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Experimental Approaches to Study Mitochondrial Localization and Function of a Nuclear Cell Cycle Kinase, Cdk1
Published on: February 25, 2016
Mitochondria. Cell cycle-dependent regulation of mitochondrial preprotein translocase
Angelika B Harbauer1, Magdalena Opalińska2, Carolin Gerbeth3
1Institut für Biochemie und Molekularbiologie, ZBMZ, Universität Freiburg, 79104 Freiburg, Germany. Trinationales Graduiertenkolleg 1478, Universität Freiburg, 79104 Freiburg, Germany. Faculty of Biology, Universität Freiburg, 79104 Freiburg, Germany. BIOSS Centre for Biological Signalling Studies, Universität Freiburg, 79104 Freiburg, Germany.
Abstract:
Mitochondria play central roles in cellular energy conversion, metabolism, and apoptosis. Mitochondria import more than 1000 different proteins from the cytosol. It is unknown if the mitochondrial protein import machinery is connected to the cell division cycle. We found that the cyclin-dependent kinase Cdk1 stimulated assembly of the main mitochondrial entry gate, the translocase of the outer membrane (TOM), in mitosis. The molecular mechanism involved phosphorylation of the cytosolic precursor of Tom6 by cyclin Clb3-activated Cdk1, leading to enhanced import of Tom6 into mitochondria. Tom6 phosphorylation promoted assembly of the protein import channel Tom40 and import of fusion proteins, thus stimulating the respiratory activity of mitochondria in mitosis. Tom6 phosphorylation provides a direct means for regulating mitochondrial biogenesis and activity in a cell cycle-specific manner.
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