BIOGRID CURATED DATA FOR PUBLICATION: Role of Mex67-Mtr2 in the nuclear export of 40S pre-ribosomes.

Protein-Protein, Genetic, and Chemical Interactions for Faza MB (2012):Role of Mex67-Mtr2 in the nuclear export of 40S pre-ribosomes. curated by BioGRID (https://thebiogrid.org); ABSTRACT: Nuclear export of mRNAs and pre-ribosomal subunits (pre40S and pre60S) is fundamental to all eukaryotes. While genetic approaches in budding yeast have identified bona fide export factors for mRNAs and pre60S subunits, little is known regarding nuclear export of pre40S subunits. The yeast heterodimeric transport receptor Mex67-Mtr2 (TAP-p15 in humans) binds mRNAs and pre60S subunits in the nucleus and facilitates their passage through the nuclear pore complex (NPC) into the cytoplasm by interacting with Phe-Gly (FG)-rich nucleoporins that line its transport channel. By exploiting a combination of genetic, cell-biological, and biochemical approaches, we uncovered an unanticipated role of Mex67-Mtr2 in the nuclear export of 40S pre-ribosomes. We show that recruitment of Mex67-Mtr2 to pre40S subunits requires loops emanating from its NTF2-like domains and that the C-terminal FG-rich nucleoporin interacting UBA-like domain within Mex67 contributes to the transport of pre40S subunits to the cytoplasm. Remarkably, the same loops also recruit Mex67-Mtr2 to pre60S subunits and to the Nup84 complex, the respective interactions crucial for nuclear export of pre60S subunits and mRNAs. Thus Mex67-Mtr2 is a unique transport receptor that employs a common interaction surface to participate in the nuclear export of both pre-ribosomal subunits and mRNAs. Mex67-Mtr2 could engage a regulatory crosstalk among the three major export pathways for optimal cellular growth and proliferation.

蛋白质-蛋白质、遗传和化学相互作用数据集 Faza MB (2012)：Mex67-Mtr2 在 40S 预核糖体核输出中的作用。由 BioGRID（https://thebiogrid.org）编纂；摘要：mRNA 和前核糖体亚基（前40S 和前60S）的核输出对于所有真核生物而言至关重要。尽管在酵母中的遗传学研究已经鉴定出 mRNA 和前60S 亚基的有效输出因子，但对于前40S 亚基的核输出知之甚少。酵母异源二聚体转运受体 Mex67-Mtr2（人类中的 TAP-p15）在细胞核中与 mRNA 和前60S 亚基结合，并通过与构成其转运通道的富含 Phe-Gly（FG）的核孔蛋白相互作用，促进它们通过核孔复合物（NPC）进入细胞质。通过结合遗传学、细胞生物学和生化方法，我们揭示了 Mex67-Mtr2 在 40S 预核糖体核输出中未曾预料的角色。我们发现，Mex67-Mtr2 对前40S 亚基的募集需要其 NTF2-like 结构域发出的环状结构，而 Mex67 中富含 FG 的核孔蛋白相互作用 UBA-like 结构域的 C 端有助于将前40S 亚基转运至细胞质。值得注意的是，相同的环状结构也能将 Mex67-Mtr2 募集到前60S 亚基和 Nup84 复合物上，这些交互作用对于前60S 亚基和 mRNA 的核输出至关重要。因此，Mex67-Mtr2 是一种独特的转运受体，它利用共同的作用表面参与前核糖体亚基和 mRNA 的核输出。Mex67-Mtr2 可能会介导三种主要输出途径之间的调节性串扰，以优化细胞生长和增殖。