Protein Domains

Binding Domain for the PC Motif

Science's STKE  07 Aug 2001:
Vol. 2001, Issue 94, pp. tw10
DOI: 10.1126/stke.2001.94.tw10

The guanine-nucleotide regulatory protein Cdc24p is one of the many signaling proteins that have an evolutionarily conserved sequence called the PC motif. However, the physiological significance of this 20-amino acid sequence had not been determined. Ito et al. report that the PC motif mediates protein-protein interactions by binding to a protein domain called PB1. The domain was identified in Bem1p, a scaffold protein involved in establishing cell polarity in budding yeast. This interaction was necessary for normal yeast budding to occur. The authors determined that a PB1-PC interaction also mediates interaction of p67phox and p40phox , two components of the mammalian NADPH oxidase system, as well as protein kinase C interaction with the adaptor protein ZIP. Hence, PB1-PC interactions may mediate a variety of functional protein-protein interactions. Terasawa et al. have also determined the structure and ligand-binding site of the PB1 domain of Bem1p by using NMR.

T. Ito, Y. Matsui, T. Ago, K. Ota, H. Sumimoto, Novel modular domain PB1 recognizes PC motif to mediate functional protein-protein interactions. EMBO J. 20, 3938-3946 (2001). [Abstract] [Full Text]

H. Terasawa, Y. Noda, T. Ito, H. Hatanaka, S. Ichikawa, K. Ogura, H. Sumimoto, F. Inagaki, Structure and ligand recognition of the PB1 domain: A novel protein module binding to the PC motif. EMBO J. 20, 3947-3956 (2001). [Abstract] [Full Text]