[PDF][PDF] The tumor suppressor DAPK is reciprocally regulated by tyrosine kinase Src and phosphatase LAR

WJ Wang, JC Kuo, W Ku, YR Lee, FC Lin, YL Chang… - Molecular cell, 2007 - cell.com
WJ Wang, JC Kuo, W Ku, YR Lee, FC Lin, YL Chang, YM Lin, CH Chen, YP Huang
Molecular cell, 2007cell.com
Death-associated protein kinase (DAPK) is a calmodulin-regulated serine/threonine kinase
and elicits tumor suppression function through inhibiting cell adhesion/migration and
promoting apoptosis. Despite these biological functions, the signaling mechanisms through
which DAPK is regulated remain largely elusive. Here, we show that the leukocyte common
antigen-related (LAR) tyrosine phosphatase dephosphorylates DAPK at pY491/492 to
stimulate the catalytic, proapoptotic, and antiadhesion/antimigration activities of DAPK …
Summary
Death-associated protein kinase (DAPK) is a calmodulin-regulated serine/threonine kinase and elicits tumor suppression function through inhibiting cell adhesion/migration and promoting apoptosis. Despite these biological functions, the signaling mechanisms through which DAPK is regulated remain largely elusive. Here, we show that the leukocyte common antigen-related (LAR) tyrosine phosphatase dephosphorylates DAPK at pY491/492 to stimulate the catalytic, proapoptotic, and antiadhesion/antimigration activities of DAPK. Conversely, Src phosphorylates DAPK at Y491/492, which induces DAPK intra-/intermolecular interaction and inactivation. Upon EGF stimulation, a rapid Src activation leads to subsequent LAR downregulation, and these two events act in synergism to inactivate DAPK, thereby facilitating tumor cell migration and invasion toward EGF. Finally, DAPK Y491/492 hyperphosphorylation is found in human cancers in which Src activity is aberrantly elevated. These results identify LAR and Src as a DAPK regulator through their reciprocal modification of DAPK Y491/492 residues and establish a functional link of this DAPK-regulatory circuit to tumor progression.
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