Hurto Rebecca L, Tong Amy Hin Yan, Boone Charles, Hopper Anita K
Department of Molecular Genetics, Ohio State University, Columbus, Ohio 43210, USA.
Genetics. 2007 Jun;176(2):841-52. doi: 10.1534/genetics.106.069732. Epub 2007 Apr 3.
Nuclear export of tRNA is an essential eukaryotic function, yet the one known yeast tRNA nuclear exporter, Los1, is nonessential. Moreover recent studies have shown that tRNAs can move retrograde from the cytosol to the nucleus by an undefined process. Therefore, additional gene products involved in tRNA nucleus-cytosol dynamics have yet to be identified. Synthetic genetic array (SGA) analysis was employed to identify proteins involved in Los1-independent tRNA transport and in regulating tRNA nucleus-cytosol distribution. These studies uncovered synthetic interactions between los1Delta and pho88Delta involved in inorganic phopsphate uptake. Further analysis revealed that inorganic phosphate deprivation causes transient, temperature-dependent nuclear accumulation of mature cytoplasmic tRNA within nuclei via a Mtr10- and retrograde-dependent pathway, providing a novel connection between tRNA subcellular dynamics and phosphate availability.
转运RNA（tRNA）的核输出是真核生物的一项基本功能，然而，已知的酵母tRNA核输出蛋白Los1并非必不可少。此外，最近的研究表明，tRNA可以通过一个未明确的过程从细胞质逆行至细胞核。因此，尚未鉴定出参与tRNA核-质动态变化的其他基因产物。利用合成遗传阵列（SGA）分析来鉴定参与不依赖Los1的tRNA转运以及调节tRNA核-质分布的蛋白质。这些研究揭示了参与无机磷酸盐摄取的los1Δ和pho88Δ之间的合成相互作用。进一步分析表明，无机磷酸盐缺乏会通过依赖Mtr10和逆行的途径导致成熟细胞质tRNA在细胞核内短暂、温度依赖性的核积累，这为tRNA亚细胞动态变化与磷酸盐可用性之间提供了一种新的联系。
