胰岛素和地塞米松刺激中国仓鼠卵巢细胞中一个扩增的谷氨酰胺合成酶基因的转录。

Insulin and dexamethasone stimulate transcription of an amplified glutamine synthetase gene in Chinese hamster ovary cells.

作者信息

Bhandari B, Wilson R H, Miller R E

机构信息

Department of Medicine, Veterans Administration Medical Center, Cleveland, Ohio 44106.

出版信息

Mol Endocrinol. 1987 Jun;1(6):403-7. doi: 10.1210/mend-1-6-403.

DOI:10.1210/mend-1-6-403

PMID:2908559

Abstract

We have investigated the regulation of glutamine synthetase (GS) mRNA synthesis in Chinese hamster ovary cell mutants which overproduce GS and contain an amplified GS gene. Specific mRNA synthesis was analyzed by measuring elongation of transcripts in isolated nuclei. Transcription was assayed by hybridization of newly synthesized [32P]RNA to a genomic GS clone. Nuclear transcript elongation was inhibited more than 90% by alpha-amanitin. The relative rates of GS mRNA synthesis in nuclei from cells incubated for 2 days with no additions, insulin, dexamethasone, or (Bu)2cAMP are 186, 419, 375, and 227 ppm, respectively. The insulin- and dexamethasone-mediated increases in GS transcription rate (2-fold) were associated with 3.7- and 5.8-fold increases in GS mRNA abundance. By contrast, alpha-tubulin gene transcription was not altered by insulin or dexamethasone; however, it was decreased by (Bu)2cAMP.

摘要

我们研究了中国仓鼠卵巢细胞突变体中谷氨酰胺合成酶（GS）mRNA合成的调控，这些突变体过量产生GS并含有一个扩增的GS基因。通过测量分离细胞核中转录本的延伸来分析特异性mRNA合成。通过将新合成的[32P]RNA与基因组GS克隆杂交来测定转录。α-鹅膏蕈碱可使细胞核转录延伸受到90%以上的抑制。在未添加任何物质、添加胰岛素、地塞米松或（Bu）2cAMP的情况下培养2天的细胞中，细胞核中GS mRNA合成的相对速率分别为186、419、375和227 ppm。胰岛素和地塞米松介导的GS转录速率增加（2倍）与GS mRNA丰度增加3.7倍和5.8倍相关。相比之下，α-微管蛋白基因转录不受胰岛素或地塞米松的影响；然而，它会被（Bu）2cAMP降低。