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Poly(A)-specific ribonuclease regulates the processing of small-subunit rRNAs in human cells

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posted on 2022-04-27, 00:55 authored by H Ishikawa, H Yoshikawa, K Izumikawa, Y Miura, M Taoka, Y Nobe, Y Yamauchi, H Nakayama, Richard SimpsonRichard Simpson, T Isobe, N Takahashi
Ribosome biogenesis occurs successively in the nucleolus, nucleoplasm, and cytoplasm. Maturation of the ribosomal small subunit is completed in the cytoplasm by incorporation of a particular class of ribosomal proteins and final cleavage of 18S-E prerRNA (18S-E). Here, we show that poly(A)-specific ribonuclease (PARN) participates in steps leading to 18S-E maturation in human cells. We found PARN as a novel component of the pre-40S particle pulled down with the pre-ribosome factor LTV1 or Bystin. Reverse pull-down analysis revealed that PARN is a constitutive component of the Bystin-associated pre-40S particle. Knockdown of PARN or exogenous expression of an enzyme-dead PARN mutant (D28A) accumulated 18S-E in both the cytoplasm and nucleus. Moreover, expression of D28A accumulated 18S-E in Bystin-associated pre-40S particles, suggesting that the enzymatic activity of PARN is necessary for the release of 18S-E from Bystin-associated pre-40S particles. Finally, RNase H-based fragmentation analysis and 3′-sequence analysis of 18S-E species present in cells expressing wild-type PARN or D28A suggested that PARN degrades the extended regions encompassing nucleotides 5-44 at the 3′ end of mature 18S rRNA. Our results reveal a novel role for PARN in ribosome biogenesis in human cells.


Core Research for Evolutional Science and Technology (CREST) from the Japan Science and Technology Agency (JST) [13415564]; Grant-in-Aid for Scientific Research, Ministry of Education, Culture, Sports, Science & Technology of Japan (MEXT) [24241075]; Global Innovation Research Organization of Tokyo University of Agriculture & Technology. Funding for open access charge: CREST/JST.


Publication Date



Nucleic Acids Research






11p. (p. 3437-3447)


Oxford University Press (OUP)



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© The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http: // / licenses / by-nc / 4.0 / ), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact