title: Las1L is a nucleolar protein required for cell proliferation and ribosome biogenesis.
abstract: Ribosome biogenesis is a highly regulated process ensuring that cell growth (increase in biomass) is coordinated with cell proliferation. The formation of eukaryotic ribosomes is a multistep process initiated by the transcription and processing of rRNA in the nucleolus. Concomitant with this, several preribosomal particles, which transiently associate with numerous nonribosomal factors before mature 60S and 40S subunits are formed and exported in the cytoplasm, are generated. Here we identify Las1L as a previously uncharacterized nucleolar protein required for ribosome biogenesis. Depletion of Las1L causes inhibition of cell proliferation characterized by a G1 arrest dependent on the tumor suppressor p53. Moreover, we demonstrate that Las1L is crucial for ribosome biogenesis and that depletion of Las1L leads to inhibition of rRNA processing and failure to synthesize the mature 28S rRNA. Taken together, our data demonstrate that Las1L is essential for cell proliferation and biogenesis of the 60S ribosomal subunit.
authors.affiliation: Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, Texas 77030, USA.
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Castle
authors.forename: Erica K
authors.initials: EK
authors.lastname: Cassimere
authors.forename: Jinho
authors.initials: J
authors.lastname: Lee
authors.forename: Catherine
authors.initials: C
authors.lastname: Denicourt
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002453:Cell Cycle / Q000502:physiology; D002460:Cell Line; D049109:Cell Proliferation; D006801:Humans; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference; D012335:RNA, Ribosomal / Q000235:genetics / Q000378:metabolism; D054683:Ribosome Subunits, Large, Eukaryotic / Q000235:genetics / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism*; D016415:Sequence Alignment; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism
chemical_list: C552426:Las1L protein, human; D009687:Nuclear Proteins; D012335:RNA, Ribosomal; D016159:Tumor Suppressor Protein p53