title: Arachidonic acid induces ERK activation via Src SH2 domain association with the epidermal growth factor receptor.
abstract: Within the kidney, angiotensin II type 2 (AT(2)) receptor mediates phospholipase A(2) (PLA(2)) activation, arachidonic acid release, epidermal growth factor (EGF) receptor transactivation, and mitogen-activated protein kinase activation. Arachidonic acid mimics this transactivation by an undetermined mechanism. The role of c-Src in mediating angiotensin II and arachidonic acid signaling was determined by employing immunocomplex kinase assay, Western blotting analysis, and protein immunoblotting on co-precipitated EGF receptor (EGFR) proteins and agarose conjugates of glutathione S-transferase fusion proteins containing the c-Src homology 2 (SH2) and SH3 domains. Angiotensin II induced extracellular signal-regulated kinase (ERK) activation in primary cultures of rabbit proximal tubule cells via the activation of c-Src and association of the EGFR with the c-Src SH2 domain, effects that were mimicked by arachidonic acid and its inactive analogue eicosatetraynoic acid. Inhibition of PLA(2) by mepacrine and methyl arachidonyl fluorophosphate, AT(2) receptor by PD123319, Src family kinases by, 1-(tert-butyl)-3-(4-chlorophenyl)-4-aminopyrazolo[3,4-d] pyrimidine (PP2) and c-Src by overexpression of a dominant-negative mutant of c-Src abrogated these effects. However, inhibitors of arachidonic acid metabolic pathways did not block these effects. The present work provides a new and novel paradigm for transactivation of a kinase receptor linked to a fatty acid, which may apply to activation of a variety of phospholipases and accompanying arachidonic acid release.
authors.affiliation: Department of Natural Sciences, The University of Michigan-Dearborn, 48128, USA. ldalexa@umd.umich.edu
authors.forename: L D
authors.initials: LD
authors.lastname: Alexander
authors.forename: Y
authors.initials: Y
authors.lastname: Ding
authors.forename: S
authors.initials: S
authors.lastname: Alagarsamy
authors.forename: X-L
authors.initials: XL
authors.lastname: Cui
authors.forename: J G
authors.initials: JG
authors.lastname: Douglas
mesh_terms: D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D016718:Arachidonic Acid / Q000494:pharmacology*; D002478:Cells, Cultured; D016895:Culture Media, Serum-Free; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D066246:ErbB Receptors / Q000235:genetics / Q000378:metabolism*; D005982:Glutathione Transferase / Q000378:metabolism; D007687:Kidney Tubules, Proximal / Q000166:cytology / Q000201:enzymology*; D007700:Kinetics; D008297:Male; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D016392:Proto-Oncogene Proteins pp60(c-src) / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D011743:Pyrimidines / Q000494:pharmacology; D011799:Quinazolines; D011817:Rabbits; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015533:Transcriptional Activation / Q000187:drug effects; D020032:Tyrphostins / Q000494:pharmacology
chemical_list: C412373:AG 1879; D016895:Culture Media, Serum-Free; D004791:Enzyme Inhibitors; D011743:Pyrimidines; D011799:Quinazolines; D011993:Recombinant Fusion Proteins; D020032:Tyrphostins; D000804:Angiotensin II; C101044:RTKI cpd; D016718:Arachidonic Acid; D005982:Glutathione Transferase; D066246:ErbB Receptors; D016392:Proto-Oncogene Proteins pp60(c-src); D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases