Schematic diagrams depict some key elements of two human Rab GTPase activating proteins (GAP): Akt substrate of 160 kDa (AS160 or TBC1D4) and TBC1D1 (7, 13, 23–25, 30). Each protein includes two phosphotyrosine binding (PTB) domains, a calmodulin binding domain (CBD) and a GAP domain. AS160 includes more Akt phosphomotifs than TBC1D1. TBC1D1 includes an adenosine monophosphate (AMP)-activated protein kinase (AMPK) phosphomotif between the PTB domains that is absent from AS160. For clarity, the list of phosphomotifs identified in the figure is incomplete. TBC1D indicates tre-2/USP6, BUB2, cdc16 domain.