title: Convergence of eicosanoid and integrin biology: Role of Src in 12-LOX activation.
abstract: 12-Lipoxygenase (12-LOX) metabolizes arachidonic acid to 12(S)-hydroxyeicosatetraenoic acid, or 12(S)-HETE, a proinflammatory bioactive lipid implicated in tumor angiogenesis, growth, and metastasis. The mechanisms underlying 12-LOX-mediated signaling in cancer progression are still ill-defined. In the present study we demonstrate that 12-LOX phosphorylation and subsequent enzymatic activity occurs after integrin β4 stimulation and Src kinase recruitment to the integrin subunit. Inhibition of Src activity by PP2 or Src dominant-negative mutants reduced 12-LOX tyrosine phosphorylation and 12(S)-HETE production in response to integrin β4 stimulation in A431 cells. The pertinent Src-targeted residues for 12-LOX activity were mapped to Y19 and Y614, where 12-LOX mutants Y19F and Y614F showed 70% less enzymatic activity. Furthermore, we have shown that the 12-LOX activity modulated by these residues impacts migration. To our knowledge, this is the first report that c-Src kinase activity is required for β4-integrin-mediated phosphorylation of 12-LOX.
authors.affiliation: Departments of Pathology-Bioactive Lipids Research Program, Detroit, MI 48202, United States. Electronic address: akd37@pitt.edu.
authors.forename: Ashok-Kumar
authors.initials: AK
authors.lastname: Dilly
authors.affiliation: Departments of Radiation Oncology, Wayne State University School of Medicine, Detroit, MI 48202, United States. Electronic address: ktang@med.wayne.edu.
authors.forename: Keqin
authors.initials: K
authors.lastname: Tang
authors.affiliation: Departments of Pathology-Bioactive Lipids Research Program, Detroit, MI 48202, United States. Electronic address: guoyande@yahoo.com.
authors.forename: Yande
authors.initials: Y
authors.lastname: Guo
authors.affiliation: Departments of Pathology-Bioactive Lipids Research Program, Detroit, MI 48202, United States. Electronic address: sjoshi@tartiscorp.com.
authors.forename: Sangeeta
authors.initials: S
authors.lastname: Joshi
authors.affiliation: Departments of Pathology-Bioactive Lipids Research Program, Detroit, MI 48202, United States. Electronic address: pre2@pitt.edu.
authors.forename: Prasanna
authors.initials: P
authors.lastname: Ekambaram
authors.affiliation: Departments of Pathology-Bioactive Lipids Research Program, Detroit, MI 48202, United States. Electronic address: maddipati@wayne.edu.
authors.forename: Krishna Rao
authors.initials: KR
authors.lastname: Maddipati
authors.affiliation: Departments of Pathology-Bioactive Lipids Research Program, Detroit, MI 48202, United States. Electronic address: aa9873@wayne.edu.
authors.forename: Yinlong
authors.initials: Y
authors.lastname: Cai
authors.affiliation: Departments of Pathology-Bioactive Lipids Research Program, Detroit, MI 48202, United States. Electronic address: stucker@med.wayne.edu.
authors.forename: Stephanie C
authors.initials: SC
authors.lastname: Tucker
authors.affiliation: Departments of Pathology-Bioactive Lipids Research Program, Detroit, MI 48202, United States; Departments of Karmanos Cancer Institute, Detroit, MI 48202, United States. Electronic address: k.v.honn@wayne.edu.
authors.forename: Kenneth V
authors.initials: KV
authors.lastname: Honn
mesh_terms: D019377:12-Hydroxy-5,8,10,14-eicosatetraenoic Acid / Q000378:metabolism*; D001092:Arachidonate 12-Lipoxygenase / Q000378:metabolism*; D045744:Cell Line, Tumor; D002465:Cell Movement; D057809:HEK293 Cells; D006801:Humans; D039663:Integrin beta4 / Q000737:chemistry / Q000378:metabolism*; D019061:src-Family Kinases / Q000378:metabolism*
chemical_list: C059834:ITGB4 protein, human; D039663:Integrin beta4; D019377:12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; D001092:Arachidonate 12-Lipoxygenase; D019061:src-Family Kinases
keywords: 12-Lipoxygenase phosphorylation; C-Src kinase; Cell migration; β4 Integrin