LOCALIZATION OF CATALYTIC AND REGULATORY SUBUNITS OF CYCLIC AMP-DEPENDENT PROTEIN-KINASES IN MITOCHONDRIA FROM VARIOUS RAT-TISSUES
LOCALIZATION OF CATALYTIC AND REGULATORY SUBUNITS OF CYCLIC AMP-DEPENDENT PROTEIN-KINASES IN MITOCHONDRIA FROM VARIOUS RAT-TISSUES
复制标题
DOI：
10.1042/bj2700181
复制
发表时间：
1990-08-15
影响因子：
4.1
通讯作者：
BODE, C
中科院分区：
文献类型：
--
作者：
SCHWOCH, G;TRINCZEK, B;BODE, C
用免疫金电子显微镜观察和定量cAMP依赖蛋白激酶的催化亚基C亚基表明，肝、肾、心脏和骨骼肌、胰腺、腮腺和脑细胞的线粒体中都有高浓度的cAMP依赖蛋白激酶。金颗粒的位置指向内膜/基质空间的局域化。在肝、胰腺和心脏细胞中，通过免疫定位环状AMP依赖的蛋白激酶调节亚基RI和RII，也获得了类似的分布。结果表明，肝细胞线粒体中存在I型和II型环磷酸腺苷依赖的蛋白激酶，I型蛋白激酶优先存在于外分泌胰腺和心肌的线粒体中。免疫细胞化学结果通过对分离组织中cAMP依赖的蛋白激酶亚基的免疫化学检测得到证实。由E.L.I.S.A.作出的决定。腮腺细胞组分中C亚基的含量表明，线粒体中C亚基的浓度大约是粗制1200g上清液中C亚基浓度的4倍。肝线粒体亚组分的免疫印迹分析支持环磷酸腺苷依赖的蛋白激酶在内膜/基质空间的原位定位，并提示I型酶通过其调节亚基锚定在内膜上。根据免疫印迹数据，在基质组分中测得的cAMP依赖蛋白激酶的比活性大约是在整个线粒体中测量的比活性的两倍。这些发现表明环AMP依赖的蛋白激酶在线粒体功能调节中的重要性。
Observation and quantifications of the catalytic subunit C of cyclic AMP-dependent protein kinases by immuno-gold electron microscopy suggested a high concentration of cyclic AMP-dependent protein kinases in mitochondria from liver, kindey, heart and skeletal muscle, pancreas, parotid gland and brain cells. The position of gold particles pointed to a localization in the inner membrane/matrix space. A similar distribution was obtained by immunolocalization of the cyclic AMP-dependent protein kinase regulatory subunits RI and RII in liver, pancreas and heart cells. The results indicated the presence of both the type I and the type II cyclic AMP-dependent protein kinases in mitochondria of hepatocytes, and the preferential occurrence of the type I protein kinase in mitochondria from exocrine pancreas and heart muscle. The immunocytochemical results were confirmed by immunochemical determination of cyclic AMP-dependent protein kinase subunits in fractionated tissues. Determinations by e.l.i.s.a. of the C-subunit in parotid gland cell fractions indicated about a 4-fold higher concentration of C-subunit in the mitochondria than in a crude 1200 g supernatant. Immunoblot analysis of subfractions from liver mitochondria supported the localization in situ of cyclic AMP-dependent protein kinase in the inner membrane/matrix space and suggested that the type I enzyme is anchored by its regulatory subunit to the inner membrane. In accordance with the immunoblot data, the specific activity of cyclic AMP-dependent protein kinase measured in the matrix fraction was about twice that mesured in whole mitochondria. These findings indicate the importance of cyclic AMP-dependent protein kinases in the regulation of mitochondrial functions.