Isolation and characterization of cDNA encoding rat heart type acetyl-CoA carboxylase.

We isolated and characterized cDNA clones encoding the entire open reading frame (ORF) of a protein consisting of 2456 amino acids with a molecular mass of 276069 Da from rat heart. As the deduced amino acid sequence showed 85% homology with that of human type 2 acetyl-CoA carboxylase (ACC2), we concluded that the cDNA clones encode rat heart type ACC2. Using the identified cDNA fragments and the reported cDNA fragment of rat type 1 ACC (ACC1), we determined the steady state transcript levels of ACC1 and ACC2 in various rat tissues quantitatively by Northern blot analysis. The transcript level of ACC2 was high in heart, skeletal muscle and brown adipose tissue, which require high energy and mainly metabolize fatty acids, whereas that of ACC1 was high in white adipose tissue, which stores fatty acids.