An 85-kD cytosolic complex ( @entity10407 (cplx)), consisting of a 62-kD phosphoprotein ( @entity10407 ) and a 25-kD GTPase, has been shown to be essential for the cell-free reconstitution of polymeric IgA receptor (pIgA-R)-containing exocytic transport vesicle formation from the TGN (Jones, S.M., J.R. Crosby, J. Salamero, and K.E. Howell. 1993. J. Cell Biol. 122:775-788). Here the @entity10407 (cplx) is identified as a regulatory subunit of a novel @entity4357 3-kinase (PI3-kinase). This @entity10407 (cplx)-associated PI3-kinase activity is stimulated by activation of the @entity10407 (cplx)-associated GTPase, and is specific for @entity4357 (PI) as substrate, and is sensitive to @entity2307 at micromolar concentrations. The direct role of this @entity10407 (cplx)-associated PI3-kinase activity in TGN-derived vesicle formation is indicated by the finding that both lipid kinase activity and the formation of pIgA-R-containing exocytic vesicles from the TGN are inhibited by @entity2307 with similar dose-response curves and 50% inhibitory concentrations (3.5 microM). These findings indicate that @entity8736 ( @entity25571 ) is required for the formation of TGN-derived exocytic transport vesicles, and that the @entity10407 (cplx)-associated PI3-kinase and an activated GTPase are the essential molecules that drive production of this PI(3)P.

XXXX 3-kinase is required for the formation of constitutive transport vesicles from the TGN.

@entity25571 :: ('CHEBI:26034', 'Chemical') :: ['PI[3]P'] @entity8736 :: ('MESH:C055525', 'Chemical') :: ['phosphatidylinositol-3-phosphate'] @entity10407 :: ('23636', 'Gene') :: ['p62'] @entity2307 :: ('MESH:C009687', 'Chemical') :: ['wortmannin'] @entity4357 :: ('MESH:D010716', 'Chemical') :: ['phosphatidylinositol']
@entity4357 :: (MESH:D010716,Chemical) :: ['Phosphatidylinositol']
