Logo Logo
Help
Contact
Switch Language to German
Sarkar, Anshuk; Pech, Markus; Thoms, Matthias; Beckmann, Roland; Hurt, Ed (2016): Ribosome-stalk biogenesis is coupled with recruitment of nuclear-export factor to the nascent 60S subunit. In: Nature Structural & Molecular Biology, Vol. 23, No. 12: pp. 1074-1082
Full text not available from 'Open Access LMU'.

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.