Organization of cell-regulatory systems through modular-protein-interaction domains.

Cells are organized through the interactions of proteins with one another, and with phospholipids, nucleic acids and small molecules, suggesting a molecular recognition code for cell assembly. These interactions are mediated by a set of conserved protein interaction domains, which regulate the dynamic behaviour of the cell, and are used to build protein complexes and networks with emergent properties. Cell regulatory proteins have a modular architecture, which may have facilitated the evolution of new signalling pathways, and is exploited by pathogenic micro-organisms and chimeric oncoproteins to re-specify cellular function.