TY - JOUR

T1 - The functional role of the C-terminal tail of the human ribosomal protein uS19

AU - Bulygin, Konstantin

AU - Malygin, Alexey

AU - Gopanenko, Alexander

AU - Graifer, Dmitri

AU - Karpova, Galina

N1 - Publisher Copyright: © 2020 Elsevier B.V.

PY - 2020/3

Y1 - 2020/3

N2 - The eukaryotic ribosomal protein uS19 has a C-terminal tail that is absent in its bacterial homologue. This tail has been shown to be involved in the formation of the decoding site of human ribosomes. We studied here the previously unexplored functional significance of the 15 C-terminal amino acid residues of human uS19 for the assembly of ribosomes and translation using HEK293-based cell cultures capable of producing FLAG-labeled uS19 (uS19FLAG) or its mutant form deprived of the mentioned amino acid ones. The examination of polysome profiles of cytoplasmic extracts from the respective cells revealed that the deletion of the above uS19 amino acid residues barely affected the assembly and maturation of 40S subunits and the initiation of translation, but completely prevented the formation of polysomes. This implied the crucial importance of the uS19 tail in the elongation process. Analysis of tRNAs associated with 40S subunits and 80S ribosomes containing wild type uS19FLAG or its truncated form showed that the deletion of the C-terminal pentadecapeptide fragment of uS19 did not interfere with the binding of aminoacyl-tRNA (aa-tRNA) at the ribosomal A site. The results led to the conclusion that the transpeptidation, which occurs on the large ribosomal subunit after decoding the A site codon by the incoming aa-tRNA, is the most likely elongation stage, where this uS19 fragment can play a critical role. Our findings suggest that the uS19 tail is a keystone player in the accommodation of aa-tRNA at the A site, which is a pre-requisite for the peptide transfer.

AB - The eukaryotic ribosomal protein uS19 has a C-terminal tail that is absent in its bacterial homologue. This tail has been shown to be involved in the formation of the decoding site of human ribosomes. We studied here the previously unexplored functional significance of the 15 C-terminal amino acid residues of human uS19 for the assembly of ribosomes and translation using HEK293-based cell cultures capable of producing FLAG-labeled uS19 (uS19FLAG) or its mutant form deprived of the mentioned amino acid ones. The examination of polysome profiles of cytoplasmic extracts from the respective cells revealed that the deletion of the above uS19 amino acid residues barely affected the assembly and maturation of 40S subunits and the initiation of translation, but completely prevented the formation of polysomes. This implied the crucial importance of the uS19 tail in the elongation process. Analysis of tRNAs associated with 40S subunits and 80S ribosomes containing wild type uS19FLAG or its truncated form showed that the deletion of the C-terminal pentadecapeptide fragment of uS19 did not interfere with the binding of aminoacyl-tRNA (aa-tRNA) at the ribosomal A site. The results led to the conclusion that the transpeptidation, which occurs on the large ribosomal subunit after decoding the A site codon by the incoming aa-tRNA, is the most likely elongation stage, where this uS19 fragment can play a critical role. Our findings suggest that the uS19 tail is a keystone player in the accommodation of aa-tRNA at the A site, which is a pre-requisite for the peptide transfer.

KW - Aminoacyl-tRNA accommodation

KW - Decoding site

KW - Deletion of uS19 C-terminal amino acid residues

KW - Human ribosomal protein uS19

KW - Small ribosomal subunit

KW - Translation elongation

KW - CONTACTS

KW - SITE

KW - STATES

KW - CRYSTAL-STRUCTURE

KW - STOP CODONS

KW - RELEASE FACTOR ERF1

KW - ELEMENTS

KW - MESSENGER-RNA

KW - ELONGATION

KW - SUBUNIT

UR - http://www.scopus.com/inward/record.url?scp=85078722479&partnerID=8YFLogxK

U2 - 10.1016/j.bbagrm.2020.194490

DO - 10.1016/j.bbagrm.2020.194490

M3 - Article

C2 - 31991215

AN - SCOPUS:85078722479

VL - 1863

JO - Biochimica et Biophysica Acta - Gene Regulatory Mechanisms

JF - Biochimica et Biophysica Acta - Gene Regulatory Mechanisms

SN - 1874-9399

IS - 3

M1 - 194490

ER -