title: RelA/NF-kappaB transcription factor associates with alpha-actinin-4.
abstract: The NF-kappaB/RelA family of transcription factors regulates inducible transcription of a large number of genes in response to diverse stimuli. Little is known, however, about the location of NF-kappaB in the cytoplasm and the transport mechanism to the nucleus. We found that NF-kappaB is associated with the actin-binding protein alpha-actinin-4. NF-kappaB and alpha-actinin-4 co-localized along actin stress fibers and in membrane lamellae in A431 cells. After a 30-min stimulation with EGF or TNF-alpha, alpha-actinin-4 and p65 were found in the nucleus. Disruption of cytoskeleton by cytochalasin D prior to treatment with TNF-alpha led to increase of p65 nuclear translocation. Antibodies to p65 subunit of NF-kappaB co-immunoprecipitated alpha-actinin-4 from A431 cell lysates and nuclear extracts, but alpha-actinin-1 and beta-actin were not found in the precipitates. Affinity chromatography experiments displayed that p65 and p50 subunits of NF-kappaB can bind to matrix-bound chicken gizzard alpha-actinin. We suggest that the alpha-actinin-4 is important for the NF-kappaB nuclear translocation and its functions inside the nucleus.
authors.affiliation: Department of Cell Cultures, Institute of Cytology, St Petersburg, Russian Federation. vbabakov@gmail.com
authors.forename: Vladimir N
authors.initials: VN
authors.lastname: Babakov
authors.forename: Olga A
authors.initials: OA
authors.lastname: Petukhova
authors.forename: Lidia V
authors.initials: LV
authors.lastname: Turoverova
authors.forename: Irina V
authors.initials: IV
authors.lastname: Kropacheva
authors.forename: Dmitri G
authors.initials: DG
authors.lastname: Tentler
authors.forename: Anastasia V
authors.initials: AV
authors.lastname: Bolshakova
authors.forename: Ekaterina P
authors.initials: EP
authors.lastname: Podolskaya
authors.forename: Karl-Eric
authors.initials: KE
authors.lastname: Magnusson
authors.forename: George P
authors.initials: GP
authors.lastname: Pinaev
mesh_terms: D000185:Actinin / Q000378:metabolism*; D021581:Active Transport, Cell Nucleus; D000818:Animals; D045744:Cell Line, Tumor; D002645:Chickens; D003593:Cytoplasm / Q000737:chemistry; D006801:Humans; D008840:Microfilament Proteins / Q000378:metabolism*; D052002:NF-kappa B p50 Subunit / Q000378:metabolism*; D011485:Protein Binding; D022502:Stress Fibers; D051996:Transcription Factor RelA / Q000378:metabolism*
chemical_list: C111453:ACTN4 protein, human; D008840:Microfilament Proteins; D052002:NF-kappa B p50 Subunit; D051996:Transcription Factor RelA; D000185:Actinin