title: The ribosomal protein Rpl22 controls ribosome composition by directly repressing expression of its own paralog, Rpl22l1.
abstract: Most yeast ribosomal protein genes are duplicated and their characterization has led to hypotheses regarding the existence of specialized ribosomes with different subunit composition or specifically-tailored functions. In yeast, ribosomal protein genes are generally duplicated and evidence has emerged that paralogs might have specific roles. Unlike yeast, most mammalian ribosomal proteins are thought to be encoded by a single gene copy, raising the possibility that heterogenous populations of ribosomes are unique to yeast. Here, we examine the roles of the mammalian Rpl22, finding that Rpl22(-/-) mice have only subtle phenotypes with no significant translation defects. We find that in the Rpl22(-/-) mouse there is a compensatory increase in Rpl22-like1 (Rpl22l1) expression and incorporation into ribosomes. Consistent with the hypothesis that either ribosomal protein can support translation, knockdown of Rpl22l1 impairs growth of cells lacking Rpl22. Mechanistically, Rpl22 regulates Rpl22l1 directly by binding to an internal hairpin structure and repressing its expression. We propose that ribosome specificity may exist in mammals, providing evidence that one ribosomal protein can influence composition of the ribosome by regulating its own paralog.
authors.affiliation: Department of Biochemistry, University of Washington, Seattle, Washington, United States of America.
authors.forename: Monique N
authors.initials: MN
authors.lastname: O'Leary
authors.forename: Katherine H
authors.initials: KH
authors.lastname: Schreiber
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhang
authors.forename: Anne-Cécile E
authors.initials: AC
authors.lastname: Duc
authors.forename: Shuyun
authors.initials: S
authors.lastname: Rao
authors.forename: J Scott
authors.initials: JS
authors.lastname: Hale
authors.forename: Emmeline C
authors.initials: EC
authors.lastname: Academia
authors.forename: Shreya R
authors.initials: SR
authors.lastname: Shah
authors.forename: John F
authors.initials: JF
authors.lastname: Morton
authors.forename: Carly A
authors.initials: CA
authors.lastname: Holstein
authors.forename: Dan B
authors.initials: DB
authors.lastname: Martin
authors.forename: Matt
authors.initials: M
authors.lastname: Kaeberlein
authors.forename: Warren C
authors.initials: WC
authors.lastname: Ladiges
authors.forename: Pamela J
authors.initials: PJ
authors.lastname: Fink
authors.forename: Vivian L
authors.initials: VL
authors.lastname: Mackay
authors.forename: David L
authors.initials: DL
authors.lastname: Wiest
authors.forename: Brian K
authors.initials: BK
authors.lastname: Kennedy
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D005786:Gene Expression Regulation; D051379:Mice; D008969:Molecular Sequence Data; D014176:Protein Biosynthesis; D012313:RNA / Q000235:genetics* / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D012269:Ribosomal Proteins / Q000235:genetics* / Q000378:metabolism; D012270:Ribosomes / Q000235:genetics* / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
chemical_list: D016601:RNA-Binding Proteins; C522051:RPL22 protein, mouse; C000608557:RPL22L1 protein, mouse; D012269:Ribosomal Proteins; D012313:RNA