title: Characterization of the arginine kinase isoforms in Caenorhabditis elegans.
abstract: Phosphagen kinases (PKs) are well-studied enzymes involved in energy homeostasis in a wide range of animal, protozoan, and even some bacterial species. Recent genome efforts have allowed comparative work on the PKs to extend beyond the biochemistry of individual proteins to the comparative cellular physiology and examining of the role of all PK family members in an organism. The sequencing of the Caenorhabditis elegans genome and availability of sophisticated genetic tools within that system affords the opportunity to conduct a detailed physiological analysis of the PKs from a well known invertebrate for comparison with the extensive work conducted on vertebrate systems. As a first step in this effort we have carried out a detailed molecular genetic and biochemical characterization of the PKs in C. elegans. Our results reveal that C. elegans has five PK genes encoding arginine kinases that range in catalytic efficiency (kcat/KM(Arg)) from (3.1±0.6)×10(4) to (9±4)×10(5) M(-1) s(-1). This range is generally within the range seen for arginine kinases from a variety of species. Our molecular genetic and phylogenetic analysis reveals that the gene family has undergone extensive intron loss and gain within the suborder Rhabditina. In addition, within C. elegans we find evidence of gene duplication and loss. The analysis described here for the C. elegans AKs represents one of the most complete biochemical and molecular genetic analysis of a PK family within a genetically tractable invertebrate system and opens up the possibility of conducting detailed physiological comparisons with vertebrate systems using the sophisticated tools available with this model invertebrate system.
authors.affiliation: Program in Biochemistry and Molecular Biology, The College of Wooster, Wooster, OH 44691, United States; Department of Biology, The College of Wooster, Wooster, OH 44691, United States. Electronic address: dfraga@wooster.edu.
authors.forename: Dean
authors.initials: D
authors.lastname: Fraga
authors.affiliation: Program in Biochemistry and Molecular Biology, The College of Wooster, Wooster, OH 44691, United States.
authors.forename: Manish
authors.initials: M
authors.lastname: Aryal
authors.affiliation: Program in Biochemistry and Molecular Biology, The College of Wooster, Wooster, OH 44691, United States.
authors.forename: Joseph E
authors.initials: JE
authors.lastname: Hall
authors.affiliation: Program in Biochemistry and Molecular Biology, The College of Wooster, Wooster, OH 44691, United States.
authors.forename: Evan
authors.initials: E
authors.lastname: Rae
authors.affiliation: Program in Biochemistry and Molecular Biology, The College of Wooster, Wooster, OH 44691, United States; Department of Chemistry, The College of Wooster, Wooster, OH 44691, United States.
authors.forename: Mark
authors.initials: M
authors.lastname: Snider
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001122:Arginine Kinase / Q000737:chemistry* / Q000235:genetics*; D001483:Base Sequence; D017173:Caenorhabditis elegans / Q000201:enzymology* / Q000235:genetics*; D023281:Genomics; D007438:Introns / Q000235:genetics; D007527:Isoenzymes / Q000737:chemistry / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D012689:Sequence Homology, Nucleic Acid
chemical_list: D007527:Isoenzymes; D001122:Arginine Kinase
keywords: Gene duplication; Introns; Nematode; Phosphagen kinase