18SE pre-rRNA in pre-40S particles is nucleolytically processed during translocation from the nucleus to the cytosol

Stable Identifier
Reaction [omitted]
Homo sapiens
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Exonuclease activity of the exosome (Preti et al. 2013) and endonuclease activity of NOB1 (inferred from yeast, Pertschy et al. 2009) process the 3' end of precursor rRNA (pre-rRNA) 18SE to yield mature 18S rRNA. During the processing, pre-rRNA 18SE is bound in the pre-40S ribosome subunit, which contains ribosomal proteins and processing factors such as NOB1 and BYSL. The pre-40S subunit is exported from the nucleus to the cytosol where processing factors are released and recycled back to the nucleus. The kinases RIOK1, RIOK2, CSNK1D and CSNK1E are associated with the pre-40S rRNA subunit in both the nucleus and cytosol and their kinase activity is required for recycling of processing factors back to the nucleus (Zemp et al. 2009, Zemp et al. 2014). RIOK1 and RIOK2 are also required for 18SE processing (Widmann et al. 2012, Zemp et al. 2009). RIOK3 (RIO3) is a cytosolic kinase that associates with the pre-40S ribosomal particle after export from the nucleus and is required for release of processing factors (Baumas et al. 2012).
Literature References
PubMed ID Title Journal Year
22072790 The kinase activity of human Rio1 is required for final steps of cytoplasmic maturation of 40S subunits

Widmann, B, Pfannstiel, J, Badertscher, L, Wandrey, F, Wyler, E, Zemp, I, Kutay, U

Mol. Biol. Cell 2012
19801658 RNA helicase Prp43 and its co-factor Pfa1 promote 20 to 18 S rRNA processing catalyzed by the endonuclease Nob1

Tollervey, D, Gnädig, M, Schneider, C, Hurt, E, Pertschy, B, Schäfer, T

J. Biol. Chem. 2009
16037817 Nuclear export and cytoplasmic processing of precursors to the 40S ribosomal subunits in mammalian cells

Rouquette, J, Choesmel, V, Gleizes, PE

EMBO J. 2005
20805244 Analysis of two human pre-ribosomal factors, bystin and hTsr1, highlights differences in evolution of ribosome biogenesis between yeast and mammals

O'Donohue, MF, Carron, C, Faubladier, M, Choesmel, V, Gleizes, PE

Nucleic Acids Res. 2011
25525153 WBSCR22/Merm1 is required for late nuclear pre-ribosomal RNA processing and mediates N7-methylation of G1639 in human 18S rRNA

Haag, S, Kretschmer, J, Bohnsack, MT

RNA 2015
21097556 Tandem affinity purification combined with inducible shRNA expression as a tool to study the maturation of macromolecular assemblies

Widmann, B, Gstaiger, M, Pfannstiel, J, Zimmermann, M, Wyler, E, Zemp, I, Kutay, U

RNA 2011
23482395 Gradual processing of the ITS1 from the nucleolus to the cytoplasm during synthesis of the human 18S rRNA

Preti, M, O'Donohue, MF, Bortolin-Cavaillé, ML, Choesmel, V, Gleizes, PE, Montel-Lehry, N

Nucleic Acids Res. 2013
24424021 CK1δ and CK1ε are components of human 40S subunit precursors required for cytoplasmic 40S maturation

Ashiono, C, Montellese, C, Wandrey, F, Wyler, E, Zemp, I, Kutay, U, Rao, S

J. Cell. Sci. 2014
19564402 Distinct cytoplasmic maturation steps of 40S ribosomal subunit precursors require hRio2

Widmann, B, Wild, T, O'Donohue, MF, Wandrey, F, Zemp, I, Kutay, U, Gleizes, PE

J. Cell Biol. 2009
Catalyst Activity

endoribonuclease activity of NOB1 [cytosol]

This event is regulated
Orthologous Events
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