Evidence for an increase in transcription of specific mRNAs during differentiation of 3T3-L1 preadipocytes.
Evidence for an increase in transcription of specific mRNAs during differentiation of 3T3-L1 preadipocytes.
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DOI：
10.1016/s0021-9258(18)89059-7
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发表时间：
1985-05
期刊：
影响因子：
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通讯作者：
David A. BernlohrS;Mark A. BolanowskiQ;Thomas;Kelly;M. Lane
中科院分区：
文献类型：
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作者：
David A. BernlohrS;Mark A. BolanowskiQ;Thomas;Kelly;M. Lane
3 T3-L1前脂肪细胞在培养中的分化伴随着几种mRNA丰度的改变和许多新的脂肪细胞特异性mRNA的出现。为了研究负责这些变化的过程，将几种特定mRNA的积累动力学与它们各自的核径流转录速率进行比较。果糖-1，6-二磷酸醛缩酶的mRNA和一种未鉴定的4800碱基mRNA在分化过程中丰度仅适度增加（2-4倍）。径流转录从3 T3-L1细胞在分化过程中分离的细胞核显示这些mRNA的转录率很少或没有变化。对于β，α-肌动蛋白和β-微管蛋白mRNA获得了类似的结果，其中没有观察到核径流转录速率的差异，即使这些mRNA的稳态水平伴随分化降低2倍。相反，在脂肪转化过程中，3 T3-L1 P2蛋白（髓磷脂P2蛋白的脂肪细胞同源物）和一种未鉴定的5000碱基mRNA的稳态mRNA水平显著增加（超过20倍）。这些丰度的大幅增加与3 T3-L1前脂肪细胞分化过程中这些mRNA的核径流转录率的显著上升（大于10倍）相关。通过对照非分化3 T3-C2细胞的细胞核检测到这些mRNA的径流转录活性没有变化。这些结果强烈表明，增加的特定转录率是主要负责这些mRNA的积累在前脂肪细胞分化。
Differentiation of 3T3-L1 preadipocytes in culture is accompanied by alterations in the abundance of several mRNAs and by the appearance of many new adipocyte-specific mRNAs. To investigate the processes responsible for these alterations, the kinetics of accumulation of several specific mRNAs were compared with their respective rates of nuclear runoff transcription. The mRNAs for fructose-1,6-bisphosphate aldolase and an unidentified 4800-base mRNA increase in abundance only moderately (2-4-fold) during differentiation. Runoff transcription by nuclei isolated from 3T3-L1 cells during the course of differentiation revealed very little or no change in the rates of transcription of these mRNAs. Similar results were obtained for the beta, alpha-actin and beta-tubulin mRNAs where no difference in nuclear runoff transcription rates were observed even though a 2-fold decrease in the steady-state levels of these mRNAs accompanies differentiation. In contrast, the steady-state levels of mRNAs for 3T3-L1 P2 protein, an adipocyte homologue of myelin P2 protein, and an unidentified 5000-base mRNA increased dramatically (greater than 20-fold) during adipose conversion. These large increases in abundance were correlated with marked rises (greater than 10-fold) in nuclear runoff transcription rates for these mRNAs during differentiation of 3T3-L1 preadipocytes. No change in runoff transcription activity for these mRNAs was detected by nuclei from control nondifferentiating 3T3-C2 cells. These results strongly suggest that an increased rate of specific transcription is primarily responsible for the accumulation of these mRNAs during preadipocyte differentiation.