Analysis of the in vivo assembly pathway of eukaryotic 40S ribosomal proteins.
In eukaryotes, in vivo formation of the two ribosomal subunits from four ribosomal RNAs (rRNAs) and approximately 80 ribosomal proteins (r-proteins) involves more than 150 nonribosomal proteins and around 100 small noncoding RNAs. It is temporally and spatially organized within different cellular compartments: the nucleolus, the nucleoplasm, and the cytoplasm. Here, we present a way to analyze how eukaryotic r-proteins of the small ribosomal subunit (SSU) assemble in vivo with rRNA. Our results show that key aspects of the assembly of eukaryotic r-proteins into distinct structural parts of the SSU are similar to the in vitro assembly pathway of their prokaryotic counterparts. We observe that the establishment of a stable assembly intermediate of the eukaryotic SSU body, but not of the SSU head, is closely linked to early rRNA processing events. The formation of assembly intermediates of the head controls efficient nuclear export of the SSU and cytoplasmic pre-rRNA maturation steps.
Ferreira-Cerca
Sébastien
S
Institut für Biochemie, Genetik und Mikrobiologie, University of Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany.
Pöll
Gisela
G
Kühn
Holger
H
Neueder
Andreas
A
Jakob
Steffen
S
Tschochner
Herbert
H
Milkereit
Philipp
P
D008954:Models, Biological; D012322:RNA Precursors / Q000737:chemistry / Q000378:metabolism; D012269:Ribosomal Proteins / Q000737:chemistry / Q000378:metabolism*; D054682:Ribosome Subunits, Small, Eukaryotic / Q000737:chemistry / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000378:metabolism*
D012322:RNA Precursors; D012269:Ribosomal Proteins; D029701:Saccharomyces cerevisiae Proteins; C032643:ribosomal protein S21; C030831:ribosomal protein S5