Open AccessInositol hexakisphosphate promotes dynamin I- mediated endocytosis
Author(s) -
Marianne Høy,
Alexander M. Efanov,
Alejandro M. Bertorello,
С. В. Зайцев,
Henrik Baare Olsen,
Krister Bokvist,
Barbara Leibiger,
Ingo B. Leibiger,
Jean Zwiller,
Per Olof Berggren,
Jesper Gromada
Publication year - 2002
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.102157499
Subject(s) - endocytosis , exocytosis , dynamin , microbiology and biotechnology , bulk endocytosis , phosphatidylinositol , biology , dephosphorylation , receptor mediated endocytosis , phosphatase , chemistry , signal transduction , secretion , biochemistry , phosphorylation , cell
Membrane homeostasis is maintained by exocytosis and endocytosis. The molecular mechanisms regulating the interplay between these two processes are not clear. Inositol hexakisphosphate (InsP(6)) is under metabolic control and serves as a signal in the pancreatic beta cell stimulus-secretion coupling by increasing Ca(2+)-channel activity and insulin exocytosis. We now show that InsP(6) also promotes dynamin I-mediated endocytosis in the pancreatic beta cell. This effect of InsP(6) depends on calcineurin-induced dephosphorylation and is accounted for by both activation of protein kinase C and inhibition of the phosphoinositide phosphatase synaptojanin and thereby formation of phosphatidylinositol 4,5-bisphosphate. In regulating both exocytosis and endocytosis, InsP(6) thus may have an essential integral role in membrane trafficking.