Effects of anti-PM-Scl 100 (Rrp6p exonuclease) antibodies on prenucleolar body dynamics at the end of mitosis
Effects of anti-PM-Scl 100 (Rrp6p exonuclease) antibodies on prenucleolar body dynamics at the end of mitosis
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DOI：
10.1006/excr.1999.4578
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发表时间：
1999-09-15
影响因子：
3.7
通讯作者：
Hernandez-Verdun, D
中科院分区：
文献类型：
--
作者：
Fomproix, N;Hernandez-Verdun, D
核仁前小体(PNBs)是过渡有丝分裂间期核仁的一种暂时性结构，是核仁的组成部分。PNBs的组装及其途径尚不清楚。为了更好地了解这些事件，我们将含有PNB的PM-SCL100蛋白与其他PNB蛋白的行为进行了比较。之所以选择这种核仁蛋白，是因为它的酵母同系物Rrp6p外切核酸酶[1]，已知参与了5.8 S rRNA(核糖体核糖核酸)加工的后期事件。核仁蛋白在不同类型的PNBs中分布不均。PM-SCL 100主要与蛋白质B23共定位，含有PM-SCL-100的PNBs随后被移位到核仁，而不是含有纤维蛋白的PNBs。在有丝分裂期间微量注射针对PM-SD 100的抗体可抑制PM-SCL 100对核仁的靶向。然而，在G1期早期，纤维蛋白和蛋白B23仍参与核仁组装。我们得出结论，存在不同种类的PNBs，它们向核仁的移位遵循有序动力学。有趣的是，参与加工后期步骤的蛋白质，如PM-SD 100，被转移到很晚，这表明它们在共转录上与rRNA前体没有关联。(C)1999年学术出版社。
Prenucleolar bodies (PNBs) are transitory structures which serve as building blocks for nucleoli at the transition mitosis/interphase. The assembly of PNBs and their pathway are not clearly understood. To better understand these events, the behavior of the PNB-containing PM-Scl 100 protein was compared with that of other PNB proteins. This nucleolar protein was chosen because its yeast homologue, Rrp6p exonuclease [1], is known to participate in late events in 5.8 S rRNA (ribosomal RNA) processing. There was a heterogeneous distribution of nucleolar proteins in different classes of PNBs. Tbe PM-Scl 100 colocalized predominantly with protein B23, The PM-Scl-100-containing PNBs were translocated at later times to nucleoli as opposed to the fibrillarin-containing PNBs. Microinjections of antibodies directed against PM-Sd 100 during mitosis inhibited targeting of PM-Scl 100 to the nucleolus. However fibrillarin and protein B23 still participated in nucleolar assembly in early G1. We conclude that there are different kinds of PNBs whose translocation to the nucleoli follow ordered kinetics. Interestingly, proteins involved in late steps of processing as PM-Sd 100 are translocated late, suggesting that they are not cotranscriptionally associated with the rRNA precursors. (C) 1999 Academic Press.