title: Lamin A/C-dependent localization of Nesprin-2, a giant scaffolder at the nuclear envelope.
abstract: The vertebrate proteins Nesprin-1 and Nesprin-2 (also referred to as Enaptin and NUANCE) together with ANC-1 of Caenorhabditis elegans and MSP-300 of Drosophila melanogaster belong to a novel family of alpha-actinin type actin-binding proteins residing at the nuclear membrane. Using biochemical techniques, we demonstrate that Nesprin-2 binds directly to emerin and the C-terminal common region of lamin A/C. Selective disruption of the lamin A/C network in COS7 cells, using a dominant negative lamin B mutant, resulted in the redistribution of Nesprin-2. Furthermore, using lamin A/C knockout fibroblasts we show that lamin A/C is necessary for the nuclear envelope localization of Nesprin-2. In normal skin where lamin A/C is differentially expressed, strong Nesprin-2 expression was found in all epidermal layers, including the basal layer where only lamin C is present. This indicates that lamin C is sufficient for proper Nesprin-2 localization at the nuclear envelope. Expression of dominant negative Nesprin-2 constructs and knockdown studies in COS7 cells revealed that the presence of Nesprin-2 at the nuclear envelope is necessary for the proper localization of emerin. Our data imply a scaffolding function of Nesprin-2 at the nuclear membrane and suggest a potential involvement of this multi-isomeric protein in human disease.
authors.affiliation: Center for Biochemistry, Medical Faculty, University of Cologne, 50931 Cologne, Germany.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Libotte
authors.forename: Hafida
authors.initials: H
authors.lastname: Zaim
authors.forename: Sabu
authors.initials: S
authors.lastname: Abraham
authors.forename: V C
authors.initials: VC
authors.lastname: Padmakumar
authors.forename: Maria
authors.initials: M
authors.lastname: Schneider
authors.forename: Wenshu
authors.initials: W
authors.lastname: Lu
authors.forename: Martina
authors.initials: M
authors.lastname: Munck
authors.forename: Christopher
authors.initials: C
authors.lastname: Hutchison
authors.forename: Manfred
authors.initials: M
authors.lastname: Wehnert
authors.forename: Birthe
authors.initials: B
authors.lastname: Fahrenkrog
authors.forename: Ursula
authors.initials: U
authors.lastname: Sauder
authors.forename: Ueli
authors.initials: U
authors.lastname: Aebi
authors.forename: Angelika A
authors.initials: AA
authors.lastname: Noegel
authors.forename: Iakowos
authors.initials: I
authors.lastname: Karakesisoglou
mesh_terms: D000818:Animals; D015153:Blotting, Western; D019556:COS Cells; D017173:Caenorhabditis elegans; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D004331:Drosophila melanogaster; D005799:Genes, Dominant; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D015151:Immunoblotting; D007150:Immunohistochemistry; D047468:Immunoprecipitation; D066298:In Vitro Techniques; D034904:Lamin Type A / Q000096:biosynthesis*; D008565:Membrane Proteins / Q000378:metabolism; D008840:Microfilament Proteins / Q000096:biosynthesis*; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D008957:Models, Genetic; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000096:biosynthesis*; D009685:Nuclear Envelope / Q000378:metabolism*; D009687:Nuclear Proteins / Q000096:biosynthesis*; D010957:Plasmids / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D034741:RNA, Small Interfering / Q000378:metabolism; D013946:Thymopoietins / Q000378:metabolism; D014162:Transfection; D020798:Two-Hybrid System Techniques
chemical_list: D034904:Lamin Type A; D008565:Membrane Proteins; D008840:Microfilament Proteins; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D034741:RNA, Small Interfering; C485904:SYNE2 protein, human; D013946:Thymopoietins; C092710:emerin; C440308:lamin C; D005982:Glutathione Transferase