Evidence of undiscovered cell regulatory mechanisms: phosphoproteins and protein kinases in mitochondria.
The finding that mitochondria contain substrates for protein kinases lead to the discovery that protein kinases are located in the mitochondria of certain tissues and species. These include pyruvate dyhydrogenase kinase, branched-chain alpha-ketoacid dehydrogenase kinase, protein kinase A, protein kinase Cdelta, stress-activated kinase and A-Raf as well as unidentified kinases. Recent evidence suggests that mitochondrial protein kinases may be involved in physiological processes such as apoptosis and steroidogenesis. Additionally, the novel finding of low-molecular-weight GTP-binding proteins in mitochondria suggests the possibility that these may interact with mitochondrial protein kinases to regulate the activity of mitochondrial effector proteins. The fact that there are components of cellular regulatory systems in mitochondria indicates the exciting possibility of undiscovered systems regulating mitochondrial physiology.
Thomson
M
M
School of Biological Sciences, The University of Sydney, New South Wales, Australia.
D000818:Animals; D017209:Apoptosis; D005075:Biological Evolution; D019069:Cell Respiration; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D008928:Mitochondria / Q000201:enzymology* / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism*; D008954:Models, Biological; D020559:Monomeric GTP-Binding Proteins / Q000502:physiology; D010750:Phosphoproteins / Q000378:metabolism*; D011494:Protein Kinases / Q000378:metabolism; D013256:Steroids / Q000096:biosynthesis
D024101:Mitochondrial Proteins; D010750:Phosphoproteins; D013256:Steroids; D011494:Protein Kinases; D017868:Cyclic AMP-Dependent Protein Kinases; D020559:Monomeric GTP-Binding Proteins