ANALYSIS OF BOVINE SELENOPROTEIN P-LIKE PROTEIN GENE AND AVAILABILITYOF METAL-RESPONSIVE ELEMENT (MRE) LOCATED IN ITS PROMOTER

Selenoprotein P-like protein, similar to selenoprotein P, uses multipl e TGAs for incorporation of selenocysteines but not as stop codons. It is also characterized by having a His-Pro-rich domain and a regionall y differential expression pattern. Hence, in addition to selenium meta bolism, this protein is considered to have a developmental function. I n the present study, the structure of the selenoprotein P-like protein gene was analyzed. The gene consisted of five exons, and the 5'-flank ing region contained a TATA box, TCF-1-CS, bHLH-CS, gamma-IRE-CS, c-My b-CS, C/EBP-CS, HNF-5-CS, MRE2-CS, etc. The presence of motifs like TC F-1-CS, c-Myb-CS, etc. supports the suggestion that this protein is in volved in cellular maturation. Since the presence of MRE2-CS suggests that this protein is related to the antidote effect of selenium agains t heavy metal intoxication, the availability of this motif was examine d using bovine kidney cell lines, CKT-1 and MDBK. Metallothionein mRNA markedly increased 6 h after administration of 10(-6) CdCl2 and ZnCl2 in both cell lines. No significant alteration was observed in selenop rotein P-like protein mRNA, whereas its basal expression was high, ind icating that this protein is constitutively expressed. Thus, it is sti ll possible that this protein acts as an antidote, even though it is n ot inducible by heavy metals. (C) 1997 Elsevier Science B.V.