| Primary Identifier | IPR028644 | Type | Family |
| Short Name | SNX9 |
| description | Sorting nexins are a large family of evolutionarily conserved phosphoinositide-binding proteins that have roles in cargo sorting through the endosomal netwrok []. Sorting nexins contain at least a PX domain (a phospholipid-binding motif). Some nexins contain a few additional domains. Proteins in the sorting nexin 9 subfamily includes SNX9, SNX18 and SNX33 []. They are characterised by the presence of an N-terminal SH3 domain (), a PX domain that is a phosphoinositide-binding module (), and a Bin/Amphiphysin/Rvs (BAR) domain at the C terminus, which allows membrane binding and bending. They are required for progression and completion of mitosis []. Sorting nexin 9 (SNX9) is a well-characterised member of this group; it is has been suggested to be involved in the endocytic process as an accessory factor []. SNX9 has binding sites for both clathrin and adaptor protein AP-2 in a low complexity region, and binds dynamin-2 (Dyn2) by its SH3 domain. SNX9 has its own membrane-binding activity, mediated by a carboxyl-terminal region containing the PX domain and the BAR domain []. Endogenous SNX9 partially co-localizes with AP-2 and Dyn2 at the plasma membrane, and over expression in K562 and HeLa cells of truncated versions of SNX9 inhibits the uptake of transferrin []. Moreover, SNX9 is required for efficient clathrin-mediated endocytosis, which suggests that it functions to regulate dynamin activity []. |
