NUCLEOLOGENESIS - U3 SNRNA-CONTAINING PRENUCLEOLAR BODIES MOVE TO SITES OF ACTIVE PRE-RIBOSOMAL-RNA TRANSCRIPTION AFTER MITOSIS
NUCLEOLOGENESIS - U3 SNRNA-CONTAINING PRENUCLEOLAR BODIES MOVE TO SITES OF ACTIVE PRE-RIBOSOMAL-RNA TRANSCRIPTION AFTER MITOSIS
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DOI：
10.1091/mbc.5.9.955
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发表时间：
1994-09-01
影响因子：
3.3
通讯作者：
SPECTOR, DL
中科院分区：
文献类型：
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作者：
JIMENEZGARCIA, LF;SEGURAVALDEZ, MD;SPECTOR, DL
我们研究了 HeLa 细胞和正常大鼠肾细胞在间期和有丝分裂期间 U3 snRNA 和 rRNA 的分布。 U3 snRNA 已知参与前 rRNA 加工，在间期期间在核仁和卷曲体中检测到，而 rRNA 分布在核仁和整个细胞质中。相比之下，在核仁、卷曲体和细胞质中检测到核糖体蛋白 S6。在核发生过程中，在末期末期新形成的核仁中观察到前rRNA，但在核仁前体（PNB）中未观察到，而U3 snRNA在形成核仁和PNB中检测到。与此处报道的 U3 snRNA 定位类似的发现之前已报道过 U3 小核核糖核蛋白纤维蛋白。这些结果表明，参与前 rRNA 加工的成分在有丝分裂末期定位于离散的 PNB。核仁在特定的末期结构域（核仁组织区域）形成，并且含有前 rRNA 加工必需因子的 PNB 被招募到这些 rRNA 转录和加工位点。
We have investigated the distribution of U3 snRNA and rRNA in HeLa cells and normal rat kidney cells during interphase and mitosis. U3 snRNA, known to be involved in pre-rRNA processing, was detected in nucleoli and coiled bodies during interphase, whereas rRNA was distributed in the nucleoli and throughout the cytoplasm. By comparison, ribosomal protein S6 was detected in nucleoli, coiled bodies, and in the cytoplasm. During nucleologenesis, pre-rRNA was observed in newly forming nucleoli during late telophase but not in prenucleolar bodies (PNBs), whereas U3 snRNA was detected in forming nucleoli and PNBs. Similar findings to those reported here for the localization of U3 snRNA have been reported previously for the U3 small nuclear ribonucleoprotein fibrillarin. These results suggest that components involved in pre-rRNA processing localize to discrete PNBs at the end of mitosis. The nucleolus is formed at specific telophase domains (nucleolar organizing regions) and the PNBs, containing factors essential for pre-rRNA processing, are recruited to these sites of rRNA transcription and processing.