Kim K H, Tae H J
Department of Biochemistry, Purdue University, West Lafayette, IN 47907.
J Nutr. 1994 Aug;124(8 Suppl):1273S-1283S. doi: 10.1093/jn/124.suppl_8.1273S.
Acetyl-CoA carboxylase is the rate-limiting enzyme in the biogenesis of long chain fatty acids. There is a single copy of the gene for acetyl-CoA carboxylase per haploid chromosome set. The gene contains two promoters whose primary transcripts are differentially spliced resulting in multiple forms of acetyl-CoA carboxylase mRNA. These mRNA species are different in the 5'-untranslated region, but contain the same coding region. Generation of different forms of the mRNA is tissue specific and controlled by physiological conditions. Two promoters contain an extensive array of cis-elements that perceive changes in the cellular environment signalling repression and induction of long chain fatty acid synthesis. The ability of the gene to respond to various lipogenic signals and the presence of the same coding sequence in all acetyl-CoA carboxylase mRNA species suggest that the biosynthesis of fatty acids required for multiple functions in the cells is primarily regulated at the gene level.
乙酰辅酶A羧化酶是长链脂肪酸生物合成中的限速酶。每个单倍体染色体组中乙酰辅酶A羧化酶基因只有一个拷贝。该基因包含两个启动子，其初级转录本经过差异剪接，产生多种形式的乙酰辅酶A羧化酶mRNA。这些mRNA种类在5'-非翻译区不同，但包含相同的编码区。不同形式mRNA的产生具有组织特异性，并受生理条件控制。两个启动子含有大量顺式元件，可感知细胞环境信号的变化，从而抑制和诱导长链脂肪酸合成。该基因对各种生脂信号作出反应的能力以及所有乙酰辅酶A羧化酶mRNA种类中相同编码序列的存在表明，细胞中多种功能所需脂肪酸的生物合成主要在基因水平上受到调控。
