Identification of Wap65, a human homologue of hemopexin as a copper-inducible gene in swordtail fish, Xiphophorus helleri.
Copper is one of the major heavy metal pollutants found in the aquatic environment. Therefore, it is important for determining the genes that play a key role in copper metabolism in aquatic organisms. This study, thus, aimed to identify a new copper-inducible gene in swordtail fish, Xiphophorus helleri. Using ACP-based RT-PCR coupled with RLM-RACE, we cloned Wap65, a mammalian homologue of hemopexin gene. The gene exhibits high identity at amino acid levels with the Wap65 gene of other fish species (42-68%) and mammalian hemopexin gene (35-37%). In addition, ten cysteine and two histidine residues are conserved in the swordtail fish Wap65 gene. These cysteine residues are vital for structural integrity, and histidine residues provide high binding affinity towards heme. As revealed by RT-PCR, the gene was upregulated in swordtail fish that were exposed to copper in a dose- and time-dependent manner. Therefore, the identification of Wap65, a mammalian homologue of hemopexin, as a new copper-inducible gene will provide greater insight into the role of this gene in copper metabolism.
Aliza
Dwinna
D
School of Biological Sciences, Universiti Sains Malaysia, 11800, Penang, Malaysia.
Ismail
Ida Shazrina
IS
Kuah
Meng-Kiat
MK
Shu-Chien
Alexander Chong
AC
Tengku Muhammad
Tengku Sifzizul
TS
D000595:Amino Acid Sequence; D000818:Animals; D003300:Copper / Q000494:pharmacology*; D029941:Fish Proteins / Q000737:chemistry / Q000235:genetics*; D005786:Gene Expression Regulation / Q000187:drug effects*; D006466:Hemopexin / Q000737:chemistry / Q000235:genetics*; D006801:Humans; D007695:Killifishes / Q000235:genetics*; D008969:Molecular Sequence Data; D016415:Sequence Alignment
D029941:Fish Proteins; D003300:Copper; D006466:Hemopexin