TY - JOUR
T1 - Diacylglycerol kinase-α phosphorylation by Src on Y335 is required for activation, membrane recruitment and Hgf-induced cell motility
AU - Baldanzi, G.
AU - Cutrupi, S.
AU - Chianale, F.
AU - Gnocchi, V.
AU - Rainero, E.
AU - Porporato, P.
AU - Filigheddu, N.
AU - Van Blitterswijk, W. J.
AU - Parolini, O.
AU - Bussolino, F.
AU - Sinigaglia, F.
AU - Graziani, A.
PY - 2008/2/7
Y1 - 2008/2/7
N2 - Diacylglycerol (DAG) kinases (Dgk), which phosphorylate DAG to generate phosphatidic acid, act as either positive or negative key regulators of cell signaling. We previously showed that Src mediates growth factors-induced activation of Dgk-α, whose activity is required for cell motility, proliferation and angiogenesis. Here, we demonstrate that both hepatocytes growth factor (HGF) stimulation and v-Src transformation induce tyrosine phosphorylation of Dgk-α on Y335, through a mechanism requiring its proline-rich C-terminal sequence. Moreover, we show that both proline-rich sequence and phosphorylation of Y335 of Dgk-α mediate: (i) its enzymatic activation, (ii) its ability to interact respectively with SH3 and SH2 domains of Src, (iii) its recruitment to the membrane. In addition, we show that phosphorylation of Dgk-α on Y335 is required for HGF-induced motility, while its constitutive recruitment at the membrane by myristylation is sufficient to trigger spontaneous motility in absence of HGF. Providing the first evidence that tyrosine phosphorylation of Dgk-α is required for growth-factors-induced activation and membrane recruitment, these findings underscore its relevance as a rheostat, whose activation is a threshold to elicit growth factors-induced migratory signaling.
AB - Diacylglycerol (DAG) kinases (Dgk), which phosphorylate DAG to generate phosphatidic acid, act as either positive or negative key regulators of cell signaling. We previously showed that Src mediates growth factors-induced activation of Dgk-α, whose activity is required for cell motility, proliferation and angiogenesis. Here, we demonstrate that both hepatocytes growth factor (HGF) stimulation and v-Src transformation induce tyrosine phosphorylation of Dgk-α on Y335, through a mechanism requiring its proline-rich C-terminal sequence. Moreover, we show that both proline-rich sequence and phosphorylation of Y335 of Dgk-α mediate: (i) its enzymatic activation, (ii) its ability to interact respectively with SH3 and SH2 domains of Src, (iii) its recruitment to the membrane. In addition, we show that phosphorylation of Dgk-α on Y335 is required for HGF-induced motility, while its constitutive recruitment at the membrane by myristylation is sufficient to trigger spontaneous motility in absence of HGF. Providing the first evidence that tyrosine phosphorylation of Dgk-α is required for growth-factors-induced activation and membrane recruitment, these findings underscore its relevance as a rheostat, whose activation is a threshold to elicit growth factors-induced migratory signaling.
KW - Cell migration
KW - Diacylglycerol kinase
KW - Hepatocyte growth factor
KW - Signal transduction
KW - Src
KW - Tyrosine kinase
UR - http://www.scopus.com/inward/record.url?scp=38949194934&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=38949194934&partnerID=8YFLogxK
U2 - 10.1038/sj.onc.1210717
DO - 10.1038/sj.onc.1210717
M3 - Article
C2 - 17700527
AN - SCOPUS:38949194934
VL - 27
SP - 942
EP - 956
JO - Oncogene
JF - Oncogene
SN - 0950-9232
IS - 7
ER -