Control of biochemical reactions through supramolecular RING domain self-assembly.
RING domains act in a variety of unrelated biochemical reactions, with many of these domains forming key parts of supramolecular assemblies in cells. Here, we observe that purified RINGs from a variety of functionally unrelated proteins, including promyelocytic leukemia protein, KAP-1TIF1beta, Z, Mel18, breast cancer susceptibility gene product 1 (BRCA1), and BRCA1-associated RING domain (BARD1), self-assemble into supramolecular structures in vitro that resemble those they form in cells. RING bodies form polyvalent binding surfaces and scaffold multiple partner proteins. Separation of RING bodies from monomers reveals that self-assembly controls and amplifies their specific activities in two unrelated biochemistries: reduction of 5' mRNA cap affinity of eIF4E by promyelocytic leukemia protein and Z, and E3 ubiquitin conjugation activity of BARD1:BRCA1. Functional significance of self-assembly is underscored by partial restoration of assembly and E3 activity of cancer predisposing BRCA1 mutant by forced oligomerization. RING self-assembly creates bodies that act structurally as polyvalent scaffolds, thermodynamically by amplifying activities of partner proteins, and catalytically by spatiotemporal coupling of enzymatic reactions. These studies reveal a general paradigm of how supramolecular structures may function in cells.
SciCrunch is a data sharing and display platform. Anyone can create a custom portal where they can select searchable subsets of hundreds of data sources, brand their web pages and create their community. SciCrunch will push data updates automatically to all portals on a weekly basis. User communities can also add their own data to scicrunch, however this is not currently a free service.