RESUMO
Apolipoproteins are carrier proteins that bind to lipids to form lipoprotein particles and have been shown to play an important role in lipid metabolism. In this study, a full-length cDNA for apolipoprotein E, named AsapoE, was cloned from the Chinese sturgeon (Acipenser sinensis). This cDNA sequence is 1289 bp in length, and codes for a polypeptide of 274 amino acid residues, which is 45% and 42% identical to that of the rainbow trout and zebrafish, respectively, and 39%, 30%, and 29% identical to frog, mouse, and human respectively. The predicted AsApoE protein has a conserved amphipathic α-helix region with the potential to bind to lipids. RT-PCR analysis reveals that AsapoE is expressed in all tissues examined with a preferential expression in the kidney and liver. During the embryo development stage, AsapoE mRNA is low but still detectable at gastrula stage embryos; then AsapoE mRNAs reach a higher level in muscle contraction stage embryos, this relatively stable expression persists during the following embryogenic stages and declines 1 day after hatching. These results will serve as a basis for comparative studies on vertebrate apoE genes.
