| Autor: |
Y C Lin-Lee, S M Soyal, A Surguchov, S Sanders, W Strobl, W Patsch |
| Jazyk: |
angličtina |
| Rok vydání: |
1995 |
| Předmět: |
|
| Zdroj: |
Journal of Lipid Research, Vol 36, Iss 7, Pp 1586-1594 (1995) |
| Druh dokumentu: |
article |
| ISSN: |
0022-2275 |
| DOI: |
10.1016/S0022-2275(20)39744-3 |
| Popis: |
Chronic administration of thyroid hormone (T3) increases apoA-I gene expression in rat liver by enhancing mRNA maturation, but reduces apoA-I mRNA synthesis to 50% of control. To gain insight into the inverse relation of mRNA maturation and mRNA synthesis, we measured transcription in livers of control and T3-treated rats (50 micrograms/100 g body weight for 7 days) by nuclear run-on assays using overlapping antisense RNA probes encompassing the apoA-I gene. In control rats, after normalization for hybridization efficiency and probe length, the hybridization signals with intron 3 probes were reduced to 45% of those obtained with exon 1 to exon 3 probes (P < 0.01) indicating transcriptional arrest or pausing close to the exon 3-intron 3 border or 450 to 650 nucleotides downstream of the transcription start site. In T3-treated rats, the elongation block was nearly twice as effective, while the rate of transcription initiation was similar to control. In contrast, the distribution of nascent transcripts across the apoA-IV gene was symmetric, and T3-treatment suppressed apoA-IV mRNA synthesis by processes operating in the 5' region such as transcription initiation. Thus, conditional transcript elongation contributes to the regulation of apoA-I gene expression in rat liver. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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