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

Publication date: Available online 25 January 2020Source: Biochimica et Biophysica Acta (BBA) - Gene Regulatory MechanismsAuthor(s): Konstantin Bulygin, Alexey Malygin, Alexander Gopanenko, Dmitri Graifer, Galina KarpovaAbstractThe 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 ...

Source: Biochimica et Biophysica Acta (BBA) Gene Regulatory Mechanisms - January 26, 2020 Category: Genetics & Stem Cells Source Type: research