摘要
Artemia embryos can endure extreme temperature, long-term anoxia, desiccation and other wide variety of stressful conditions. How the embryos survive these stresses is a very interesting and unsolved subject. To solve this question we analyzed the nucleotide and deduced protein sequence for Hsp26, a molecular chaperone specific to Artemia embryo development, cDNAs of Hsp26 were sequenced from eight Artemia species and deduced Hsp26 amino acid sequences were analyzed. Computer-assisted analysis indicated that the 5＇-untranslated region and all the 3 introns contain many putative cis-acting elements for Hsp26 gene expression during development, including heat shock elements （HSEs）, Dfd, dl, CF2-II, Hb and AP-1 binding sites. Secondary structure of the Hsp26 3＇-untranslated terminator contains the basic structure basis for transcriptional termination. Hsp26 shares sequence similarity with sHSPs （small heat shock protein） from other organisms. The physico-chemical properties of the deduced protein, such as theoretical molecular weight, protein extinction coefficient, isoelectric point and antigenic sites were also obtained. One seven-peptide nuclear localization signals （NLS） ＂PFRRRMM＂ was found, which suggested that the Hsp26 protein was hypothesized to be located inside the nucleus. The numbers of phosphorylation sites of serine, threonine and tyrosine and kinase specific phosphorylation sites are also located in Hsp26 protein sequence. These studies will help us achieve a better understanding of Hsp26 and broad implications for sHSPs function in crustacean embryo development.
Artemia embryos can endure extreme temperature, long-term anoxia, desiccation and other wide variety of stressful conditions. How the embryos survive these stresses is a very interesting and unsolved subject. To solve this question we analyzed the nucleotide and deduced protein sequence for Hsp26, a molecular chaperone specific to Artemia embryo development, cDNAs of Hsp26 were sequenced from eight Artemia species and deduced Hsp26 amino acid sequences were analyzed. Computer-assisted analysis indicated that the 5＇-untranslated region and all the 3 introns contain many putative cis-acting elements for Hsp26 gene expression during development, including heat shock elements （HSEs）, Dfd, dl, CF2-II, Hb and AP-1 binding sites. Secondary structure of the Hsp26 3＇-untranslated terminator contains the basic structure basis for transcriptional termination. Hsp26 shares sequence similarity with sHSPs （small heat shock protein） from other organisms. The physico-chemical properties of the deduced protein, such as theoretical molecular weight, protein extinction coefficient, isoelectric point and antigenic sites were also obtained. One seven-peptide nuclear localization signals （NLS） ＂PFRRRMM＂ was found, which suggested that the Hsp26 protein was hypothesized to be located inside the nucleus. The numbers of phosphorylation sites of serine, threonine and tyrosine and kinase specific phosphorylation sites are also located in Hsp26 protein sequence. These studies will help us achieve a better understanding of Hsp26 and broad implications for sHSPs function in crustacean embryo development.
