Identification of a novel mono-leucine basolateral sorting motif within the cytoplasmic domain of amphiregulin.

摘要: Epithelial cells establish apical and basolateral (BL) membranes with distinct protein lipid compositions. To achieve this spatial asymmetry, the cell utilizes a variety of mechanisms for differential sorting, delivery retention surface proteins. The EGF receptor (EGFR) its ligand, amphiregulin (AREG), are transmembrane proteins delivered to BL membrane in polarized epithelial cells. Herein, we show that cytoplasmic domain AREG (ACD) contains dominant sorting information; replacement apically targeted nerve growth factor ACD redirects chimera surface. Using sequential truncations site-directed mutagenesis ACD, identify novel motif consisting single leucine C-terminal an acidic cluster (EEXXXL). In adaptor (AP)-1B-deficient cells, newly synthesized is initially as AP-1B-expressing However, these AP-1B-deficient recycling back compromised, leading appearance at These results recycling, but not delivery, AP-1B dependent.