G Protein Beta Subunit Like Protein (GbL)

MLST8; Pop3; GbetaL; MTOR Associated Protein,LST8 Homolog; Mammalian lethal with SEC13 protein 8; Target of rapamycin complex subunit LST8

SPN	G235
HGNC	24825
MGI	1929514
PubMed	11072084
UniProt	Q9BVC4

The predicted human GBL protein shares 96.6% amino acid identity with rat Gbl, which contains 7 WD40 repeats similar to those of G protein beta subunits. Immunoprecipitation of membrane and cytosolic fractions of transfected human embryonic kidney cells showed that rat Gbl was predominantly cytosolic.Loss-of-function experiments using small interfering RNA showed that, like MTOR and raptor, GBL participated in nutrient- and growth factor-mediated signaling to S6K1 (RPS6KB1), a downstream effector of MTOR, and in control of cell size. Binding of GBL to MTOR strongly stimulated MTOR kinase activity toward S6K1 and 4EBP1 (EIF4EPB1), and this effect was reversed by stable interaction of raptor with MTOR. Nutrients and rapamycin regulated the association of MTOR with raptor only in complexes that also contained GBL.

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