Hämäläinen L, Oikarinen J, Kivirikko K I
J Biol Chem. 1985 Jan 25;260(2):720-5.
The metabolism of type I procollagen mRNAs was studied in confluent cultures of human skin fibroblasts using the recombinant plasmids Hf677 and Hf32, which contain DNA sequences complementary to human pro-alpha 1(I) and pro-alpha 2(I) mRNAs, respectively. The ratio for the amount of pro-alpha 1(I) mRNAs to pro-alpha 2(I) mRNAs was 2.06:1. These mRNAs were labeled during in vitro transcription of isolated nuclei in the ratio 2.16:1 and during a pulse in cellulo in the ratio 1.96:1, suggesting that the two species are synthesized in the ratio 2:1. No significant differences were found in the rates of degradation, the half-lives of the pro-alpha 1(I) and pro-alpha 2(I) mRNAs being 9.2 and 8.4 h, respectively. Addition of 10 microM cortisol to the growth medium reduced the amounts of the type I procollagen mRNAs by half in 6 h, leaving their ratio unaltered. Incubation of the cells with cortisol had only minor effects on the subsequent synthesis of the mRNAs in isolated nuclei in vitro, whereas the degradation rates in cellulo were distinctly accelerated.
利用重组质粒Hf677和Hf32，在人皮肤成纤维细胞的汇合培养物中研究了I型前胶原mRNA的代谢，这两种质粒分别含有与人前α1（I）和前α2（I）mRNA互补的DNA序列。前α1（I）mRNA与前α2（I）mRNA的量之比为2.06:1。这些mRNA在分离细胞核的体外转录过程中以2.16:1的比例被标记，在细胞内脉冲标记过程中以1.96:1的比例被标记，这表明这两种mRNA以2:1的比例合成。在降解速率方面未发现显著差异，前α1（I）和前α2（I）mRNA的半衰期分别为9.2小时和8.4小时。向生长培养基中添加10μM皮质醇在6小时内使I型前胶原mRNA的量减少了一半，但其比例不变。用皮质醇处理细胞对随后分离细胞核在体外的mRNA合成只有轻微影响，而细胞内的降解速率明显加快。
