Divergent sequences in the 5' region of cDNA suggest alternative splicing as a mechanism for the generation of carnitine acetyltransferases with different subcellular localizations.

We identified two partially overlapping cDNAs containing divergent 5' sequences of human carnitine acetyltransferase (CAT). cDNA lambda SM-1400 extends the sequence of peroxisomal CAT, whereas cDNA lambda SM-1200 creates a new open reading frame encoding a putative mitochondrial leader peptide. An intron is located where sequences diverge, suggesting that mitochondrial, peroxisomal and possibly endoplasmic reticulum CAT mRNAs derive from alternative splicing of the CAT gene.