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Regions of the amino terminus of the P2X 1 receptor required for modification by phorbol ester and mGluR1α receptors
Author(s) -
Wen Hairuo,
Evans Richard J.
Publication year - 2009
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.2008.05761.x
Subject(s) - receptor , xenopus , transmembrane domain , long term potentiation , biology , mutant , microbiology and biotechnology , protein kinase c , biochemistry , signal transduction , gene
The potentiation of P2X 1 receptor currents by phorbol ester (PMA) treatment and stimulation of mGluR1α receptors was sensitive to inhibition of novel forms of protein kinase C. Potentiation was also reduced by co‐expression of an amino terminal P2X 1 receptor minigene. Cysteine point mutants of residues Tyr 16 ‐Gly 30 were expressed in Xenopus oocytes. Peak current amplitudes to ATP for Y16C, T18C and R20C mutants were reduced, however this did not result from a decrease in surface expression of the channels. The majority of the mutants showed changes in the time‐course of desensitization of ATP evoked currents indicating the important role of this region in regulation of channel properties. PMA and mGluR1α potentiation was abolished for the mutants Y16C, T18C, R20C, K27C and G30C. Minigenes incorporating either Y16C, K27C, V29C or G30C still inhibited PMA responses. However D17C, T18C or R20C mutant minigenes were no longer effective suggesting that these residues are important for interaction with regulatory factors. These results demonstrate that the conserved YXTXK/R sequence and a region with a conserved glycine residue close to the first transmembrane segment contribute to PMA and GPCR regulation of P2X 1 receptors.