Expression of the human atypical kinase ADCK3 rescues coenzyme Q biosynthesis and phosphorylation of Coq polypeptides in yeast coq8 mutants

Biochim Biophys Acta. 2011 May;1811(5):348-60. doi: 10.1016/j.bbalip.2011.01.009. Epub 2011 Feb 4.

Abstract

Coenzyme Q (ubiquinone or Q) is a lipid electron and proton carrier in the electron transport chain. In yeast Saccharomyces cerevisiae eleven genes, designated COQ1 through COQ9, YAH1 and ARH1, have been identified as being required for Q biosynthesis. One of these genes, COQ8 (ABC1), encodes an atypical protein kinase, containing six (I, II, III, VIB, VII, and VIII) of the twelve motifs characteristically present in canonical protein kinases. Here we characterize seven distinct Q-less coq8 yeast mutants and show that unlike the coq8 null mutant, each maintained normal steady-state levels of the Coq8 polypeptide. The phosphorylation states of Coq polypeptides were determined with two-dimensional gel analyses. Coq3p, Coq5p, and Coq7p were phosphorylated in a Coq8p-dependent manner. Expression of a human homolog of Coq8p, ADCK3(CABC1) bearing an amino-terminal yeast mitochondrial leader sequence, rescued growth of yeast coq8 mutants on medium containing a nonfermentable carbon source and partially restored biosynthesis of Q(6). The phosphorylation state of several of the yeast Coq polypeptides was also rescued, indicating a profound conservation of yeast Coq8p and human ADCK3 protein kinase function in Q biosynthesis.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Humans
  • Mitochondria / metabolism
  • Mitochondria / ultrastructure
  • Mitochondrial Proteins / genetics
  • Mitochondrial Proteins / metabolism*
  • Molecular Sequence Data
  • Mutation
  • Peptides / genetics
  • Peptides / metabolism*
  • Phosphorylation
  • Saccharomyces cerevisiae / enzymology*
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism*
  • Sequence Alignment
  • Ubiquinone / biosynthesis*
  • Ubiquinone / genetics
  • Ubiquinone / metabolism

Substances

  • ADCK3 protein, human
  • COQ8 protein, S cerevisiae
  • Mitochondrial Proteins
  • Peptides
  • Saccharomyces cerevisiae Proteins
  • Ubiquinone
  • ubiquinone 8