NetAlign: a web-based tool for comparison of protein interaction networks.

Area of Science:

• Bioinformatics
• Systems Biology
• Computational Biology

Background:

• Comparative analysis of protein interaction networks (PINs) is crucial for understanding evolutionary relationships and identifying conserved functional modules.
• Existing tools may not fully integrate network topology and sequence similarity for comprehensive cross-species PIN analysis.

Purpose of the Study:

• To introduce NetAlign, a web-based tool for comparative analysis of PINs.
• To identify conserved network substructures (CoNSs) by integrating interaction topology and sequence similarity.
• To demonstrate the utility of NetAlign in uncovering evolutionary conserved modules and reformulating network-based biological problems.

Main Methods:

• NetAlign employs a comparative approach combining protein interaction topology and sequence similarity.
• It identifies conserved network substructures (CoNSs) between query and target PINs.
• Genome-scale comparisons were performed between Escherichia coli and Helicobacter pylori, and between Saccharomyces cerevisiae and Caenorhabditis elegans.

Main Results:

• NetAlign successfully identified conserved network substructures (CoNSs) across different species.
• Many identified CoNSs corresponded to known protein complexes, validating the approach.
• Species-specific differences in CoNSs provided insights into protein-protein interaction (PPI) prediction and species divergence.

Conclusions:

• Cross-species PIN comparison using NetAlign is an effective method for discovering conserved biological modules.
• The NetAlign tool facilitates the identification of evolutionary conserved network organization.
• Network-based analysis of CoNSs offers novel perspectives on PPI prediction and understanding species divergence.