title: The scaffolding protein IQGAP1 co-localizes with actin at the cytoplasmic face of the nuclear envelope: implications for cytoskeletal regulation.
abstract: IQGAP1 is an important cytoskeletal regulator, known to act at the plasma membrane to bundle and cap actin filaments, and to tether the cortical actin meshwork to microtubules via plus-end binding proteins. Here we describe the novel subcellular localization of IQGAP1 at the cytoplasmic face of the nuclear envelope, where it co-located with F-actin. The IQGAP1 and F-actin staining overlapped that of microtubules at the nuclear envelope, revealing a pattern strikingly similar to that observed at the plasma membrane. In detergent-extracted cells IQGAP1 was retained at cytoskeletal structures at the nuclear envelope. This finding has new implications for involvement of IQGAP1 in cell polarization and migration events and potentially in cell cycle-associated nuclear envelope assembly/disassembly.
authors.affiliation: Westmead Institute for Cancer Research; University of Sydney; Westmead Millennium Institute at Westmead Hospital; Westmead, Australia.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Johnson
authors.affiliation: Westmead Institute for Cancer Research; University of Sydney; Westmead Millennium Institute at Westmead Hospital; Westmead, Australia.
authors.forename: Beric R
authors.initials: BR
authors.lastname: Henderson
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism*; D000199:Actins / Q000378:metabolism*; D000818:Animals; D002478:Cells, Cultured; D003593:Cytoplasm / Q000378:metabolism*; D019073:HT29 Cells; D006801:Humans; D061986:MCF-7 Cells; D051379:Mice; D041681:NIH 3T3 Cells; D009685:Nuclear Envelope / Q000378:metabolism*; D020703:ras GTPase-Activating Proteins / Q000378:metabolism*
chemical_list: D000199:Actins; C101203:IQ motif containing GTPase activating protein 1; D020703:ras GTPase-Activating Proteins