Molecular cloning and stress-induced expression of paralichthys olivaceus heme-regulated initiation factor 2 α kinase

• Published in: Developmental & Comparative Immunology 2006, Vol.30 (11), p.1047-1059
• Main Authors: Zhu, Rong, Zhang, Yi-Bing, Chen, Yu-Dong, Dong, Cai-Wen, Zhang, Fu-Tie, Zhang, Qi-Ya, Gui, Jian-Fang
• Format: Article
• Language: English
• Subjects: Ctenopharyngodon idella; Flounder (paralichthys olivaceus) embryonic cells (FEC); Grass carp haemorrhagic virus (GCHV); Heme-regulated initiation factor 2 α kinase (HRI); Inductive expression; Paralichthys olivaceus; Pleuronectiformes; Stress responses
• ISSN: 0145-305X; 1879-0089; 1365-2567
• DOI: 10.1016/j.dci.2006.02.001

The heme-regulated initiation factor 2 α kinase (HRI) is acknowledged to play an important role in translational shutoff in reticulocytes in response to various cellular stresses. In this study, we report its homologous cDNA cloning and characterization from cultured flounder embryonic cells (FEC) after treatment with UV-inactivated grass carp haemorrhagic virus (GCHV). The full-length cDNA of Paralichthys olivaceus HRI homologue ( PoHRI) has 2391 bp and encodes a protein of 651 amino acids. The putative PoHRI protein exhibits high identity with all members of eIF2 α kinase family. It contains 12 catalytic subdomains located within the C-terminus of all Ser/Thr protein kinases, a unique kinase insertion of 136 amino acids between subdomains IV and V, and a relatively conserved N-terminal domain (NTD). Upon heat shock, virus infection or Poly I:C treatment, PoHRI mRNA and protein are significantly upregulated in FEC cells but show different expression patterns in response to different stresses. In healthy flounders, PoHRI displays a wide tissue distribution at both the mRNA and protein levels. These results indicate that PoHRI is a ubiquitous eIF2 α kinase and might play an important role in translational control over nonheme producing FEC cells under different stresses.