MOLECULAR-CLONING, SEQUENCE, AND EXPRESSION PATTERNS OF THE HUMAN GENE ENCODING CCAAT ENHANCER-BINDING-PROTEIN-ALPHA (C/EBP-ALPHA)/

The human gene encoding the transcription factor C/EBP alpha was isola ted from an umbilical cord genomic library screened by low stringency hybridization. Two overlapping clones were characterized by restrictio n enzyme analysis and included 13.2 kb of the C/EBP alpha locus. The e ntire gene and 471 bp of the promoter were sequenced. The human C/EBP alpha gene is 2783 bp long and encodes a 356 amino acid long protein, which is the same in length as for rat C/EBP alpha. Compared to rat C/ EBP alpha, there are two insertions of two amino acids and one deletio n of four. The amino acid similarity between the two proteins is over 92%. The human C/EBP alpha gene was found to be expressed at the highe st levels in placenta. High expression was also found in liver, lung, skeletal muscle, pancreas, small intestine, colon and in peripheral bl ood leukocytes. However, the expression was undetectable or very low i n brain, kidney, thymus, testis and ovary. These results show that the human C/EBP alpha gene is expressed in a tissue restricted manner. (C ) 1995 Academic Press, Inc.