Brogna Saverio, Sato Taka Aki, Rosbash Michael
Howard Hughes Medical Institute, Brandeis University, Department of Biology, Waltham, Massachusetts 02454, USA.
Mol Cell. 2002 Jul;10(1):93-104.
It is generally believed that eukaryotic ribosomes first associate with mRNA in the cytoplasm. However, we show with chromosomal immunostaining and in situ hybridization that ribosomal subunits are present at transcription sites of Drosophila salivary gland chromosomes. Immunostaining was carried out with antibodies specific for 27 ribosomal proteins, two translation factors and one that specifically recognizes rRNA. In situ hybridization was with several probes specific for both rRNA subunits. The kinetics of recruitment following transcription initiation suggest that the association is with newly transcribed pol II transcripts. These data indicate that ribosome components associate with nascent RNP complexes within the nucleus.
人们普遍认为，真核生物核糖体首先在细胞质中与mRNA结合。然而，我们通过染色体免疫染色和原位杂交表明，核糖体亚基存在于果蝇唾液腺染色体的转录位点。使用针对27种核糖体蛋白、两种翻译因子和一种特异性识别rRNA的抗体进行免疫染色。原位杂交使用了几种针对两种rRNA亚基的特异性探针。转录起始后募集的动力学表明这种结合是与新转录的聚合酶II转录本相关。这些数据表明核糖体成分在细胞核内与新生的核糖核蛋白复合体结合。
