title: Mammalian microtubule P-body dynamics are mediated by nesprin-1.
abstract: Nesprins are a multi-isomeric family of spectrin-repeat (SR) proteins, predominantly known as nuclear envelope scaffolds. However, isoforms that function beyond the nuclear envelope remain poorly examined. Here, we characterize p50(Nesp1), a 50-kD isoform that localizes to processing bodies (PBs), where it acts as a microtubule-associated protein capable of linking mRNP complexes to microtubules. Overexpression of dominant-negative p50(Nesp1) caused Rck/p54, but not GW182, displacement from microtubules, resulting in reduced PB movement and cross talk with stress granules (SGs). These cells disassembled canonical SGs induced by sodium arsenite, but not those induced by hydrogen peroxide, leading to cell death and revealing PB-microtubule attachment is required for hydrogen peroxide-induced SG anti-apoptotic functions. Furthermore, p50(Nesp1) was required for miRNA-mediated silencing and interacted with core miRISC silencers Ago2 and Rck/p54 in an RNA-dependent manner and with GW182 in a microtubule-dependent manner. These data identify p50(Nesp1) as a multi-functional PB component and microtubule scaffold necessary for RNA granule dynamics and provides evidence for PB and SG micro-heterogeneity.
authors.affiliation: Cardiovascular Division, BHF Centre of Excellence, James Black Centre, King's College London, London SE5 9NU, England, UK.
authors.forename: Dipen
authors.initials: D
authors.lastname: Rajgor
authors.affiliation: Cardiovascular Division, BHF Centre of Excellence, James Black Centre, King's College London, London SE5 9NU, England, UK.
authors.forename: Jason A
authors.initials: JA
authors.lastname: Mellad
authors.affiliation: Cardiovascular Division, BHF Centre of Excellence, James Black Centre, King's College London, London SE5 9NU, England, UK.
authors.forename: Daniel
authors.initials: D
authors.lastname: Soong
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Calgary, Calgary T2N 4N1, Alberta, Canada.
authors.forename: Jerome B
authors.initials: JB
authors.lastname: Rattner
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Calgary, Calgary T2N 4N1, Alberta, Canada.
authors.forename: Marvin J
authors.initials: MJ
authors.lastname: Fritzler
authors.affiliation: Cardiovascular Division, BHF Centre of Excellence, James Black Centre, King's College London, London SE5 9NU, England, UK cathy.shanahan@kcl.ac.uk.
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Shanahan
mesh_terms: D000818:Animals; D018053:Arsenites / Q000494:pharmacology; D045744:Cell Line, Tumor; D003594:Cytoplasmic Granules / Q000235:genetics / Q000378:metabolism*; D003598:Cytoskeletal Proteins; D020405:Dermis / Q000166:cytology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism*; D055785:Gene Knockdown Techniques; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008322:Mammals; D051379:Mice; D008870:Microtubules / Q000235:genetics / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000378:metabolism*; D032446:Myoblasts / Q000166:cytology / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D012516:Osteosarcoma; D016877:Oxidants / Q000494:pharmacology; D012333:RNA, Messenger / Q000502:physiology; D017670:Sodium Compounds / Q000494:pharmacology; D013312:Stress, Physiological / Q000187:drug effects / Q000502:physiology
chemical_list: D018053:Arsenites; D003598:Cytoskeletal Proteins; D004791:Enzyme Inhibitors; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D016877:Oxidants; D012333:RNA, Messenger; C415465:SYNE1 protein, human; D017670:Sodium Compounds; C017947:sodium arsenite; D006861:Hydrogen Peroxide