Wang L, Brady P S, Brady L J
Department of Food Science and Nutrition, University of Minnesota, St. Paul 55108.
Biochem J. 1989 Nov 1;263(3):703-8. doi: 10.1042/bj2630703.
Regulation of the 68 kDa carnitine palmitoyltransferase (CPT) synthesis by (chlorophenylthio) cyclic AMP (cAMP) and insulin was studied in H4IIE cells in culture. Addition of 0.1 mM- or 1.0 mM-(chlorophenylthio) cAMP induced CPT mRNA and rate of transcription 2-4-fold by 15 min, reaching a plateau at 4-6-fold by 30 min. Addition of 5-15 nM-insulin plus 1.0 mM-cAMP suppressed the increases in transcription rate and mRNA levels occurring with cAMP alone. The t1/2 for CPT mRNA was 70-80 min and was not affected by cAMP. The t1/2 for CPT protein was 70 min, and was increased to 240 min in the presence of cAMP. The rate of CPT synthesis was also increased in the presence of cAMP. The data indicate that CPT synthesis is increased by cAMP via induction of transcription and subsequent increase in the CPT mRNA. Insulin acts to depress transcription and CPT mRNA. In addition, cAMP prolongs the t1/2 of CPT.
在培养的H4IIE细胞中研究了（氯苯硫基）环磷酸腺苷（cAMP）和胰岛素对68 kDa肉碱棕榈酰转移酶（CPT）合成的调节作用。添加0.1 mM或1.0 mM的（氯苯硫基）cAMP可在15分钟内使CPT mRNA和转录速率诱导增加2至4倍，在30分钟时达到4至6倍的平台期。添加5至15 nM胰岛素加1.0 mM cAMP可抑制单独使用cAMP时转录速率和mRNA水平的增加。CPT mRNA的半衰期为70至80分钟，不受cAMP影响。CPT蛋白的半衰期为70分钟，在存在cAMP的情况下增加到240分钟。在存在cAMP的情况下，CPT的合成速率也增加。数据表明，cAMP通过诱导转录以及随后CPT mRNA的增加来增加CPT的合成。胰岛素起到抑制转录和CPT mRNA的作用。此外，cAMP延长了CPT的半衰期。
