A multivalent PDZ-domain protein assembles signalling complexes in a G-protein-coupled cascade.
Tsunoda, Susan; Sierralta, Jimena; Sun, Yumei; Bodner, Ruth; Suzuki, Emiko; Becker, Ann; Socolich, Michael; Zuker, Charles S.
[Article]
Nature.
388(6639):243-249, July 17, 1997.
(Format: HTML)
How are signalling molecules organized into different pathways within the same cell? In Drosophila, the inaD gene encodes a protein consisting of five PDZ domains which serves as a scaffold to assemble different components of the phototransduction cascade, including the principal light-activated ion channels, the effector phospholipase C-beta and protein kinase C. Null inaD mutants have a dramatically reorganized subcellular distribution of signalling molecules, and a total loss of transduction complexes. Also, mutants defective in a single PDZ domain produce signalling complexes that lack the target protein and display corresponding defects in their physiology. A picture emerges of a highly organized unit of signalling, a 'transducisome', with PDZ domains functioning as key elements in the organization of transduction complexes in vivo.
(C) 1997 Macmillan Magazines Ltd.