title: Ribosome-stalk biogenesis is coupled with recruitment of nuclear-export factor to the nascent 60S subunit.
abstract: Nuclear export of preribosomal subunits is a key step during eukaryotic ribosome formation. To efficiently pass through the FG-repeat meshwork of the nuclear pore complex, the large pre-60S subunit requires several export factors. Here we describe the mechanism of recruitment of the Saccharomyces cerevisiae RNA-export receptor Mex67-Mtr2 to the pre-60S subunit at the proper time. Mex67-Mtr2 binds at the premature ribosomal-stalk region, which later during translation serves as a binding platform for translational GTPases on the mature ribosome. The assembly factor Mrt4, a structural homolog of cytoplasmic-stalk protein P0, masks this site, thus preventing untimely recruitment of Mex67-Mtr2 to nuclear pre-60S particles. Subsequently, Yvh1 triggers Mrt4 release in the nucleus, thereby creating a narrow time window for Mex67-Mtr2 association at this site and facilitating nuclear export of the large subunit. Thus, a spatiotemporal mark on the ribosomal stalk controls the recruitment of an RNA-export receptor to the nascent 60S subunit.
authors: Biochemistry Centre, University of Heidelberg, Heidelberg, Germany.
authors: Anshuk
authors: A
authors: Sarkar
authors: Gene Center, University of Munich, Munich, Germany.
authors: Markus
authors: M
authors: Pech
authors: Biochemistry Centre, University of Heidelberg, Heidelberg, Germany.
authors: Matthias
authors: M
authors: Thoms
authors: Gene Center, University of Munich, Munich, Germany.
authors: Roland
authors: R
authors: Beckmann
authors: Biochemistry Centre, University of Heidelberg, Heidelberg, Germany.
authors: Ed
authors: E
authors: Hurt
mesh_terms: D021581:Active Transport, Cell Nucleus; D001483:Base Sequence; D001665:Binding Sites; D026901:Membrane Transport Proteins / Q000737:chemistry / Q000378:metabolism*; D008958:Models, Molecular; D009687:Nuclear Proteins / Q000737:chemistry / Q000378:metabolism*; D029543:Nucleocytoplasmic Transport Proteins / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D034443:RNA Transport; D012331:RNA, Fungal / Q000737:chemistry / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D054658:Ribosome Subunits, Large / Q000737:chemistry / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000378:metabolism*
chemical_list: C106898:MEX67 protein, S cerevisiae; D026901:Membrane Transport Proteins; C480169:Mtr2 protein, S cerevisiae; D009687:Nuclear Proteins; D029543:Nucleocytoplasmic Transport Proteins; D012331:RNA, Fungal; D016601:RNA-Binding Proteins; D029701:Saccharomyces cerevisiae Proteins