Sarkar S, Azad A K, Hopper A K
Department of Biochemistry, Pennsylvania State University, College of Medicine, Hershey, PA, 17033, USA.
Proc Natl Acad Sci U S A. 1999 Dec 7;96(25):14366-71. doi: 10.1073/pnas.96.25.14366.
Nuclear tRNA aminoacylation was proposed to provide a proofreading step in Xenopus oocytes, ensuring nuclear export of functional tRNAs [Lund, E. & Dahlberg, J. E. (1998) Science 282, 2082-2085]. Herein, it is documented that tRNA aminoacylation also occurs in yeast nuclei and is important for tRNA export. We propose that tRNA aminoacylation functions in one of at least two parallel paths of tRNA export in yeast. Alteration of one aminoacyl-tRNA synthetase affects export of only cognate tRNA, whereas alterations of two other aminoacyl-tRNA synthetases affect export of both cognate and noncognate tRNAs. Saturation of tRNA export pathway is a possible explanation of this phenomenon.
核tRNA氨基酰化被认为是非洲爪蟾卵母细胞中的一个校对步骤,可确保功能性tRNA的核输出[Lund, E. & Dahlberg, J. E. (1998) Science 282, 2082 - 2085]。在此文中,有文献记载tRNA氨基酰化也发生在酵母细胞核中,并且对tRNA输出很重要。我们提出tRNA氨基酰化在酵母中tRNA输出的至少两条平行途径之一中发挥作用。一种氨酰tRNA合成酶的改变仅影响同源tRNA的输出,而另外两种氨酰tRNA合成酶的改变则影响同源和非同源tRNA的输出。tRNA输出途径的饱和可能是对此现象的一种解释。