The interaction of SV40 small tumor antigen with protein phosphatase 2A stimulates the map kinase pathway and induces cell proliferation
E Sontag, S Fedorov, C Kamibayashi, D Robbins… - Cell, 1993 - cell.com
E Sontag, S Fedorov, C Kamibayashi, D Robbins, M Cobb, M Mumby
Cell, 1993•cell.comInteraction with SV40 small tumor antigen (small t) compromised the ability of multimeric
protein phosphatase 2A to inactivate the mitogen-activated protein kinase ERKl and the
mitogen-activated protein kinase kinase MEKl. Transient expression of small t in CV-1 cells
activated MEK and ERK but did not affect Raf activity. Small t stimulated the growth of
quiescent CV-1 cells almost as effectively as did serum. Coexpression of kinase-deficient
ERK2 blocked most, but not all, of the proliferation caused by small t. Activation of the …
protein phosphatase 2A to inactivate the mitogen-activated protein kinase ERKl and the
mitogen-activated protein kinase kinase MEKl. Transient expression of small t in CV-1 cells
activated MEK and ERK but did not affect Raf activity. Small t stimulated the growth of
quiescent CV-1 cells almost as effectively as did serum. Coexpression of kinase-deficient
ERK2 blocked most, but not all, of the proliferation caused by small t. Activation of the …
Summary
Interaction with SV40 small tumor antigen (small t) compromised the ability of multimeric protein phosphatase 2A to inactivate the mitogen-activated protein kinase ERKl and the mitogen-activated protein kinase kinase MEKl. Transient expression of small t in CV-1 cells activated MEK and ERK but did not affect Raf activity. Small t stimulated the growth of quiescent CV-1 cells almost as effectively as did serum. Coexpression of kinase-deficient ERK2 blocked most, but not all, of the proliferation caused by small t. Activation of the mitogen-activated protein kinase pathway and stimulation of cell growth were dependent on the interaction of small t with protein phosphatase 2A. These findings indicate that SV40 small t is capable of inducing cell growth through blockade of protein phosphatase and deregulation of the mitogen-activated protein kinase cascade.
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