title: COMMD6 from amphioxus Branchiostoma belcheri (BbCOMMD6) interacts with creatine kinase and inhibits its activity.
abstract: COMM domain-containing proteins are a group of recently discovered proteins; their biochemical characterization remains much limited. Here we demonstrate that a cDNA encoding Branchiostoma belcheri COMMD6, designated BbCOMMD6, codes for a protein of 203 amino acids, with a COMM domain at its C-terminal region and an extended N-terminal portion. BbCOMMD6 is mainly present in the cytosol. In contrast to COMMD1, the presence of Cu(II) cannot enhance recombinant BbCOMMD6 dimer formation. Both the pull-down and reverse pull-down assays reveal that BbCOMMD6 interacts with the creatine kinase (CK), an essential enzyme involved in energy metabolism, forming a heterodimer BbCOMMD6-CK. The enzymatic activity assays show that CK activities are inhibited by BbCOMMD6 in a dose-dependent manner. All these data suggest that BbCOMMD6 is involved in energy transduction, via binding to CK and inhibiting activities of CK, and offer first clues to its role as a regulator of CK activities.
authors.affiliation: Department of Marine Biology, Ocean University of China, Qingdao 266003, China.
authors.forename: Peipei
authors.initials: P
authors.lastname: Li
authors.forename: Shicui
authors.initials: S
authors.lastname: Zhang
authors.forename: Chunxin
authors.initials: C
authors.lastname: Fan
mesh_terms: D000818:Animals; D001483:Base Sequence; D002352:Carrier Proteins / Q000378:metabolism*; D002458:Cell Fractionation; D002816:Chordata, Nonvertebrate / Q000235:genetics / Q000378:metabolism; D003001:Cloning, Molecular; D003300:Copper / Q000737:chemistry / Q000378:metabolism*; D003402:Creatine Kinase / Q000037:antagonists & inhibitors*; D004734:Energy Metabolism; D004791:Enzyme Inhibitors / Q000378:metabolism*; D008969:Molecular Sequence Data; D011485:Protein Binding; D055503:Protein Multimerization; D021381:Protein Transport; D011994:Recombinant Proteins / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; D004791:Enzyme Inhibitors; D011994:Recombinant Proteins; D003300:Copper; D003402:Creatine Kinase