title: Insights into the mechanism of ribosomal incorporation of mammalian L13a protein during ribosome biogenesis.
abstract: In contrast to prokaryotes, the precise mechanism of incorporation of ribosomal proteins into ribosomes in eukaryotes is not well understood. For the majority of eukaryotic ribosomal proteins, residues critical for rRNA binding, a key step in the hierarchical assembly of ribosomes, have not been well defined. In this study, we used the mammalian ribosomal protein L13a as a model to investigate the mechanism(s) underlying eukaryotic ribosomal protein incorporation into ribosomes. This work identified the arginine residue at position 68 of L13a as being essential for L13a binding to rRNA and incorporation into ribosomes. We also demonstrated that incorporation of L13a takes place during maturation of the 90S preribosome in the nucleolus, but that translocation of L13a into the nucleolus is not sufficient for its incorporation into ribosomes. Incorporation of L13a into the 90S preribosome was required for rRNA methylation within the 90S complex. However, mutations abolishing ribosomal incorporation of L13a did not affect its ability to be phosphorylated or its extraribosomal function in GAIT element-mediated translational silencing. These results provide new insights into the mechanism of ribosomal incorporation of L13a and will be useful in guiding future studies aimed at fully deciphering mammalian ribosome biogenesis.
authors.affiliation: Center for Gene Regulation in Health & Disease, Department of Biology, Geology and Environmental Sciences, Cleveland State University, Cleveland, Ohio, USA.
authors.forename: Priyanka
authors.initials: P
authors.lastname: Das
authors.forename: Abhijit
authors.initials: A
authors.lastname: Basu
authors.forename: Aditi
authors.initials: A
authors.lastname: Biswas
authors.forename: Darshana
authors.initials: D
authors.lastname: Poddar
authors.forename: Joel
authors.initials: J
authors.lastname: Andrews
authors.forename: Sailen
authors.initials: S
authors.lastname: Barik
authors.forename: Anton A
authors.initials: AA
authors.lastname: Komar
authors.forename: Barsanjit
authors.initials: B
authors.lastname: Mazumder
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D057809:HEK293 Cells; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D008745:Methylation; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D017354:Point Mutation; D011485:Protein Binding; D012335:RNA, Ribosomal / Q000378:metabolism*; D012269:Ribosomal Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism*
chemical_list: D009363:Neoplasm Proteins; D012335:RNA, Ribosomal; C085488:RPL13 protein, human; D012269:Ribosomal Proteins; D007371:Interferon-gamma