Characterisation of an N-terminal variant of acetyl-CoA carboxylase-alpha: expression in human tissues and evolutionary aspects.

mRNA encoding a variant acetyl-CoA carboxylase (ACC)-alpha isozyme, transcribed from a downstream promoter, PIII, was detected in human tissues. Such exon 5A-containing transcripts (E5A-mRNA) encode ACC-alpha with a distinct N-terminus, with 15/17 residues identical to those encoded by the ovine mRNA. In the current study we used antisera directed against the E5A N-terminus to verify that ovine E5A translates are present in tissues consistent with the distribution of E5A-mRNA.

Induction of transcripts derived from promoter III of the acetyl-CoA carboxylase-alpha gene in mammary gland is associated with recruitment of SREBP-1 to a region of the proximal promoter defined by a DNase I hypersensitive site.

ACC-alpha (acetyl-CoA carboxylase-alpha), a key regulator of fatty-acid metabolism, is encoded by mRNAs transcribed from three promoters, PI, PII and PIII, in the ovine genome. Enhanced expression of transcripts encoded by PIII in mammary gland during lactation is associated with alterations in chromatin structure that result in the detection of two DNase I hypersensitive sites, upstream of the start site. The most proximal site, located between -190 and -10, is characterized by the presence of an inverted-CCAAT box, C2 at -167, and E-boxes, E1 and E2, at -151 and -46.