cAMP-dependent protein kinase regulates post-translational processing and expression of complex I subunits in mammalian cells.

Department of Medical Biochemistry, Biology and Physics (DIBIFIM), University of Bari, Bari, Italy.
Biochimica et Biophysica Acta (Impact Factor: 4.66). 03/2010; 1797(6-7):649-58. DOI: 10.1016/j.bbabio.2010.03.013
Source: PubMed

ABSTRACT Work is presented on the role of cAMP-dependent protein phosphorylation in post-translational processing and biosynthesis of complex I subunits in mammalian cell cultures. PKA-mediated phosphorylation of the NDUFS4 subunit of complex I promotes in cell cultures in vivo import/maturation in mitochondria of the precursor of this protein. The import promotion appears to be associated with the observed cAMP-dependent stimulation of the catalytic activity of complex I. These effects of PKA are counteracted by activation of protein phosphatase(s). PKA and the transcription factor CREB play a critical role in the biosynthesis of complex I subunits. CREB phosphorylation, by PKA and/or CaMKs, activates at nuclear and mitochondrial level a transcriptional regulatory cascade which promotes the concerted expression of nuclear and mitochondrial encoded subunits of complex I and other respiratory chain proteins.

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