Role of DAKAPs in Mitochondrial Function

DAKAP 在线粒体功能中的作用

基本信息

批准号：
6445718
负责人：
Kenneth M Humphries
金额：
$ 3.83万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN DIEGO
依托单位国家：
美国
项目类别：
财政年份：
2002
资助国家：
美国
起止时间：
2002-03-01 至
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/6445718
关键词：
A kinase anchoring protein G protein cyclic AMP cytochrome c intracellular transport laboratory mouse mitochondria phosphoproteins phosphorylation protein kinase A protein structure function protein transport

项目摘要

Relatively little is known about second messenger signaling to mitochondria. In recent years though, a number of substrates have been identified in this organelle that are phosphorylated in a cAMP-dependent manner. These substrates have been identified in this organelle that are phosphorylated in a cAMP-dependent manner. These substrates including electron transport chain components and the proapoptotic protein, BAD, suggest a physiological role for cAMP-dependant protein kinase (PKA) in mitochondria. Experiments performed in the Taylor laboratory have identified two new AKAPs (D=AKAPs) are localized to the mitochondria. D-AKAP1 contains 30 amino acids at the NH2- terminus that are sufficient for targeting to the outer mitochondrial membrane, while preliminary studies suggest D-AKAP2 localizes to the matrix. Interestingly, D-AKAP2 also contains two putative PGS domains, sites capable of binding Galpha subunits and leading to speculation that D-AKAP2 may be a scaffolding protein capable of co- localizing multiple signaling molecules. We hypothesize that PKA's role in altering specific mitochondrial functions is mediated by its association with these novel anchoring proteins. To test this hypothesis, this research proposes to identify substrates phosphorylated by PKA as a consequence of this association with the AKAPs. Because of the biochemical differences between RI and RII isoforms, the relative effect of PKA on mitochondrial function may be a function of which isoform is bound to the anchoring protein. This research will thus seek to determine the relative significance of RI versus RII isoform anchoring in mitochondria. Finally, experiments will be performed to determine what proteins, in addition to PKA, are bound to D-AKAP2 in mitochondria.

关于线粒体第二信使信号传导的了解相对较少。然而，近年来，在该细胞器中已鉴定出许多以 cAMP 依赖性方式磷酸化的底物。已在该细胞器中鉴定出这些底物以 cAMP 依赖性方式磷酸化。这些底物包括电子传递链成分和促凋亡蛋白 BAD，表明 cAMP 依赖性蛋白激酶 (PKA) 在线粒体中具有生理作用。 Taylor 实验室进行的实验已确定两个新的 AKAP (D=AKAP) 定位于线粒体。 D-AKAP1 在 NH2 末端含有 30 个氨基酸，足以靶向线粒体外膜，而初步研究表明 D-AKAP2 定位于基质。有趣的是，D-AKAP2 还包含两个假定的 PGS 结构域，这些位点能够结合 Galpha 亚基，并导致推测 D-AKAP2 可能是能够共定位多个信号分子的支架蛋白。我们假设 PKA 在改变特定线粒体功能中的作用是通过其与这些新型锚定蛋白的关联来介导的。为了检验这一假设，本研究建议鉴定因与 AKAP 相关而被 PKA 磷酸化的底物。由于 RI 和 RII 异构体之间的生化差异，PKA 对线粒体功能的相对影响可能是哪种异构体与锚定蛋白结合的函数。因此，本研究将寻求确定 RI 与 RII 亚型锚定在线粒体中的相对重要性。最后，将进行实验以确定除 PKA 之外还有哪些蛋白质与线粒体中的 D-AKAP2 结合。