Revisiting Date and Party Hubs: Novel Approaches to Role Assignment in Protein Interaction Networks

TL;DR

This paper critically reevaluates the traditional classification of protein interaction hubs into 'date' and 'party' types, showing that the distinction is less meaningful and proposing a focus on interaction roles instead.

Contribution

The study demonstrates that the date/party hub classification is not robust and suggests a shift towards role-based analysis of protein interactions.

Findings

Few central hubs drive network connectivity.

Co-expression does not reliably distinguish hub types.

Interaction roles correlate with functional similarity.

Abstract

The idea of 'date' and 'party' hubs has been influential in the study of protein-protein interaction networks. Date hubs display low co-expression with their partners, whilst party hubs have high co-expression. It was proposed that party hubs are local coordinators whereas date hubs are global connectors. Here we show that the reported importance of date hubs to network connectivity can in fact be attributed to a tiny subset of them. Crucially, these few, extremely central, hubs do not display particularly low expression correlation, undermining the idea of a link between this quantity and hub function. The date/party distinction was originally motivated by an approximately bimodal distribution of hub co-expression; we show that this feature is not always robust to methodological changes. Additionally, topological properties of hubs do not in general correlate with co-expression. Thus, we suggest that a date/party dichotomy is not meaningful and it might be more useful to conceive of roles for protein-protein interactions rather than individual proteins. We find significant correlations between interaction centrality and the functional similarity of the interacting proteins.