title: Diffusion-based transport of nascent ribosomes in the nucleus.
abstract: Although the complex process of ribosome assembly in the nucleolus is beginning to be understood, little is known about how the ribosomal subunits move from the nucleolus to the nuclear membrane for transport to the cytoplasm. We show here that large ribosomal subunits move out from the nucleolus and into the nucleoplasm in all directions, with no evidence of concentrated movement along directed paths. Mobility was slowed compared with that expected in aqueous solution in a manner consistent with anomalous diffusion. Once nucleoplasmic, the subunits moved in the same random manner and also sometimes visited another nucleolus before leaving the nucleus.
authors.affiliation: Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA. joan.politz@umassmed.edu
authors.forename: Joan C Ritland
authors.initials: JC
authors.lastname: Politz
authors.forename: Richard A
authors.initials: RA
authors.lastname: Tuft
authors.forename: Thoru
authors.initials: T
authors.lastname: Pederson
mesh_terms: D000818:Animals; D001692:Biological Transport / Q000502:physiology; D002466:Cell Nucleolus / Q000378:metabolism / Q000502:physiology*; D002478:Cells, Cultured; D003593:Cytoplasm / Q000378:metabolism / Q000502:physiology*; D007091:Image Processing, Computer-Assisted; D017403:In Situ Hybridization; D018715:Microscopy, Video; D032446:Myoblasts / Q000378:metabolism / Q000502:physiology*; D012335:RNA, Ribosomal / Q000378:metabolism / Q000502:physiology*; D051381:Rats; D012270:Ribosomes / Q000378:metabolism / Q000502:physiology*
chemical_list: D012335:RNA, Ribosomal