| First Author | van der Leij FR | Year | 2002 |
| Journal | J Biol Chem | Volume | 277 |
| Issue | 30 | Pages | 26994-7005 |
| PubMed ID | 12015320 | Mgi Jnum | J:78012 |
| Mgi Id | MGI:2183100 | Doi | 10.1074/jbc.M203189200 |
| Citation | van der Leij FR, et al. (2002) Structural and functional genomics of the CPT1B gene for muscle-type carnitine palmitoyltransferase I in mammals. J Biol Chem 277(30):26994-7005 |
| abstractText | Muscle-type carnitine palmitoyltransferase I (M-CPT I) is a key enzyme in the control of beta-oxidation of long-chain fatty acids in the heart and skeletal muscle. Because knowledge of the mammalian genes encoding M-CPT I may aid in studies of disturbed energy metabolism, we obtained new genomic and cDNA data for M-CPT I for the human, mouse, rat, and sheep. The introns of these compact genes are 80% (mouse versus rat) and 60% (mouse versus human) identical. Sheep and goat, but not cow, pig, rodent, or human promoter sequences contain a short interspersed repeated sequence (SINE) upstream of highly conserved regulatory elements. These elements constitute two promoters in humans, sheep, and mice, and, contrary to previous reports, there is a second promoter in rats as well. Thus, the transcriptional organization of these genes is more uniform than previously supposed, with interspecies differences in the 5'-ends of the mRNAs reflecting differences in splicing; only in humans extensive splicing and splice variation is found in the 5'- and 3'-untranslated regions. In the mouse, intron retention was detected in heart, muscle, and testes and may indicate an additional mechanism of regulation of M-CPT I expression. Splice variation in the coding region was previously proposed to lead to expression of CPT I enzymes with altered malonyl-CoA sensitivity (Yu, G. S., Lu, Y. C., and Gulick, T. (1998) Biochem. J. 334, 225-231). However, when expressed in the yeast Pichia pastoris, none of three earlier described splice variants had CPT I activity. Therefore, the involvement of splice variation of M-CPT I in the modulation of malonyl-CoA inhibition of fatty acid oxidation may be less relevant than hitherto assumed. |
