Varikmaa 2014 Biochim Biophys Acta
|Varikmaa M, Bagur R, Kaambre T, Grichine A, Timohhina N, Tepp K, Shevchuk I, Chekulayev V, Metsis M, Boucher F, Saks V, Kuznetsov AV, Guzun R (2014) Role of mitochondria-cytoskeleton interactions in respiration regulation and mitochondrial organization in striated muscles. Biochim Biophys Acta 1837:232-45.|
Abstract: The aim of this work was to study the regulation of respiration and energy fluxes in permeabilized oxidative and glycolytic skeletal muscle fibers, focusing also on the role of cytoskeletal protein tubulin βII isotype in mitochondrial metabolism and organization. By analyzing accessibility of mitochondrial ADP, using respirometry and pyruvate kinase-phosphoenolpyruvate trapping system for ADP, we show that the apparent affinity of respiration for ADP can be directly linked to the permeability of the mitochondrial outer membrane (mtOM). Previous studies have shown that mtOM permeability in cardiomyocytes can be regulated by VDAC interaction with cytoskeletal protein, βII tubulin. We found that in oxidative soleus skeletal muscle the high apparent Km for ADP is associated with low mtOM permeability and high expression of non-polymerized βII tubulin. Very low expression of non-polymerized form of βII tubulin in glycolytic muscles is associated with high mtOM permeability for adenine nucleotides (low apparent Km for ADP).
• Keywords: Energy flux, Intracellular energy unit, Metabolic control analysis, Respiration, Skeletal muscle
Labels: MiParea: Respiration, mt-Membrane, Comparative MiP;environmental MiP
Organism: Rat Tissue;cell: Heart, Skeletal muscle Preparation: Permeabilized cells, Isolated mitochondria
Regulation: Inhibitor, PCr;Cr Coupling state: LEAK, OXPHOS Pathway: N, CIV HRR: Oxygraph-2k