title: Arginine kinases from the marine feather star Tropiometra afra macrodiscus: The first finding of a prenylation signal sequence in metazoan phosphagen kinases.
abstract: Two arginine kinase cDNAs (AK1 and AK2) were isolated from the marine feather star Tropiometra afra macrodiscus, and the gene structure (exon/intron organization) of AK1 was determined. The cDNA-derived amino acid sequences and the exon/intron organization of the Tropiometra AK1 gene were homologous to those of a human creatine kinase (CK) as well as the AK of the sea cucumber Stichopus. Phylogenetic analysis also supports the close relationship between human CKs and echinoderm AKs, indicating that the latter AKs evolved from an ancestral CK gene. We observed that the Tropiometra AK1 gene has a novel C-terminal extension (approximately 50 amino acid residues) encoded by a unique exon. Moreover, a typical prenylation signal sequence (CSLL) was found at the C-terminal end of this extension, suggesting that AK1 is anchored to a membrane. AK2 had no such C-terminal extension. This is the first finding of a prenylation signal in metazoan phosphagen kinases. Recombinant Tropiometra AK1 and AK2 enzymes were successfully expressed in Escherichia coli, and their kinetic constants were determined. Both enzymes showed activity comparable to that of typical invertebrate AKs.
authors.affiliation: Laboratory of Biochemistry, Faculty of Science, Kochi University, Kochi 780-8520, Japan.
authors.forename: Kaai
authors.initials: K
authors.lastname: Chouno
authors.affiliation: Laboratory of Biochemistry, Faculty of Science, Kochi University, Kochi 780-8520, Japan.
authors.forename: Daichi
authors.initials: D
authors.lastname: Yano
authors.affiliation: Laboratory of Biochemistry, Faculty of Science, Kochi University, Kochi 780-8520, Japan.
authors.forename: Kouji
authors.initials: K
authors.lastname: Uda
authors.affiliation: Department of Zoology, National Museum of Nature and Science, Tsukuba 305-0005, Japan.
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Fujita
authors.affiliation: Faculty of Geo-environment Science, Rissho University, Magechi 1700, Kumagaya 360-0194, Japan.
authors.forename: Nozomu
authors.initials: N
authors.lastname: Iwasaki
authors.affiliation: Laboratory of Biochemistry, Faculty of Science, Kochi University, Kochi 780-8520, Japan. Electronic address: suzuki@kochi-u.ac.jp.
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Suzuki
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001122:Arginine Kinase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D004447:Echinodermata / Q000201:enzymology*; D005091:Exons / Q000235:genetics; D006801:Humans; D007438:Introns / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D017368:Protein Prenylation; D021382:Protein Sorting Signals; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid
chemical_list: D021382:Protein Sorting Signals; D001122:Arginine Kinase
keywords: Arginine kinase; Phosphagen kinase; Prenylation; Tropiometra afra