title: Cell nuclei spin in the absence of lamin b1.
abstract: Mutations of the nuclear lamins cause a wide range of human diseases, including Emery-Dreifuss muscular dystrophy and Hutchinson-Gilford progeria syndrome. Defects in A-type lamins reduce nuclear structural integrity and affect transcriptional regulation, but few data exist on the biological role of B-type lamins. To assess the functional importance of lamin B1, we examined nuclear dynamics in fibroblasts from Lmnb1(Delta/Delta) and wild-type littermate embryos by time-lapse videomicroscopy. Here, we report that Lmnb1(Delta/Delta) cells displayed striking nuclear rotation, with approximately 90% of Lmnb1(Delta/Delta) nuclei rotating at least 90 degrees during an 8-h period. The rotation involved the nuclear interior as well as the nuclear envelope. The rotation of nuclei required an intact cytoskeletal network and was eliminated by expressing lamin B1 in cells. Nuclear rotation could also be abolished by expressing larger nesprin isoforms with long spectrin repeats. These findings demonstrate that lamin B1 serves a fundamental role within the nuclear envelope: anchoring the nucleus to the cytoskeleton.
authors.affiliation: Cardiovascular Division, Brigham and Women's Hospital, Cambridge, Massachusetts 02139, USA.
authors.forename: Julie Y
authors.initials: JY
authors.lastname: Ji
authors.forename: Richard T
authors.initials: RT
authors.lastname: Lee
authors.forename: Laurent
authors.initials: L
authors.lastname: Vergnes
authors.forename: Loren G
authors.initials: LG
authors.lastname: Fong
authors.forename: Colin L
authors.initials: CL
authors.lastname: Stewart
authors.forename: Karen
authors.initials: K
authors.lastname: Reue
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Young
authors.forename: Qiuping
authors.initials: Q
authors.lastname: Zhang
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Shanahan
authors.forename: Jan
authors.initials: J
authors.lastname: Lammerding
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D003599:Cytoskeleton / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D004622:Embryo, Mammalian / Q000378:metabolism* / Q000473:pathology; D005347:Fibroblasts / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D042581:Intranuclear Space / Q000378:metabolism / Q000473:pathology; D034921:Lamin Type B / Q000172:deficiency / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D018715:Microscopy, Video; D009685:Nuclear Envelope / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D011371:Progeria / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D013997:Time Factors
chemical_list: D034921:Lamin Type B