Multiple signals regulate phospholipase CBeta3 in human myometrial cells.
Multiple signals regulate phospholipase CBeta3 in human myometrial cells.
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DOI：
10.1095/biolreprod.107.064485
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发表时间：
2008-06
影响因子：
3.6
通讯作者：
M. Zhong;D. Murtazina;J. Phillips;C. Ku;B. Sanborn
中科院分区：
文献类型：
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作者：
M. Zhong;D. Murtazina;J. Phillips;C. Ku;B. Sanborn
磷脂酶CB 3（PLCB 3）丝氨酸（1105）（S（1105））是多种蛋白激酶的底物，代表了子宫肌层中几种信号通路的潜在汇聚点。为了探索这一假设，在永生化和原代人子宫肌层细胞中研究了PLCB 3-S（1105）磷酸化（P-S（1105））的调节。8-[4-氯苯硫基]（CPT）-cAMP和降钙素基因相关肽（CALCA）短暂增加P-S（1105）。松弛素也刺激P-S（1105）;这种作用被蛋白激酶A（PRKA）抑制剂Rp-8-CPT-cAMPS部分阻断。催产素，刺激Galphaq介导的途径，也迅速增加P-S（1105），前列腺素F2 α和ATP也是如此。催产素刺激的磷酸化被蛋白激酶C（PRKC）抑制剂Go 6976阻断，并通过用佛波酯预处理过夜。氯氰菊酯（一种PP 2B磷酸酶抑制剂）延长了CALCA对P-S的作用（1105），而冈田酸（一种PP 1/PP 2A抑制剂）则没有延长，而催产素刺激的P-S增加则相反（1105）。PLCB 3是子宫肌层细胞中表达的主要PLC同种型，PLCB 3短发夹RNA构建体显著减弱催产素刺激的细胞内钙增加。催产素诱导的磷脂酰肌醇（PI）的营业额被抑制CPT-cAMP和冈田酸，但增强预处理与Go 6976。CPT-cAMP在存在过表达的PLCB 3的情况下抑制催产素刺激的PI转换，但不存在过表达的PLCB 3-S（1105）A。这些数据表明，来自cAMP/PRKA途径的负串扰和涉及PRKC的催产素/G蛋白/PLCB途径中的负反馈环在子宫肌层细胞中起作用，并表明不同的蛋白磷酸酶在介导这些途径中的P-S（1105）去磷酸化中占主导地位。PLCB 3水平上的多个信号成分的整合可能对其在子宫肌层中的功能很重要。
Phospholipase CB3 (PLCB3) serine(1105) (S(1105)), a substrate for multiple protein kinases, represents a potential point of convergence of several signaling pathways in the myometrium. To explore this hypothesis, the regulation of PLCB3-S(1105) phosphorylation (P-S(1105)) was studied in immortalized and primary human myometrial cells. 8-[4-chlorophenylthio] (CPT)-cAMP and calcitonin gene-related peptide (CALCA) transiently increased P-S(1105). Relaxin also stimulated P-S(1105); this effect was partially blocked by the protein kinase A (PRKA) inhibitor, Rp-8-CPT-cAMPS. Oxytocin, which stimulates Galphaq-mediated pathways, also rapidly increased P-S(1105), as did prostaglandin F2alpha and ATP. Oxytocin-stimulated phosphorylation was blocked by protein kinase C (PRKC) inhibitor Go6976 and by pretreatment overnight with a phorbol ester. Cypermethrin, a PP2B phosphatase inhibitor, but not okadaic acid, a PP1/PP2A inhibitor, prolonged the effect of CALCA on P-S(1105), whereas the reverse was the case for the oxytocin-stimulated increase in P-S(1105). PLCB3 was the predominant PLC isoform expressed in the myometrial cells and PLCB3 short hairpin RNA constructs significantly attenuated oxytocin-stimulated increases in intracellular calcium. oxytocin-induced phosphatidylinositol (PI) turnover was inhibited by CPT-cAMP and okadaic acid, but was enhanced by pretreatment with Go6976. CPT-cAMP inhibited oxytocin-stimulated PI turnover in the presence of overexpressed PLCB3, but not overexpressed PLCB3-S(1105)A. These data demonstrate that both negative crosstalk from the cAMP/PRKA pathway and a negative feedback loop in the oxytocin/G protein/PLCB pathway involving PRKC operate in myometrial cells and suggest that different protein phosphatases predominate in mediating P-S(1105) dephosphorylation in these pathways. The integration of multiple signal components at the level of PLCB3 may be important to its function in the myometrium.