Structure-function relationship of parathyroid hormone: activation of phospholipase-C, protein kinase-A and -C in osteosarcoma cells.
Structure-function relationship of parathyroid hormone: activation of phospholipase-C, protein kinase-A and -C in osteosarcoma cells.
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DOI：
10.1210/endo.130.1.1727705
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发表时间：
1992
期刊：
影响因子：
4.8
通讯作者：
Akira Fujimori;Su‐Li Cheng;L. Avioli;Roberto Civitelli
中科院分区：
文献类型：
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作者：
Akira Fujimori;Su‐Li Cheng;L. Avioli;Roberto Civitelli
最近的证据表明，PTh与其受体相互作用后，蛋白激酶- a （PKA）和蛋白激酶- c （PKC）都被激活。为了探讨PTH结构与蛋白激酶刺激之间的关系，我们分析了合成PTH片段对大鼠成骨肉瘤细胞umr106 -01中PKA和PKC的影响。10(-7) M牛(b) PTH-(1-34)对PKA的激活在5分钟达到最大（对照的2.7倍），并在激素暴露后15分钟保持升高。等摩尔剂量的bPTH-(2-34)也能刺激PKA，但效力较低（为对照的1.4倍），而丙基bPTH-(2-34) [pbPTH-(2-34)]、bPTH-(3-34)、[Tyr34]bPTH-(7-34)酰胺[bPTH-(7-34)]和bPTH-(30-34)无效。另一方面，暴露于bPTH-(1-34)后，PKC活性从细胞质转移到膜是短暂的，在1分钟达到峰值（是对照的1.9倍），并在5分钟后恢复到基础水平。其他片段bPTH-(2-34)、pbPTH-(2-34)、bPTH-(3-34)和bPTH-(7-34)对PKC也有活性，bPTH-(1-34)的相对效力分别为81%、67%、62%和51%，而bPTH-(30-34)则无活性。bPTH-(1-34)、bPTH-(2-34)、pbPTH-(2-34)、bPTH-(2-34)和bPTH-(3-34)也能诱导肌醇1,4,5-三磷酸的产生，其效价分别是对照值的1.6-、1.6-、1.5-和1.6倍，表明磷脂酶c被激活。bPTH-(7-34)和bPTH-(30-34)均未引起肌醇1,4,5-三磷酸产量的统计学显著增加。这些结果表明，PTH信号转导可以通过两种不同的途径分离；cAMP/PKA系统的激活需要氨基酸1和2，而磷脂酶- c /PKC系统与激素n端较长的结构域偶联。
Recent evidence indicates that after PTh interaction with its receptor, both protein kinase-A (PKA) and protein kinase-C (PKC) are activated. To investigate the relationship between PTH structure and protein kinase stimulation, we have analyzed the effects of synthetic PTH fragments on PKA and PKC in the rat osteogenic sarcoma cells, UMR 106-01. Activation of PKA by 10(-7) M bovine (b) PTH-(1-34) was maximal (2.7-fold of control) at 5 min and remained elevated 15 min after hormone exposure. bPTH-(2-34), at equimolar doses, also stimulated PKA, but with a lower potency (1.4-fold of control), whereas propionyl bPTH-(2-34) [pbPTH-(2-34)], bPTH-(3-34), [Tyr34]bPTH-(7-34) amide [bPTH-(7-34)], and bPTH-(30-34) were ineffective. On the other hand, translocation of PKC activity from the cytosol to the membrane after exposure to bPTH-(1-34) was transient, with a peak at 1 min (1.9-fold of control), and returned to basal levels after 5 min. Other fragments, bPTH-(2-34), pbPTH-(2-34), bPTH-(3-34), and bPTH-(7-34), were also active on PKC, with relative potencies of 81%, 67%, 62%, and 51% of bPTH-(1-34), respectively, whereas bPTH-(30-34) was inactive. bPTH-(1-34), bPTH-(2-34), pbPTH-(2-34), and bPTH-(3-34) also induced inositol 1,4,5-trisphosphate production, with a potency order of 1.6-, 1.6-, 1.5-, and 1.6-fold over the control value, respectively, thus indicating activation of phospholipase-C. Neither bPTH-(7-34) nor bPTH-(30-34) caused a statistically significant increase in inositol 1,4,5-trisphosphate production. These results demonstrate that PTH signal transduction through the two different pathways can be dissociated; while activation of the cAMP/PKA system requires amino acids 1 and 2, the phospholipase-C/PKC system is coupled to a longer domain of the hormone's N-terminus.