title: Multiple isoforms and an unusual cathodic isoform of creatine kinase from channel catfish (Ictalurus punctatus).
abstract: In vertebrates, the creatine kinase (CK) family consists of two cytosolic and two mitochondrial isoforms. The two cytosolic isoforms are the muscle type (M-CK) and the brain type (B-CK). Here we report multiple CK isoenzymes in the diploid channel catfish (Ictalurus punctatus) with one unusual cathodic isoform that was previously found only in pathological situations in human. The cathodic CK isoform existed only in the channel catfish stomach, ovary, and spleen, but not in any other species analyzed such as tilapia, smallmouth bass, chicken, or rat. Two genes encode the multiple forms of the channel catfish M-CK cDNAs. M-CK1 has three alleles, M-CK1.1, M-CK1.2, and M-CK1.3, while M-CK2 has just one allele as determined by analysis of 17 cDNA clones and by allele-specific PCR. M-CK1 encodes a protein of 381 amino acids and the M-CK2 cDNA encodes a protein of 380 amino acids. The two cDNAs shared an 86% identity and both have the nine diagnostic boxes for cytosolic CKs and thus are of cytosolic origin. The M-CK1 gene was isolated, sequenced, and characterized and its promoter should be useful for transgenic research for muscle-specific expression.
authors.affiliation: The Fish Molecular Genetics and Biotechnology Laboratory, Department of Fisheries and Allied Aquacultures and Program of Cell and Molecular Biosciences, Auburn University, Auburn, AL 36849, USA. zliu@acesag.auburn.edu
authors.forename: Z
authors.initials: Z
authors.lastname: Liu
authors.forename: S
authors.initials: S
authors.lastname: Kim
authors.forename: H
authors.initials: H
authors.lastname: Kucuktas
authors.forename: A
authors.initials: A
authors.lastname: Karsi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003402:Creatine Kinase / Q000235:genetics* / Q000378:metabolism; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D004592:Electrophoresis, Starch Gel; D005260:Female; D005796:Genes / Q000235:genetics; D007059:Ictaluridae / Q000235:genetics*; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid; D014018:Tissue Distribution
chemical_list: D018076:DNA, Complementary; D007527:Isoenzymes; D012333:RNA, Messenger; D003402:Creatine Kinase