Molecular characterization of hypoxia inducible factor-1 (HIF-1) from the white shrimp Litopenaeus vannamei and tissue-specific expression under hypoxia

Hypoxia inducible factor 1 (HIF-1) is a key transcription factor that regulates a variety of molecular responses to hypoxia. Some marine crustaceans experience changes of oxygen tension in their aquatic environment, but knowledge about the function and expression of HIF-1 is very limited. HIF-1 is a heterodimer composed by alpha and 0 subunits. We report the complete cDNA sequences of HIF-1 alpha and HIF-1 beta from the white shrimp Litopenaeus vannamei. HIF-1 alpha(LvHIF-1 alpha) is 3672 bp and codes for 1050 amino acids, while HIF-1 beta is 2135 bp (LvHIF-1,3) and 608 amino acids. Both, the (x and P subunits have the helix-loop-helix (bHLH) and PAS domains. HIF-1 alpha also has the oxygen dependent degradation (ODD) and the C-terminal transactivation domain (C-TAD), important for regulation in normoxia. Phylogenetic analyses of the proteins indicate separation of invertebrates from vertebrates. Large differences of HIF-1 alpha and HIF-1 beta transcripts abundance were detected in gills, hepatopancreas and muscle under normoxia (6 mg/L dissolved oxygen, DO) and hypoxia (2.5 and 1.5 mg/L DO). HIF-1 alpha was more abundant in gills and HIF-1 P in hepatopancreas. Large changes in response to hypoxia were detected for HIF-1 a in gills, while HIF-1 beta remained fairly constant. Glucose and lactate in hemolymph increased rapidly in hypoxia in all cases and up to 4.7 and 5.0-fold, respectively, in response to 1.5 mg/L DO for 1 h. (C) 2009 Elsevier Inc. All rights reserved.