Date of Graduation

Spring 2009


Master of Science in Cell and Molecular Biology


Biomedical Sciences

Committee Chair

Richard Garrad


desensitization, G protein, mutant, receptor, MAPK pathway

Subject Categories

Medical Molecular Biology


P2Y2 nucleotide receptors are G protein-coupled receptors (GPCR). P2Y2 receptors increase intracellular calcium, as a result of an activation of the phospholipase C pathway, involving the production of inositol-1,4,5-triphosphate. Diacylglycerol is also produced during this process which activates protein kinase C. In order to investigate further the mechanism of P2Y2 receptor activation and desensitization, four mutants were created within the cytoplasmic tail of the P2Y2 receptor and expressed in 1321N1 human astrocytoma cells that did not previously contain P2Y2 receptors. The cells expressing the altered receptors were then tested in order to determine the mobilization of intracellular free calcium. The concentration response curves of intracellular free calcium increased in all four sets of P2Y2 mutant cell lines, leading to signaling and desensitization similar to that found with the wild type receptor. As a result, these particular locations within the cytoplasmic tail of the P2Y2 receptor are not vital to the activation of the phospholipase C pathway. Further investigation is necessary in order to determine whether other possible locations within the cytoplasmic tail of the P2Y2 receptor play a role in the regulation of the signaling activity.KEYWORDS: Desensitization, G protein, Mutant, Receptor, MAPK pathway


© Amy Katherine Schiller

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