UNI-MB - logo
UMNIK - logo
 
E-viri
Recenzirano Odprti dostop
  • Role of mitochondria–cytosk...
    Varikmaa, Minna; Bagur, Rafaela; Kaambre, Tuuli; Grichine, Alexei; Timohhina, Natalja; Tepp, Kersti; Shevchuk, Igor; Chekulayev, Vladimir; Metsis, Madis; Boucher, François; Saks, Valdur; Kuznetsov, Andrey V.; Guzun, Rita

    Biochimica et biophysica acta, February 2014, 2014-Feb, 2014-02-00, 2014-02, Letnik: 1837, Številka: 2
    Journal Article

    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 (MOM). Previous studies have shown that MOM 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 MOM 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 MOM permeability for adenine nucleotides (low apparent Km for ADP). •Mitochondrial sensitivity to ADP is dependent on the outer membrane permeability.•Free βII tubulin may regulate mitochondrial ADP sensitivity in oxidative muscles.•Polymerized βII tubulin contributes to mitochondria location in striated muscles.