Molecular cloning, characterization and expression analysis of ubiquitin protein ligase gene (As-ubpl) from Artemia sinica

Ubiquitylation is an important protein post-translational regulation pathway, which is involved in controlling protein degradation, tumor occurrence and cell cycle regulation. E3 ubiquitin protein ligase (UBPL) plays a crucial role of the conjugation of activated ubiquitin to protein substrates and leads to targeting proteins for degradation by the proteasome. We amplified one full-length cDNA of the A. sinica UBPL (As-ubpl) gene by RACE technology. The full-length cDNA of As-ubpl is composed of 2931 bp, with a 2571 bp open reading frame (ORF) that encodes a polypeptide of 856 amino acids with a C2 domain, two domains with two conserved Trp (W) residues (WW) and a homologous to E6-AP Carboxyl Terminus (HECT) domain. The amount of As-ubpl showed from real-time PCR indicates that a high expression levels of As-ubpl at 20 h, 40 h and 3 days of embryo development, with highest expression levels appearing in the larval stage (40 h). Furthermore, As-ubpl transcripts were highly up-regulated under salinity (50‰) and low temperature stress (15 °C). These results indicate that As-ubpl is involved in protein regulation of the postdiapause development and in responses to salinity and low temperature stress.