., 3, 76–83.
Rual,J.F. et al. (2005) Towards a proteome-scale map of the human protein–protein
interaction network. Nature, 437, 1173–1178.
Schuster-Bockler,B. and Bateman,A. (2008) Protein interactions in human genetic
diseases. Genome Biol., 9, R9.
Smigielski,E.M. et al. (2000) dbSNP: a database of single nucleotide polymorphisms.
Nucleic Acids Res., 28, 352–355.
Sugaya,N. et al. (2007)An integrative in silico approach for discovering candidates for
drug-targetable protein–protein interactions in interactome data. BMC Pharmacol.,