title: FHOD1 interaction with nesprin-2G mediates TAN line formation and nuclear movement.
abstract: Active positioning of the nucleus is integral to division, migration and differentiation of mammalian cells. Fibroblasts polarizing for migration orient their centrosomes by actin-dependent nuclear movement. This nuclear movement depends on nesprin-2 giant (N2G), a large, actin-binding outer nuclear membrane component of transmembrane actin-associated (TAN) lines that couple nuclei to moving actin cables. Here, we identify the diaphanous formin FHOD1 as an interaction partner of N2G. Silencing FHOD1 expression or expression of fragments containing binding sites for N2G or FHOD1 disrupted nuclear movement and centrosome orientation in polarizing fibroblasts. Unexpectedly, silencing of FHOD1 expression did not affect the formation or rearward flow of dorsal actin cables required for nuclear positioning. Rather, N2G-FHOD1 interaction provided a second connection to actin cables essential for TAN line formation and thus nuclear movement. These results reveal a unique function for a formin in coupling an organelle to actin filaments for translocation, and suggest that TAN lines require multi-point attachments to actin cables to resist the large forces necessary to move the nucleus.
authors.affiliation: 1] Department of Infectious Diseases, Integrative Virology, University Hospital Heidelberg, Heidelberg, INF 324, 69120 Heidelberg, Germany [2].
authors.forename: Stefan
authors.initials: S
authors.lastname: Kutscheidt
authors.affiliation: 1] Department of Pathology and Cell Biology, Columbia University, New York, New York 10032, USA [2].
authors.forename: Ruijun
authors.initials: R
authors.lastname: Zhu
authors.affiliation: 1] Department of Pathology and Cell Biology, Columbia University, New York, New York 10032, USA [2].
authors.forename: Susumu
authors.initials: S
authors.lastname: Antoku
authors.affiliation: 1] Department of Pathology and Cell Biology, Columbia University, New York, New York 10032, USA [2].
authors.forename: G W Gant
authors.initials: GW
authors.lastname: Luxton
authors.affiliation: Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 3E1, Canada.
authors.forename: Igor
authors.initials: I
authors.lastname: Stagljar
authors.affiliation: Department of Infectious Diseases, Integrative Virology, University Hospital Heidelberg, Heidelberg, INF 324, 69120 Heidelberg, Germany.
authors.forename: Oliver T
authors.initials: OT
authors.lastname: Fackler
authors.affiliation: Department of Pathology and Cell Biology, Columbia University, New York, New York 10032, USA.
authors.forename: Gregg G
authors.initials: GG
authors.lastname: Gundersen
mesh_terms: D000199:Actins / Q000378:metabolism*; D000818:Animals; D015153:Blotting, Western; D002467:Cell Nucleus / Q000378:metabolism*; D002478:Cells, Cultured; D018385:Centrosome / Q000378:metabolism; D005326:Fetal Proteins / Q000235:genetics / Q000378:metabolism*; D000080865:Formins; D020868:Gene Silencing; D057809:HEK293 Cells; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D008840:Microfilament Proteins / Q000378:metabolism*; D041681:NIH 3T3 Cells; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009685:Nuclear Envelope / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding
chemical_list: D000199:Actins; C120021:FHOD1 protein, human; D005326:Fetal Proteins; D000080865:Formins; D008565:Membrane Proteins; D008840:Microfilament Proteins; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; C485904:SYNE2 protein, human