Protein phosphatase 2A regulatory subunit Bbeta promotes MAP kinase-mediated migration of A431 cells.
OBJECTIVE
Phosphatases are involved in regulation of MAP kinase (MAPK). A431 cells migrate on collagen after EGF stimulation using MAPK. To clarify the involvement of PP2A in this MAPK-dependent migration, the expression of an isoform of the B regulatory subunit was inhibited.


METHODS
An antisense sequence corresponding to Bbeta cDNA was transfected into A431 cells. Their migratory activity on collagen was examined using Transwell, and MAPK phosphorylation and phosphatase activity were measured, and the results were compared with those obtained with mock-transfected cells.


RESULTS
Antisense-transfected cells showed less Bbeta protein and phosphatase activity than mock-transfected controls. Migration of antisense-transfected cells showed a low response to EGF. The response of MAPK phosphorylation of antisense-transfected cells to EGF stimulation and adhesion to collagen in the presence or absence of EGF were markedly decreased. Phosphatase activity of PP2A-Bbeta also did not respond to EGF, collagen or EGF plus collagen, and remained at low levels.


CONCLUSIONS
These results suggested that PP2A-Bbeta promotes cell migration through the MAPK cascade.
Nakada
Natsuko
N
Department of Laboratory Sciences, School of Health Sciences, Kanazawa University Faculty of Medicine, Japan.
Kuroda
Kanako
K
Kawahara
Ei
E
D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D003094:Collagen / Q000494:pharmacology; D004815:Epidermal Growth Factor / Q000494:pharmacology; D022001:Focal Adhesions; D015870:Gene Expression; D006801:Humans; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D010749:Phosphoprotein Phosphatases / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D020033:Protein Isoforms; D054648:Protein Phosphatase 2
C432785:PPP2R1B protein, human; D020033:Protein Isoforms; D004815:Epidermal Growth Factor; D003094:Collagen; D020928:Mitogen-Activated Protein Kinases; D010749:Phosphoprotein Phosphatases; D054648:Protein Phosphatase 2