Modelling complexity and redundancy in actin polymerization

The Ayscough lab has shown that actin polymerization in yeast (for example during endocytosis) is a precisely timed and orchestrated event, with different proteins recruited at predictable times and orders. Much of it relies on interactions between polyproline sequences and SH3 binding domains. At a molecular level this looks like a messy system, with multiple tandem repeats and many competing interactions. Las-17 has 6 polyproline repeats and interacts with SLA1 (3 SH3), actin (one polyproline binding site per monomer) and about 10 other SH3-containing proteins. There is affinity data for many of the interactions.