POLYCISTRONIC TRANSCRIPTS IN TRYPANOSOMES AND THEIR ACCUMULATION DURING HEAT-SHOCK - EVIDENCE FOR A PRECURSOR ROLE IN MESSENGER-RNA SYNTHESIS
POLYCISTRONIC TRANSCRIPTS IN TRYPANOSOMES AND THEIR ACCUMULATION DURING HEAT-SHOCK - EVIDENCE FOR A PRECURSOR ROLE IN MESSENGER-RNA SYNTHESIS
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DOI：
10.1128/mcb.8.9.3837
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发表时间：
1988-09-01
影响因子：
5.3
通讯作者：
BOOTHROYD, JC
中科院分区：
文献类型：
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作者：
MUHICH, ML;BOOTHROYD, JC
锥虫体内mRNA前体的成熟涉及一个明显的反式剪接事件，在该事件中，一个39个核苷酸的微小外显子序列被连接到蛋白质编码外显子的5‘端，这是所有锥虫mRNAs共有的。我们证明，负责布鲁氏锥虫微管蛋白前体成熟的加工机制可以被热休克破坏。这导致多顺反子RNA物种的积累和分支剪接中间体的丰度下降。在常温下，也可以检测到微管蛋白多顺反子转录本，并在脉冲追逐实验中显示出大量合成和非常迅速的翻转。这些结果与热休克实验结果相结合，表明这些多顺反子转录本是锥虫(单顺反子)微管蛋白mRNAs的前体。
Maturation of mRNA precursors in trypanosomes involves an apparent trans splicing event in which a 39-nuceotide miniexon sequence, common to all trypanosome mRNAs, is joined to the 5'' end of a protein-coding exon. We demonstrate that the processing machinery responsible for the maturation of tubulin mRNA precursors in Trypanosoma brucei can be disrupted by heat shock. This result in an accumulation of polycistronic RNa species and a decrease in the abundance of branched splicing intermediates. At normal temperatures, tubulin polycistronic transcripts were also detected and were shown in pulse-chase experiments to be abundantly synthesized and very rapidly turned over. These results, combined with results of the heat shock experiments, suggest that these polycistronic transcripts are the precursors of the (monocistronic) tubulin mRNAs of trypanosomes.