title: Characterization and expression analysis of EF hand domain-containing calcium-regulatory gene from disk abalone: calcium homeostasis and its role in immunity.
abstract: The complete amino acid sequence of a calcium-regulatory gene (denoted as Ab-CaReg I) was identified from the disk abalone Haliotis discus discus cDNA library. The Ab-CaReg I is composed of 176 amino acids and the calculated molecular mass and isoelectric point were 20 and 4.2, respectively. The sequence homology of Ab-CaReg I was 28-30 and 18-27% of known calmodulin and troponin C, respectively. Four characteristic calcium-binding EF hand motifs with some modifications at conserved positions of known homologous calmodulin genes were observed in the sequence. The tissue-specific transcription analysis and variation of mRNA transcription level of Ab-CaReg I in gills and mantle after animals were immersed in seawater containing 2000 ppm CaCl(2) was quantified by SYBR Green real-time PCR analysis. Transcription variation of Ab-CaReg I in hemocytes and gills followed by bacteria challenge (Vibrio alginolyticus, Vibrio parahaemolyticus and Listeria monocytogenes) was used to investigate Ab-CaReg I in immune responses. Transcripts of Ab-CaReg I mRNA were mainly detected in hemocytes, mantle, muscle, gills, digestive tract and hepatopancreas with highest expression in hemocytes. The CaCl(2) immersion significantly altered the Ab-CaReg I mRNA transcription level by 3 h, compared to animals in normal seawater (control). The mRNA expression of Ab-CaReg I in gills and hemocytes was upregulated significantly to 11-fold and 4-fold in 3 h compared to control (uninfected), respectively, in bacteria-challenged abalones. The results suggest that Ab-CaReg I could be effectively induced to maintain internal Ca(2+) homeostasis of the animal due to influx of Ca(2+) in the cells by external stimuli such as a high dose of Ca(2+) and pathogens like bacteria.
authors.affiliation: Department of Marine Life Sciences, School of Marine Biomedical Science, Jeju National University, Jeju Special Self-Governing Province 690-756, Republic of Korea.
authors.forename: Chamilani
authors.initials: C
authors.lastname: Nikapitiya
authors.forename: Mahanama
authors.initials: M
authors.lastname: De Zoysa
authors.forename: Ilson
authors.initials: I
authors.lastname: Whang
authors.forename: Se-Jae
authors.initials: SJ
authors.lastname: Kim
authors.forename: Cheol Young
authors.initials: CY
authors.lastname: Choi
authors.forename: Jae-Seong
authors.initials: JS
authors.lastname: Lee
authors.forename: Jehee
authors.initials: J
authors.lastname: Lee
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D018407:Bacterial Physiological Phenomena / Q000276:immunology; D001483:Base Sequence; D002118:Calcium / Q000378:metabolism*; D020832:EF Hand Motifs / Q000235:genetics* / Q000276:immunology*; D049851:Gastropoda / Q000235:genetics* / Q000276:immunology* / Q000382:microbiology; D005786:Gene Expression Regulation; D006706:Homeostasis / Q000235:genetics / Q000276:immunology; D008969:Molecular Sequence Data; D010802:Phylogeny; D016415:Sequence Alignment
chemical_list: D002118:Calcium