Low mobility of phosphatidylinositol 4,5-bisphosphate underlies receptor specificity of Gq-mediated ion channel regulation in atrial myocytes.
AuthorsCho H, Kim YA, Yoon JY, Lee D, Kim JH, Lee SH, Ho WK
JournalProc Natl Acad Sci U S A
PubMed ID16217031
'We have shown previously that cardiac G protein-gated inwardly rectifying K+ (GIRK) channels are inhibited by Gq protein-coupled receptors (GqPCRs) via phosphatidylinositol 4,5-bisphosphate (PIP2) depletion in a receptor-specific manner. To investigate the mechanism of receptor specificity, we examined whether the activation of GqPCRs induces localized PIP2 depletion. When we applied ... More
EphrinB-EphB signalling regulates clathrin-mediated endocytosis through tyrosine phosphorylation of synaptojanin 1.
AuthorsIrie F, Okuno M, Pasquale EB, Yamaguchi Y
JournalNat Cell Biol
PubMed ID15821731
'Recent studies show that Eph receptors act mainly through the regulation of actin reorganization. Here, we show a novel mode of action for EphB receptors. We identify synaptojanin 1 - a phosphatidylinositol 5''-phosphatase that is involved in clathrin-mediated endocytosis - as a physiological substrate for EphB2. EphB2 causes tyrosine phosphorylation ... More
Cholesterol-dependent partitioning of PtdIns(4,5)P2 into membrane domains by the N-terminal fragment of NAP-22 (neuronal axonal myristoylated membrane protein of 22 kDa).
AuthorsEpand RM, Vuong P, Yip CM, Maekawa S, Epand RF
JournalBiochem J
PubMed ID14989697
A myristoylated peptide corresponding to the N-terminus of NAP-22 (neuronal axonal myristoylated membrane protein of 22 kDa) causes the quenching of the fluorescence of BODIPY-TMR-labelled PtdIns(4,5) P2 in bilayers of 1-palmitoyl-2-oleoyl phosphatidylcholine containing 40 mol% cholesterol and 0.1 mol% BODIPY-PtdIns(4,5)2. Both fluorescence spectroscopy and total internal reflectance fluorescence microscopy revealed ... More