Trypanosome MTR4 is involved in rRNA processing
Trypanosome MTR4 is involved in rRNA processing
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DOI：
10.1093/nar/gkm736
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发表时间：
2007-11-01
影响因子：
14.9
通讯作者：
Clayton, Christine E.
中科院分区：
文献类型：
--
作者：
Cristodero, Marina;Clayton, Christine E.
酵母推测的RNA解旋酶Mtr4p参与细胞核内外泌体介导的RNA质量控制，与外泌体相互作用，存在于酵母核多聚(a)聚合酶（Trf4p/Pap2p或Trf5p）和推测的RNA结合蛋白Air1p或Air2p的“TRAMP”复合体中。布鲁氏锥虫mtr4样蛋白TbMTR4的缺失导致生长停滞和5.8S rRNA加工缺陷，类似于外泌体缺失后的情况。TbNPAPL是一种核蛋白，被认为是Trf4p/Pap2p的同源物，是正常细胞生长所必需的。MTR4的缺失导致多腺苷化rRNA前体的积累，而TbNPAPL的缺失几乎没有影响。这些结果表明，聚腺苷化依赖的核rRNA质量控制在真核生物进化中是保守的。相比之下，由于没有检测到TbMTR4与外泌体、TbNPAPL或rna结合蛋白之间的稳定相互作用，因此没有证据表明锥虫存在TRAMP复合物。
The yeast putative RNA helicase Mtr4p is implicated in exosome-mediated RNA quality control in the nucleus, interacts with the exosome, and is found in the 'TRAMP' complex with a yeast nuclear poly(A) polymerase (Trf4p/Pap2p or Trf5p) and a putative RNA-binding protein, Air1p or Air2p. Depletion of the Trypanosoma brucei MTR4-like protein TbMTR4 caused growth arrest and defects in 5.8S rRNA processing similar to those seen after depletion of the exosome. TbNPAPL, a nuclear protein which is a putative homolog of Trf4p/Pap2p, was required for normal cell growth. Depletion of MTR4 resulted in the accumulation of polyadenylated rRNA precursors, while depletion of TbNPAPL had little effect. These results suggest that polyadenylation-dependent nuclear rRNA quality control is conserved in eukaryotic evolution. In contrast, there was no evidence for a trypanosome TRAMP complex since no stable interactions between TbMTR4 and the exosome, TbNPAPL or RNA-binding proteins were detected.