Functional and physical interactions of the adaptor protein complex AP-4 with ADP-ribosylation factors (ARFs)

AUTOR(ES)

Boehm, Markus

FONTE

Oxford University Press

RESUMO

AP-4 is a member of the family of heterotetrameric adaptor protein (AP) complexes that mediate the sorting of integral membrane proteins in post-Golgi compartments. This complex consists of four subunits (ε, β4, µ4 and σ4) and localizes to the cytoplasmic face of the trans-Golgi network (TGN). Here, we show that the recruitment of endogenous AP-4 to the TGN in vivo is regulated by the small GTP-binding protein ARF1. In addition, we demonstrate a direct interaction of the ε and µ4 subunits of AP-4 with ARF1. ε binds only to ARF1·GTP and requires residues in the switch I and switch II regions of ARF1. In contrast, µ4 binds equally well to the GTP- and GDP-bound forms of ARF1 and is less dependent on switch I and switch II residues. These observations establish AP-4 as an ARF1 effector and suggest a novel mode of interaction between ARF1 and an AP complex involving both constitutive and regulated interactions.

Documentos Relacionados

• ADP-Ribosylation Factor 1 Transiently Activates High-Affinity Adaptor Protein Complex AP-1 Binding Sites On Golgi Membranes
• ADP-ribosylation factor is functionally and physically associated with the Golgi complex.
• Activation of rat brain phospholipase D by ADP-ribosylation factors 1,5, and 6: separation of ADP-ribosylation factor-dependent and oleate-dependent enzymes.
• Nonenzymic ADP-ribosylation of specific mitochondrial polypeptides.
• Differential interaction of ADP-ribosylation factors 1, 3, and 5 with rat brain Golgi membranes.