SUMMARY PARAGRAPH for TSC11
TSC11 encodes an essential protein that is a subunit of the TOR complex 2 (TORC2) (2). TORC2 is involved in regulating actin cytoskeleton polarization during cell cycle progression, cell wall integrity, and nutrient receptor endocytosis (6, 7). In addition to Tsc11p, TORC2 contains Avo1p, Avo2p, Lst8p, Bit61p, Slm1p, Slm2p, and Tor2p (2, 8). Tsc11p binds to the N-terminal HEAT (Huntingtin, Elongation factor 3, regulatory subunit A of PP2A, TOR1) repeat region of Tor2p and this interaction is necessary to maintain the structural integrity of TORC2 (9). Tor2p is also able to phosphorylate sites on Tsc11p, but the autophosphorylation function of TORC2 is not essential to its integrity (9). A RasGEFN domain, found in exchange factors and activating proteins for Ras-like small GTPases, is present in Tsc11p (2).
TSC11, originally identified as a suppressor of a mutation in CSG2 (3), is conserved from yeast to man and is the homolog of the mammalian protein rictor/mAVO3 (10, 11). Mutants in pianissimo, the Dictyostelium discoideum homolog of Tsc11p, are defective in receptor/G protein-mediated activation of adenylate cyclase (12). TORC2 is also structurally conserved in higher eukaryotes and, like yeast TORC2, functions to regulate the actin cytoskeleton (2, 11).
Last updated: 2006-10-12