Nuclear export of signal recognition particle RNA in mammalian cells
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- 作者：Alavian ; Christina N. ; Ritland Politz ; Joan C. ; Lewandowski ; Laura B. ; Powers ; Christine M. ; et. al.
- 关键词：Nucleolus ; RNA traffic
- 刊名：Biochemical and Biophysical Research Communications
- 出版年：2004
- 出版时间：January 9, 2004
- 年：2004
- 卷：313
- 期：2
- 页码：351-355
- 全文大小：193 K
文摘
In mammalian cells the signal recognition particle (SRP) consists of a mg align=center border=0 SRC=/images/glyphs/BQ1.GIF>300 nucleotide RNA and six proteins. Although the molecular structure and functional cycle of the SRP are both very well understood, far less is known about how the SRP is first assembled in the cell. Recent work has suggested that SRP assembly begins in the nucleoli. When NRK (rat fibroblast) cells were treated with leptomycin B (LMB), a specific inhibitor of the CRM1 nuclear export receptor, the level of SRP RNA increased in the nucleoli, as did the level of nucleolar 28S ribosomal RNA. Moreover, when a hamster cell line carrying a temperature-sensitive mutation in the guanine nucleotide exchange factor of the GTPase Ran (Ran-GEF) was shifted to the non-permissive temperature, the nucleolar level of SRP RNA increased. These results indicate that the steady-state concentration of SRP RNA in the nucleolus is sensitive to perturbations in nuclear import/export pathways.