EFFECTS OF ANTI-C23 (NUCLEOLIN) ANTIBODY ON TRANSCRIPTION OF RIBOSOMAL DNA IN CHIRONOMUS SALIVARY-GLAND CELLS
EFFECTS OF ANTI-C23 (NUCLEOLIN) ANTIBODY ON TRANSCRIPTION OF RIBOSOMAL DNA IN CHIRONOMUS SALIVARY-GLAND CELLS
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DOI：
10.1016/0014-4827(88)90397-7
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发表时间：
1988-10-01
影响因子：
3.7
通讯作者：
OLSON, MOJ
中科院分区：
文献类型：
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作者：
EGYHAZI, E;PIGON, A;OLSON, MOJ
蛋白质C23（也称为核仁素或100-kDa核仁蛋白）是参与核糖体生物合成的主要核仁磷蛋白。为研究蛋白质C23对前核糖体RNA（pre-rRNA）合成的影响，将抗C23抗血清显微注射到摇蚊唾液腺细胞核中。转录测定孵育的腺体与32 P-标记的RNA前体，然后通过显微解剖的核仁，RNA提取，和电泳分析。注射抗-C23抗体引起2- 3.5倍的32 P掺入38 S前rRNA的刺激。在注射免疫前血清或用蛋白C23预吸收的抗血清的唾液腺中没有观察到刺激。的刺激作用是选择性的前rRNA的32 P掺入到核仁RNA的刺激缺乏所示。注射抗血清对前体RNA加工产生很小或没有影响，如通过刺激与对照腺体中前体rRNA的32 P标记的中间切割产物的相对量所测量的。当摇蚊唾液腺核的蛋白质提取物进行了探测与抗C23抗体的蛋白质印迹的主要交叉反应物种是一个110 kDa的多肽，其具有类似的蛋白质C23的电泳迁移率。这些结果表明，C23蛋白不仅参与核糖体组装，而且还在调节前核糖体RNA的转录中起作用。
Protein C23 (also called nucleolin or 100-kDa nucleolar protein) is a major nucleolar phosphoprotein involved in ribosome biogenesis. To determine the effects of protein C23 on preribosomal RNA (pre-rRNA) synthesis anti-C23 antiserum was microinjected into nuclei of Chironomus tentans salivary glands. Transcription was measured by incubation of the glands with 32P-labeled RNA precursors followed by microdissection of nucleoli, RNA extraction, and electrophoretic analyses. Injection of the anti-C23 antibody caused a 2- to 3.5-fold stimulation of 32P incorporation into 38 S pre-rRNA. No stimulation was observed in salivary glands injected with preimmune serum or antiserum preabsorbed with protein C23. The stimulatory effect was selective for pre-rRNA as indicated by the lack of stimulation of 32P incorporation into extranucleolar RNA. Injection of the antiserum produced little or no effect on pre-RNA processing as measured by the relative amounts of 32P-labeled intermediate cleavage products of pre-rRNA in stimulated versus control glands. When protein extracts of Chironomus tentans salivary gland nuclei were probed on Western blots with anti-C23 antibody the predominant cross-reacting species was a 110-kDa polypeptide which had an electrophoretic mobility similar to that of protein C23. These results suggest that protein C23 not only is involved in ribosome assembly but also plays a role in regulating the transcription of the preribosomal RNA.