Extra-cellular matrix proteins induce re-distribution of alpha-actinin-1 and alpha-actinin-4 in A431 cells.
Alpha-actinins are actin-binding proteins of non-muscle cells, which can participate in the regulation of transcription factor activity. We describe the distribution of alpha-actinin-1 and -4 depending on different actin cytoskeleton formed as a result of cell adhesion to extracellular matrix proteins, such as fibronectin and laminin 2/4. Immunofluorescent studies show a difference in the distribution of alpha-actinin and -4. Both isoforms localise along stress-fibres, but alpha-actinin-1 localises in the perinuclear region more abundantly than alpha-actinin-4. Western blot analysis demonstrated existence of truncated forms of both isoforms. Truncated alpha-actinin-1 appears in cells spread on fibronectin or laminin. Cell spreading also correlated with more tight association of alpha-actinin-4 with chromatin. Basing on our previous finding of an interaction of alpha-actinin-4 with p65 subunit of the NF-kappaB, we checked the possible influence of immobilised ligands on its redistribution in nuclear complexes containing p65. alpha-Actinin-4 seems to be present in some but not all nuclear complexes containing p65. Immobilised ligands may affect the interaction of alpha-actinin-4/p65 complexes with chromatin. The data suggest that adhesion to extra-cellular matrix may interfere in cellular reactions mediated by alpha-actinin-1 and -4.
Bolshakova
Anastasia
A
Department of Cell Cultures, Institute of Cytology, Tikhoretsky Avenue 4, St. Petersburg 194064, Russian Federation.
Petukhova
Olga
O
Turoverova
Lidia
L
Tentler
Dmitri
D
Babakov
Vladimir
V
Magnusson
Karl-Eric
KE
Pinaev
George
G
D000185:Actinin / Q000378:metabolism*; D015153:Blotting, Western; D002294:Carcinoma, Squamous Cell / Q000378:metabolism*; D002448:Cell Adhesion; D003593:Cytoplasm; D003599:Cytoskeleton / Q000378:metabolism*; D005353:Fibronectins / Q000378:metabolism*; D006801:Humans; D047468:Immunoprecipitation; D007797:Laminin / Q000378:metabolism*; D008840:Microfilament Proteins / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism; D013347:Subcellular Fractions; D014407:Tumor Cells, Cultured
C111453:ACTN4 protein, human; D005353:Fibronectins; D007797:Laminin; D008840:Microfilament Proteins; D016328:NF-kappa B; D000185:Actinin