Nuclear export and cytoplasmic maturation of ribosomal subunits.
Based on the characterization of ribosome precursor particles and associated trans-acting factors, a biogenesis pathway for the 40S and 60S subunits has emerged. After nuclear synthesis and assembly steps, pre-ribosomal subunits are exported through the nuclear pore complex in a Crm1- and RanGTP-dependent manner. Subsequent cytoplasmic biogenesis steps of pre-60S particles include the facilitated release of several non-ribosomal proteins, yielding fully functional 60S subunits. Cytoplasmic maturation of 40S subunit precursors includes rRNA dimethylation and pre-rRNA cleavage, allowing 40S subunits to achieve translation competence. We review current knowledge of nuclear export and cytoplasmic maturation of ribosomal subunits.
Zemp
Ivo
I
Institute of Biochemistry, HPM F11.1, Schafmattstr. 18, ETH Zurich, 8093 Zurich, Switzerland.
Kutay
Ulrike
U
D021581:Active Transport, Cell Nucleus; D000818:Animals; D003593:Cytoplasm / Q000378:metabolism; D008954:Models, Biological; D021122:Protein Subunits; D012322:RNA Precursors / Q000737:chemistry / Q000378:metabolism; D012331:RNA, Fungal / Q000737:chemistry / Q000378:metabolism; D012335:RNA, Ribosomal / Q000737:chemistry / Q000378:metabolism; D012269:Ribosomal Proteins / Q000737:chemistry / Q000378:metabolism; D012270:Ribosomes / Q000737:chemistry* / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000378:metabolism
D021122:Protein Subunits; D012322:RNA Precursors; D012331:RNA, Fungal; D012335:RNA, Ribosomal; D012269:Ribosomal Proteins; D029701:Saccharomyces cerevisiae Proteins