title: Diacylglycerol kinase-alpha phosphorylation by Src on Y335 is required for activation, membrane recruitment and Hgf-induced cell motility.
abstract: 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-alpha, 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-alpha 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-alpha 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-alpha 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-alpha 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.
authors: Department of Medical Sciences, University Amedeo Avogadro of Piemonte Oriental, Novara, Italy.
authors: G
authors: G
authors: Baldanzi
authors: S
authors: S
authors: Cutrupi
authors: F
authors: F
authors: Chianale
authors: V
authors: V
authors: Gnocchi
authors: E
authors: E
authors: Rainero
authors: P
authors: P
authors: Porporato
authors: N
authors: N
authors: Filigheddu
authors: W J
authors: WJ
authors: van Blitterswijk
authors: O
authors: O
authors: Parolini
authors: F
authors: F
authors: Bussolino
authors: F
authors: F
authors: Sinigaglia
authors: A
authors: A
authors: Graziani
mesh_terms: D000818:Animals; D019556:COS Cells / Q000378:metabolism; D002450:Cell Communication; D002462:Cell Membrane / Q000378:metabolism*; D002465:Cell Movement; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D019852:Diacylglycerol Kinase / Q000378:metabolism*; D004285:Dogs; D004789:Enzyme Activation; D017228:Hepatocyte Growth Factor / Q000494:pharmacology*; D006801:Humans; D007668:Kidney / Q000166:cytology / Q000378:metabolism; D009227:Myristic Acids / Q000737:chemistry*; D015688:Oncogene Protein pp60(v-src) / Q000502:physiology*; D010766:Phosphorylation; D011392:Proline / Q000378:metabolism; D015398:Signal Transduction; D014443:Tyrosine / Q000378:metabolism*
chemical_list: D009227:Myristic Acids; D014443:Tyrosine; D017228:Hepatocyte Growth Factor; D011392:Proline; D019852:Diacylglycerol Kinase; D015688:Oncogene Protein pp60(v-src)