RESUMO
CCAAT/enhancer-binding protein alpha (C/EBPα) is an essential transcription factor, regulating the differentiation of adipocytes. We cloned the complete open reading frame of C/EBPα gene of Qinchuan cattle and analyzed its protein structures and expression profile in 15 tissues via DNA cloning, sequencing and RT-PCR. Analysis of the putative protein sequences revealed that C/EBPα consists of alpha helices, random coils and a few extended strands. A significant transmembrane structure was observed in amino acid region 233 to 252. A basic leucine zipper domain was also found in amino acid region 277 to 340, which is characteristic of C/EBPs. Homologous comparison with various species indicated that the C/EBPα gene of Qinchuan cattle shares 97, 95, 94, 94, and 93% similarity in amino acid sequences with Sus scrofa, Homo sapiens, Rattus norvegicus, Oryctolagus cuniculus, and Mus musculus, respectively, implying strong sequence conservation of C/EBPα during evolution. RT-PCR revealed that the mRNA expression level of bovine C/EBPα gene in subcutaneous fat is much higher than that in the other 14 tissues, and the relative quantity in fat tissue increases with cattle age.
