Cloning of hypoxia-inducible factor 1 alpha cDNA from chick embryonic ventricular myocytes

Hypoxia-inducible factor 1 (HIF-1) is composed of HIF-1 alpha and arylhydoc arbon nuclear receptor translocator (ARNT), which belong to the basic-helix -loop-helix-Per/ARNT/Sim bHLH-PAS) family of transcription factors. HLF pla ys key roles in oxygen homeostasis and embryonic cardiovascular development . In this study, we have cloned cDNAs encoding the chick HIF-1 alpha from c ultured embryonic ventricular myocytes (CEVM) and then examined its express ion in various embryonic tissues. The deduced amino acid sequence of the ch ick HIF-1 alpha cDNA showed 79% identity with that of the human HIF-1 alpha cDNA. In contrast, sequence homology between the chick HIF-1 alpha and end othelial PAS protein 1 (EPAS1), another member of the bHLH-PAS proteins, wa s only low (49%). HIF-1 alpha mRNA was expressed abundantly in CEVM., but s carcely in the liver, which was quite different from expression pattern of EPAS1 mRNA. These data suggest that HIF-1 alpha may be involved in embryoni c cardiovascular development. HIF-1 alpha and EPAS1 may play distinct roles during developmental stages. (C) 2001 Academic Press.