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canonical GAT domain found in target of Myb protein 1 (Tom1) Tom1 was originally identified by its induced expression by the v-Myb oncogene. It is predominantly present in the cytosol and can interact with clathrin, endofin, Toll-interacting protein (Tollip), and ubiquitinated proteins. It acts as a linker protein to regulate the ability of endofin to recruit clathrin onto the sorting endosome. Moreover, Tom1 functions as a negative regulator of IL-1beta and tumor necrosis factor (TNF)-alpha-induced signaling pathways. It also plays a role in the TLR2/4 signaling pathways. Tom1 contains an N-terminal VHS (Vps27p/Hrs/STAM)-domain, a GAT (GGA and TOM1) domain and a C-terminal clathrin-binding region, both of which are conserved in Golgi-localized gamma ear-containing Arf-binding proteins (GGAs). In contrast to GGAs, Tom1 binds to ubiquitin, ubiquitinated proteins, and Tollip through its GAT domain, but does not associate with Arf GTPases through its GAT domain nor with acidic cluster-dileucine sequences through its VHS domain. The canonical GAT domain is a monomeric three-helix bundle that binds ubiquitin.
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