Characterization of different forms of rat mammary gland acetyl-coenzyme A carboxylase mRNA: analysis of heterogeneity in the 5' end.

Acetyl-coenzyme A carboxylase (ACC; EC 6.4.1.2) catalyzes the rate-limiting reaction in the biogenesis of long-chain fatty acids. We have previously reported the coding sequence of ACC mRNA from the mammary gland of the lactating rat. The existence, in this tissue, of several forms of ACC mRNA with different 5'-untranslated regions has now been established. Two mRNAs constitute the major ACC mRNA species, they differ from one another in the presence or absence of a 61-nucleotide fragment at the center of the 5'-untranslated region. Multiple forms of ACC mRNA might originate through differential splicing of the primary transcript.