Molecular Mechanism of Membrane Recruitment of Gga by Arf in Lysosomal Protein TransportShiba, T., Kawasaki, M., Takatsu, H., Nogi, T., Matsugaki, N., Igarashi, N., Suzuki, M., Kato, R., Nakayama, K., Wakatsuki, S.
(2003) Nat Struct Biol 10: 386-393
- PubMed: 12679809
- DOI: https://doi.org/10.1038/nsb920
- Primary Citation of Related Structures:
1J2J, 1O3X, 1O3Y
- PubMed Abstract:
GGAs are critical for trafficking soluble proteins from the trans-Golgi network (TGN) to endosomes/lysosomes through interactions with TGN-sorting receptors, ADP-ribosylation factor (ARF) and clathrin. ARF-GTP bound to TGN membranes recruits its effector GGA by binding to the GAT domain, thus facilitating recognition of GGA for cargo-loaded receptors. Here we report the X-ray crystal structures of the human GGA1-GAT domain and the complex between ARF1-GTP and the N-terminal region of the GAT domain. When unbound, the GAT domain forms an elongated bundle of three a-helices with a hydrophobic core. Structurally, this domain, combined with the preceding VHS domain, resembles CALM, an AP180 homolog involved in endocytosis. In the complex with ARF1-GTP, a helix-loop-helix of the N-terminal part of GGA1-GAT interacts with the switches 1 and 2 of ARF1 predominantly in a hydrophobic manner. These data reveal a molecular mechanism underlying membrane recruitment of adaptor proteins by ARF-GTP.
Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan.