CYCLIC GMP METABOLISM IN CELLULAR DEFFERENTIATION AND FUNCTION

环3‘：5’核苷酸(CNMP)代谢的变化发生在 交感神经功能障碍。PC12细胞向成骨细胞分化的研究 交感神经元表型伴有明显的cNMP改变 磷酸二酯酶(PDE)。神经生长因子(NGF)或钒酸盐减少 CGMP刺激PC12细胞PDE(PDE-2基因产物)50% 24小时后。NGF不会降低PDE-2m RNA，而是增加 钙调素刺激PDE(PDE-1基因)基因的表达。富有同情心 分化可能将cNMP的代谢从cGMP调节转变为 钙调节状态。为了研究这一点，PC12细胞中的PDE cDNA 交感神经节将通过分子克隆和 表情。2)NGF对PDE基因和蛋白表达的影响 被评估。3)磷酸化在PDE调控中的作用 活性将通过磷酸多肽作图和位点定向来确定 诱变和表达研究。

Changes in cyclic 3':5' nucleotide (cNMP) metabolism occur in sympathetic dysfunction. Differentiation of PC12 cells into a sympathetic neuronal phenotype is accompanied by changes distinct cNMP phosphodiesterases (PDEs). Nerve growth factor (NGF) or vanadate reduce cGMP- stimulated PDE (the PDE 2 gene product) in PC12 cells by 50 % after 24 hours. NGF does not decrease PDE 2 mRNA, but increase calmodulin- stimulated PDE (the PDE 1 gene) mRNA. Sympathetic differentiation may shift cNMP metabolism from a cGMP- regulated to a calcium-regulated state. To study this 1), PDE cDNAs from PC12 cells and sympathetic ganglia will be characterized by molecular cloning and expression. 2) NGF effects on PDE mRNA and protein expression will be assessed. 3) The role of phosphorylation in the regulation of PDE activity will be determined by phosphopeptide mapping and site directed mutagenesis and expression studies.