Human reticulon 1-A and 1-B interact with a medium chain of the AP-2 adaptor complex.

Human reticulon family gene 1 (RTN1) is expressed predominantly in neuroendocrine tissues, and produces three proteins termed RTN1-A, RTN1-B, and RTN1-C. Yeast two-hybrid screening indicated that RTN1-A and RTN1-B interacted with AP50, a component of the AP-2 adaptor complex involved in endocytosis. In contrast, RTN1-C did not interact with AP50. Three RTN1 proteins contain the same C-terminal domain. In addition, RTN1-A and RTN1-B share N-terminal 168 amino acid region, suggesting that the 168 amino acid region might play a role in regulating the endocytic process. Although no apparent morphological change of the endocytic organelles was observed, the association of AP50 with the internalized clathrin-coated vesicles was moderately affected when CV-1 cells were directed to express stably RTN1-A or RTN1-B.