TITLE:
Phylogenetic Analysis and Taste Cell Expression of Calpain 9 in Catfish (Ictalurus punctatus)
AUTHORS:
Tetsuya Ookura, Eiki Koyama, Anne Hansen, John H. Teeter, Yukio Kawamura, Joseph G. Brand
KEYWORDS:
Gene Evolution, Taste, Novel Type
JOURNAL NAME:
Natural Science,
Vol.7 No.3,
March
13,
2015
ABSTRACT: The calpains, calcium-activated neutral proteases, play important roles in calcium-regulated intra-cellular signal transduction cascades. Here we report the isolation and initial characterization of a cDNA encoding a calpain 9, digestive tract specific calpain, from catfish taste epithelium. This calpain 9 (Ip-CAPN9a) shares 61% identity with human calpain 9. Phylogenetic analysis provides evidence that catfish calpain 9 and the related enzymes from Oncorhynchus mykiss, Danio rerio, Xenopus laevis, Mus musculus, Rattus norvegicus and Homo sapiens make up a distinct clade within the tissue-specific calpain family. Northern blot analysis reveals that Ip-CAPN9a is predominantly expressed in barbell and digestive tract, but not expressed in brain. An antibody against the N-terminal segment of Ip-CAPN9a recognizes cells within the taste buds in catfish barbells.