ENHANCED DEGRADATION OF EGF RECEPTORS BY A SORTING NEXIN, SNX1

The vectorial movement of proteins requires specific recognition by co mponents of the vesicular trafficking machinery. A protein, sorting ne xin-1 (SNX1), was identified in a human cell line that bound to a regi on of the epidermal growth factor receptor (EGFR) containing the lysos omal targeting code, SNX1 contains a region of homology to a yeast vac uolar sorting protein, and overexpression of SNX1 decreased the amount of EGFR on the cell surface as a result of enhanced rates of constitu tive and ligand-induced degradation. Thus, SNX1 is likely to play a ro le in sorting EGFR to lysosomes.