Protein kinase C-alpha inhibits the repair of oxidative phosphorylation after S-(1,2-dichlorovinyl)-L-cysteine injury in renal cells.
Protein kinase C-alpha inhibits the repair of oxidative phosphorylation after S-(1,2-dichlorovinyl)-L-cysteine injury in renal cells.
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蛋白激酶 C-α 抑制肾细胞 S-(1,2-二氯乙烯基)-L-半胱氨酸损伤后氧化磷酸化的修复。
DOI：
10.1152/ajprenal.00216.2003
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
Nowak,Grazyna
中科院分区：
文献类型：
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作者：
Liu,Xiuli;Godwin,MalindaL;Nowak,Grazyna
以前，我们发现肾近端小管细胞（RPTC）的生理功能不能在S-（1，2-二氯乙烯基）-L-半胱氨酸（DCVC）诱导的损伤后恢复。本研究探讨蛋白激酶C-α（PKC-α）在DCVC损伤的RPTC中线粒体功能修复缺失中的作用。DCVC暴露后，基础耗氧量（Qo 2），非偶联Qo 2，寡霉素敏感的Qo 2，F1 F0-ATP酶活性，ATP生产，分别下降到59，27，27，57，和68%的控制。这些功能都没有恢复。DCVC损伤后线粒体跨膜电位下降53%，但在第4天恢复。PKC-α在恢复期第2天和第4天分别活化4.3和2.5倍。抑制PKC-α激活（10 nM Go 6976）并不能阻断DCVC诱导的线粒体功能下降，但能促进非偶联Qo 2、寡霉素敏感性Qo 2、F1 F0-ATP酶活性和ATP生成的恢复。DCVC和恢复期F1 F0-ATP酶催化β亚基蛋白水平无明显变化。氨基酸序列分析表明，F1 F0-ATP酶的α-、β-和ε-亚基具有PKC共有基序。重组PKC-α使β-亚基磷酸化，降低F1 F0-ATP酶活性。在DCVC损伤后的恢复后期，β亚基的丝氨酸磷酸化而非苏氨酸磷酸化增加，抑制PKC-α活化可降低这种磷酸化。结论：在DCVC损伤后RPTC恢复过程中，1）PKC-α激活降低F0 F1-ATP酶活性、氧化磷酸化和ATP生成;2）PKC-α磷酸化丝氨酸残基上的F1 F0-ATP酶β亚基; 3）PKC-α不介导RPTC线粒体的去极化。这是首次报道PKC-α磷酸化F1 F0-ATP酶的催化亚基，并且PKC-α在调节线粒体功能修复中起重要作用。
Previously, we showed that physiological functions of renal proximal tubular cells (RPTC) do not recover followingS-(1,2-dichlorovinyl)-l-cysteine (DCVC)-induced injury. This study investigated the role of protein kinase C-α (PKC-α) in the lack of repair of mitochondrial function in DCVC-injured RPTC. After DCVC exposure, basal oxygen consumption (Qo2), uncoupled Qo2, oligomycin-sensitive Qo2, F1F0-ATPase activity, and ATP production decreased, respectively, to 59, 27, 27, 57, and 68% of controls. None of these functions recovered. Mitochondrial transmembrane potential decreased 53% after DCVC injury but recovered onday 4. PKC-α was activated 4.3- and 2.5-fold ondays 2and4, respectively, of the recovery period. Inhibition of PKC-α activation (10 nM Go6976) did not block DCVC-induced decreases in mitochondrial functions but promoted the recovery of uncoupled Qo2, oligomycin-sensitive Qo2, F1F0-ATPase activity, and ATP production. Protein levels of the catalytic β-subunit of F1F0-ATPase were not changed by DCVC or during the recovery period. Amino acid sequence analysis revealed that α-, β-, and ε-subunits of F1F0-ATPase have PKC consensus motifs. Recombinant PKC-α phosphorylated the β-subunit and decreased F1F0-ATPase activity in vitro. Serine but not threonine phosphorylation of the β-subunit was increased during late recovery following DCVC injury, and inhibition of PKC-α activation decreased this phosphorylation. We conclude that during RPTC recovery following DCVC injury,1) PKC-α activation decreases F0F1-ATPase activity, oxidative phosphorylation, and ATP production;2) PKC-α phosphorylates the β-subunit of F1F0-ATPase on serine residue; and3) PKC-α does not mediate depolarization of RPTC mitochondria. This is the first report showing that PKC-α phosphorylates the catalytic subunit of F1F0-ATPase and that PKC-α plays an important role in regulating repair of mitochondrial function.