title: REEP3/4 ensure endoplasmic reticulum clearance from metaphase chromatin and proper nuclear envelope architecture.
abstract: Dynamic interactions between membrane-bound organelles and the microtubule cytoskeleton are crucial to establish, maintain, and remodel the internal organization of cells throughout the cell cycle. However, the molecular nature of these interactions remains poorly understood. We performed a biochemical screen for microtubule-membrane linkers and identified REEP4, a previously uncharacterized endoplasmic reticulum (ER) protein. Depletion of REEP4 and the closely related REEP3 from HeLa cells causes defects in cell division and a proliferation of intranuclear membranes derived from the nuclear envelope. This phenotype originates in mitosis, when ER membranes accumulate on metaphase chromosomes. Microtubule binding and mitotic ER clearance from chromosomes both depend on a short, positively charged amino acid sequence connecting the two hydrophobic domains of REEP4. Our results show that REEP3/4 function redundantly to clear the ER from metaphase chromatin, thereby ensuring correct progression through mitosis and proper nuclear envelope architecture.
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA. schlaitz@berkeley.edu
authors.forename: Anne-Lore
authors.initials: AL
authors.lastname: Schlaitz
authors.forename: James
authors.initials: J
authors.lastname: Thompson
authors.forename: Catherine C L
authors.initials: CC
authors.lastname: Wong
authors.forename: John R
authors.initials: JR
authors.lastname: Yates
authors.forename: Rebecca
authors.initials: R
authors.lastname: Heald
mesh_terms: D000595:Amino Acid Sequence; D002467:Cell Nucleus / Q000502:physiology; D002843:Chromatin / Q000378:metabolism*; D020090:Chromosome Segregation / Q000502:physiology; D004721:Endoplasmic Reticulum / Q000502:physiology*; D049452:Green Fluorescent Proteins; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D007399:Interphase / Q000502:physiology; D026901:Membrane Transport Proteins / Q000235:genetics* / Q000378:metabolism*; D008677:Metaphase / Q000502:physiology*; D008870:Microtubules / Q000378:metabolism; D008938:Mitosis / Q000502:physiology; D008969:Molecular Sequence Data; D009685:Nuclear Envelope / Q000502:physiology*
chemical_list: D002843:Chromatin; D026901:Membrane Transport Proteins; C520578:REEP3 protein, human; C584036:REEP4 protein, human; D049452:Green Fluorescent Proteins
references.citation: Cell. 1993 Jul 2;73(7):1267-79
references.pmid: 8324822
references.citation: Mol Biol Cell. 2012 Jul;23(13):2424-32
references.pmid: 22573885
references.citation: Dev Cell. 2012 Jul 17;23(1):153-65
references.pmid: 22814606
references.citation: Nature. 2010 Apr 1;464(7289):721-7
references.pmid: 20360735
references.citation: Cold Spring Harb Perspect Biol. 2010 Mar;2(3):a000539
references.pmid: 20300205
references.citation: Nat Protoc. 2006;1(5):2305-14
references.pmid: 17406472
references.citation: Mol Biol Cell. 2009 Aug;20(15):3471-80
references.pmid: 19494040
references.citation: J Cell Biol. 2007 Dec 3;179(5):895-909
references.pmid: 18056408
references.citation: J Cell Biol. 2007 Aug 13;178(4):595-610
references.pmid: 17698605
references.citation: Curr Biol. 2008 Feb 12;18(3):177-82
references.pmid: 18249114
references.citation: Cell. 2006 Feb 10;124(3):573-86
references.pmid: 16469703
references.citation: J Cell Biol. 2008 Sep 8;182(5):911-24
references.pmid: 18779370
references.citation: Dev Cell. 2011 Dec 13;21(6):1171-8
references.pmid: 22172677
references.citation: Cell. 2002 Jan 11;108(1):83-96
references.pmid: 11792323
references.citation: J Clin Invest. 2010 Apr;120(4):1097-110
references.pmid: 20200447
references.citation: Curr Biol. 2012 Aug 21;22(16):1487-93
references.pmid: 22748319
references.citation: Mol Biosyst. 2007 Sep;3(9):583-9
references.pmid: 17700857
references.citation: Cell. 2002 Jan 11;108(1):97-107
references.pmid: 11792324
references.citation: Trends Cell Biol. 2011 Jun;21(6):362-73
references.pmid: 21514163
references.citation: Cell. 1992 Sep 18;70(6):887-900
references.pmid: 1356075