Phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2) specifically induces membrane penetration and deformation by Bin/amphiphysin/Rvs (BAR) domains.
Cellular proteins containing Bin/amphiphysin/Rvs (BAR) domains play a key role in clathrin-mediated endocytosis. Despite extensive structural and functional studies of BAR domains, it is still unknown how exactly these domains interact with the plasma membrane containing phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P(2)) and whether they function by a universal mechanism or by different mechanisms. Here we report that PtdIns(4,5)P(2) specifically induces partial membrane penetration of the N-terminal amphiphilic α-helix (H(0)) of two representative N-BAR domains from Drosophila amphiphysin (dAmp-BAR) and rat endophilin A1 (EndoA1-BAR). Our quantitative fluorescence imaging analysis shows that PtdIns(4,5)P(2)-dependent membrane penetration of H(0) is important for self-association of membrane-bound dAmp-BAR and EndoA1-BAR and their membrane deformation activity. EndoA1-BAR behaves differently from dAmp-BAR because the former has an additional amphiphilic α-helix that penetrates the membrane in a PtdIns(4,5)P(2)-independent manner. Depletion of PtdIns(4,5)P(2) from the plasma membrane of HEK293 cells abrogated the membrane deforming activity of EndoA1-BAR and dAmp-BAR. Collectively, these studies suggest that the local PtdIns(4,5)P(2) concentration in the plasma membrane may regulate the membrane interaction and deformation by N-BAR domain-containing proteins during clathrin-mediated endocytosis.
Department of Chemistry, University of Illinois, Chicago, Illinois 60607, USA.
Youngdae
Y
Yoon
Xiuqi
X
Zhang
Wonhwa
W
Cho
D000217:Acyltransferases / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D002462:Cell Membrane / Q000235:genetics / Q000378:metabolism*; D002966:Clathrin / Q000235:genetics / Q000378:metabolism; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster; D004705:Endocytosis / Q000502:physiology; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000378:metabolism*; D057809:HEK293 Cells; D006801:Humans; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D019269:Phosphatidylinositol 4,5-Diphosphate / Q000235:genetics / Q000378:metabolism*; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D051381:Rats
D002966:Clathrin; D029721:Drosophila Proteins; D051858:Forkhead Transcription Factors; D009419:Nerve Tissue Proteins; D019269:Phosphatidylinositol 4,5-Diphosphate; C440017:bin protein, Drosophila; C075637:amphiphysin; D000217:Acyltransferases; C018764:2-acylglycerophosphate acyltransferase