title: The molecular architecture of lamins in somatic cells.
abstract: The nuclear lamina is a fundamental constituent of metazoan nuclei. It is composed mainly of lamins, which are intermediate filament proteins that assemble into a filamentous meshwork, bridging the nuclear envelope and chromatin. Besides providing structural stability to the nucleus, the lamina is involved in many nuclear activities, including chromatin organization, transcription and replication. However, the structural organization of the nuclear lamina is poorly understood. Here we use cryo-electron tomography to obtain a detailed view of the organization of the lamin meshwork within the lamina. Data analysis of individual lamin filaments resolves a globular-decorated fibre appearance and shows that A- and B-type lamins assemble into tetrameric filaments of 3.5 nm thickness. Thus, lamins exhibit a structure that is remarkably different from the other canonical cytoskeletal elements. Our findings define the architecture of the nuclear lamin meshworks at molecular resolution, providing insights into their role in scaffolding the nuclear lamina.
authors.affiliation: Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.
authors.forename: Yagmur
authors.initials: Y
authors.lastname: Turgay
authors.affiliation: Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.
authors.forename: Matthias
authors.initials: M
authors.lastname: Eibauer
authors.affiliation: Department of Cell and Molecular Biology, Northwestern University Feinberg School of Medicine, 303 E Chicago Avenue, Chicago, Illinois 60611, USA.
authors.forename: Anne E
authors.initials: AE
authors.lastname: Goldman
authors.affiliation: Department of Cell and Molecular Biology, Northwestern University Feinberg School of Medicine, 303 E Chicago Avenue, Chicago, Illinois 60611, USA.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Shimi
authors.affiliation: Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University, 84105 Beer-Sheva, Israel.
authors.forename: Maayan
authors.initials: M
authors.lastname: Khayat
authors.affiliation: Department of Chemical Engineering, Shamoon College of Engineering, Jabotinsky 84, 77245 Ashdod, Israel.
authors.forename: Kfir
authors.initials: K
authors.lastname: Ben-Harush
authors.affiliation: Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.
authors.forename: Anna
authors.initials: A
authors.lastname: Dubrovsky-Gaupp
authors.affiliation: Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.
authors.forename: K Tanuj
authors.initials: KT
authors.lastname: Sapra
authors.affiliation: Department of Cell and Molecular Biology, Northwestern University Feinberg School of Medicine, 303 E Chicago Avenue, Chicago, Illinois 60611, USA.
authors.forename: Robert D
authors.initials: RD
authors.lastname: Goldman
authors.affiliation: Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.|Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University, 84105 Beer-Sheva, Israel.
authors.forename: Ohad
authors.initials: O
authors.lastname: Medalia
mesh_terms: D000818:Animals; D002843:Chromatin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D020285:Cryoelectron Microscopy; D003599:Cytoskeleton / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure; D006801:Humans; D007381:Intermediate Filament Proteins / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure; D034882:Lamins / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure*; D051379:Mice; D034881:Nuclear Lamina / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure*; D014054:Tomography
chemical_list: D002843:Chromatin; D007381:Intermediate Filament Proteins; D034882:Lamins