title: Cytoskeletal interactions at the nuclear envelope mediated by nesprins.
abstract: Nesprin-1 is a giant tail-anchored nuclear envelope protein composed of an N-terminal F-actin binding domain, a long linker region formed by multiple spectrin repeats and a C-terminal transmembrane domain. Based on this structure, it connects the nucleus to the actin cytoskeleton. Earlier reports had shown that Nesprin-1 binds to nuclear envelope proteins emerin and lamin through C-terminal spectrin repeats. These repeats can also self-associate. We focus on the N-terminal Nesprin-1 sequences and show that they interact with Nesprin-3, a further member of the Nesprin family, which connects the nucleus to the intermediate filament network. We show that upon ectopic expression of Nesprin-3 in COS7 cells, which are nearly devoid of Nesprin-3 in vitro, vimentin filaments are recruited to the nucleus and provide evidence for an F-actin interaction of Nesprin-3 in vitro. We propose that Nesprins through interactions amongst themselves and amongst the various Nesprins form a network around the nucleus and connect the nucleus to several cytoskeletal networks of the cell.
authors.affiliation: Institute of Biochemistry I, Medical Faculty, University of Cologne, Joseph-Stelzmann-Strasse 52, 50931 Cologne, Germany.
authors.forename: Surayya
authors.initials: S
authors.lastname: Taranum
authors.forename: Ilknur
authors.initials: I
authors.lastname: Sur
authors.forename: Rolf
authors.initials: R
authors.lastname: Müller
authors.forename: Wenshu
authors.initials: W
authors.lastname: Lu
authors.forename: R N
authors.initials: RN
authors.lastname: Rashmi
authors.forename: Martina
authors.initials: M
authors.lastname: Munck
authors.forename: Sascha
authors.initials: S
authors.lastname: Neumann
authors.forename: Iakowos
authors.initials: I
authors.lastname: Karakesisoglou
authors.forename: Angelika A
authors.initials: AA
authors.lastname: Noegel