甲状腺激素对线粒体蛋白质周转的调节

Regulation of mitochondrial protein turnover by thyroid hormone(s).

作者信息

Rajwade M S, Katyare S S, Fatterpaker P, Sreenivasan A

出版信息

Biochem J. 1975 Nov;152(2):379-87. doi: 10.1042/bj1520379.

DOI:10.1042/bj1520379

PMID:177002

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC1172481/

Abstract

The effect of thyroidectomy on turnover rates of liver, kidney and brain mitochondrial proteins was examined. 2. In the euthyroid state, liver and kidney mitochondria show a synchronous turnover with all protein components showing more or less identical half-lives compared with the whole mitochondria. The brain mitochondrial proteins show asynchronous turnover, the soluble proteins having shorter half-lives. 3. Mitochondrial DNA (m-DNA) of liver and kidney has half-lives comparable with that of whole mitochondria from these tissues. 4. Thyroidectomy results in increased half-lives of liver and kidney mitochondria, with no apparent change in the half-life of brain mitochondria. 5. A detailed investigation of the turnover rates of several protein components revealed a significant decrease in the turnover rates of mitochondrial insoluble proteins from the three tissues under study. 6. The turnover rates of m-DNA of liver and kidney show a parallel decrease. 7. Thus it is apparent that thyroid hormone(s) may have a regulatory role in maintaining the synchrony of turnover of liver and kidney mitochondria in the euthyroid state. Turnover of brain mitochondria may perhaps be regulated by some other factor(s) in addition to thyroid hormone(s). 8. It seems likely that during mitochondrial turnover m-DNA and insoluble proteins may constitute a major unit. 9. The mitochondrial protein contents of the three tissues are not affected by thyroidectomy. 10. No correlation was seen between the turnover rate of mitochondria and cathepsin activity in any of the tissues under study in normal or thyroidectomized animals. 11. On the other hand, mitochondrial proteinase activity shows good correlation with the turnover rates of mitochondria in normal animals, and a parallel decrease in activity comparable with the decreased rates of turnover is observed after thyroidectomy. 12. It is concluded that mitochondrial proteinase activity may play a significant role in their protein turnover.

摘要

研究了甲状腺切除对肝脏、肾脏和脑线粒体蛋白质更新率的影响。2. 在甲状腺功能正常状态下，肝脏和肾脏线粒体显示出同步更新，与整个线粒体相比，所有蛋白质组分的半衰期或多或少相同。脑线粒体蛋白质显示出不同步更新，可溶性蛋白质的半衰期较短。3. 肝脏和肾脏的线粒体DNA（m-DNA）半衰期与这些组织的整个线粒体的半衰期相当。4. 甲状腺切除导致肝脏和肾脏线粒体的半衰期增加，而脑线粒体的半衰期没有明显变化。5. 对几种蛋白质组分更新率的详细研究表明，所研究的三种组织中线粒体不溶性蛋白质的更新率显著降低。6. 肝脏和肾脏m-DNA的更新率呈现平行下降。7. 因此，显然甲状腺激素可能在维持甲状腺功能正常状态下肝脏和肾脏线粒体更新的同步性方面具有调节作用。脑线粒体的更新可能除甲状腺激素外还受其他一些因素调节。8. 在细胞器更新过程中，m-DNA和不溶性蛋白质似乎可能构成一个主要单位。9. 甲状腺切除不影响这三种组织的线粒体蛋白质含量。10. 在正常或甲状腺切除的动物中，所研究的任何组织中线粒体的更新率与组织蛋白酶活性之间均未发现相关性。11. 另一方面，线粒体蛋白酶活性在正常动物中与线粒体的更新率显示出良好的相关性，甲状腺切除后观察到其活性平行下降，与更新率降低相当。12. 得出的结论是，线粒体蛋白酶活性可能在其蛋白质更新中起重要作用。