| First Author | Li HD | Year | 2011 |
| Journal | PLoS One | Volume | 6 |
| Issue | 7 | Pages | e21678 |
| PubMed ID | 21747946 | Mgi Jnum | J:176073 |
| Mgi Id | MGI:5288282 | Doi | 10.1371/journal.pone.0021678 |
| Citation | Li HD, et al. (2011) Enhanced clathrin-dependent endocytosis in the absence of calnexin. PLoS One 6(7):e21678 |
| abstractText | BACKGROUND: Calnexin, together with calreticulin, constitute the calnexin/calreticulin cycle. Calnexin is a type I endoplasmic reticulum integral membrane protein and molecular chaperone responsible for the folding and quality control of newly-synthesized (glyco)proteins. The endoplasmic reticulum luminal domain of calnexin is responsible for lectin-like activity and interaction with nascent polypeptide chains. The role of the C-terminal, cytoplasmic portion of calnexin is not clear. METHODOLOGY/PRINCIPAL FINDINGS: Using yeast two hybrid screen and immunoprecipitation techniques, we showed that the Src homology 3-domain growth factor receptor-bound 2-like (Endophilin) interacting protein 1 (SGIP1), a neuronal specific regulator of endocytosis, forms complexes with the C-terminal cytoplasmic domain of calnexin. The calnexin cytoplasmic C-tail interacts with SGIP1 C-terminal domains containing the adaptor complexes medium subunit (Adap-Comp-Sub) region. Calnexin-deficient cells have enhanced clathrin-dependent endocytosis in neuronal cells and mouse neuronal system. This is reversed by expression of full length calnexin or calnexin C-tail. CONCLUSIONS/SIGNIFICANCE: We show that the effects of SGIP1 and calnexin C-tail on clathrin-dependent endocytosis are due to modulation of the internalization of the receptor-ligand complexes. Enhanced clathrin-dependent endocytosis in the absence of calnexin may contribute to the neurological phenotype of calnexin-deficient mice. |
