gamma-BAR, a novel AP-1-interacting protein involved in post-Golgi trafficking Neubrand, Veronika Elisabeth Will, Rainer D Möbius, Wiebke Poustka, Annemarie Wiemann, Stefan Schu, Peter Dotti, Carlos G Pepperkok, Rainer Simpson, Jeremy C AP-1 Gamma-adaptin A novel peripheral membrane protein (2c18) that interacts directly with the gamma ‘ear’ domain of the adaptor protein complex 1 (AP-1) in vitro and in vivo is described. Ultrastructural analysis demonstrates a colocalization of 2c18 and c1-adaptin at the trans-Golgi network (TGN) and on vesicular profiles. Overexpression of 2c18 increases the fraction of membrane-bound c1-adaptin and inhibits its release from membranes in response to brefeldin A. Knockdown of 2c18 reduces the steady-state levels of c1-adaptin on membranes. Overexpression or downregulation of 2c18 leads to an increased secretion of the lysosomal hydrolase cathepsin D, which is sorted by the mannose-6-phosphate receptor at the TGN, which itself involves AP-1 function for trafficking between the TGN and endosomes. This suggests that the direct interaction of 2c18 and c1-adaptin is crucial for membrane association and thus the function of the AP-1 complex in living cells. We propose to name this protein c-BAR. 2024-01-03T11:30:56Z 2024-01-03T11:30:56Z 2005 info:eu-repo/semantics/article EMBO J 24, 1122–1133 https://hdl.handle.net/10481/86543 10.1038/ sj.emboj.7600600 eng http://creativecommons.org/licenses/by-nc-nd/3.0/ info:eu-repo/semantics/openAccess Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License EMBO Press