title: Mitochondria-cytoskeleton interaction: distribution of β-tubulins in cardiomyocytes and HL-1 cells.
abstract: Mitochondria-cytoskeleton interactions were analyzed in adult rat cardiomyocytes and in cancerous non-beating HL-1 cells of cardiac phenotype. We show that in adult cardiomyocytes βII-tubulin is associated with mitochondrial outer membrane (MOM). βI-tubulin demonstrates diffused intracellular distribution, βIII-tubulin is colocalized with Z-lines and βIV-tubulin forms microtubular network. HL-1 cells are characterized by the absence of βII-tubulin, by the presence of bundles of filamentous βIV-tubulin and diffusely distributed βI- and βIII-tubulins. Mitochondrial isoform of creatine kinase (MtCK), highly expressed in cardiomyocytes, is absent in HL-1 cells. Our results show that high apparent K(m) for exogenous ADP in regulation of respiration and high expression of MtCK both correlate with the expression of βII-tubulin. The absence of βII-tubulin isotype in isolated mitochondria and in HL-1 cells results in increased apparent affinity of oxidative phosphorylation for exogenous ADP. This observation is consistent with the assumption that the binding of βII-tubulin to mitochondria limits ADP/ATP diffusion through voltage-dependent anion channel of MOM and thus shifts energy transfer via the phosphocreatine pathway. On the other hand, absence of both βII-tubulin and MtCK in HL-1 cells can be associated with their more glycolysis-dependent energy metabolism which is typical for cancer cells (Warburg effect).
authors.affiliation: INSERM U884, Laboratory of Fundamental and Applied Bioenergetics, Joseph Fourier University, Grenoble, France.
authors.forename: Rita
authors.initials: R
authors.lastname: Guzun
authors.forename: Minna
authors.initials: M
authors.lastname: Karu-Varikmaa
authors.forename: Marcela
authors.initials: M
authors.lastname: Gonzalez-Granillo
authors.forename: Andrey V
authors.initials: AV
authors.lastname: Kuznetsov
authors.forename: Lauriane
authors.initials: L
authors.lastname: Michel
authors.forename: Cécile
authors.initials: C
authors.lastname: Cottet-Rousselle
authors.forename: Merle
authors.initials: M
authors.lastname: Saaremäe
authors.forename: Tuuli
authors.initials: T
authors.lastname: Kaambre
authors.forename: Madis
authors.initials: M
authors.lastname: Metsis
authors.forename: Michael
authors.initials: M
authors.lastname: Grimm
authors.forename: Charles
authors.initials: C
authors.lastname: Auffray
authors.forename: Valdur
authors.initials: V
authors.lastname: Saks
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D003599:Cytoskeleton / Q000378:metabolism*; D051379:Mice; D008928:Mitochondria / Q000378:metabolism*; D032383:Myocytes, Cardiac / Q000378:metabolism*; D014404:Tubulin / Q000378:metabolism*
chemical_list: D014404:Tubulin