PMID- 10788500
OWN - NLM
STAT- MEDLINE
DCOM- 20000601
LR  - 20210209
IS  - 0021-9258 (Print)
IS  - 0021-9258 (Linking)
VI  - 275
IP  - 18
DP  - 2000 May 5
TI  - Overexpression of C-terminal Src kinase blocks 14, 15-epoxyeicosatrienoic 
      acid-induced tyrosine phosphorylation and mitogenesis.
PG  - 13789-92
AB  - We have previously reported that 14,15-epoxyeicosatrienoic acid (14, 15-EET) is a 
      potent mitogen for the renal epithelial cell line, LLCPKcl4. This mitogenic 
      effect is dependent upon activation of a protein-tyrosine kinase cascade that 
      results in activation of mitogen-activated protein kinase and 
      phosphatidylinositol 3-kinase. Because of suggestive evidence that 14,15-EET also 
      activated Src in these cells, we stably transfected LLCPKcl4 with an expression 
      construct of the C-terminal Src kinase (CSK), which inhibits Src family kinase 
      activity. In vitro Src kinase activity assays confirmed that in empty 
      vector-transfected cells (Vector cells), 14, 15-EET increased Src kinase 
      activity, while in clones overexpressing CSK mRNA and immunoreactive protein (CSK 
      cells), 14,15-EET-induced activation of Src was almost completely blocked (94% 
      inhibition). Of interest, epidermal growth factor (EGF) and fetal bovine serum 
      (FBS) also increased Src activity in Vector cells, but not in CSK cells, further 
      confirming the ability of CSK overexpression to prevent Src activation. CSK cells 
      failed to increase [(3)H]thymidine incorporation in response to exogenous 
      14,15-EET. In contrast, both EGF and FBS significantly increased [(3)H]thymidine 
      incorporation in CSK cells. Immunoprecipitation with anti-phosphotyrosine 
      antibodies and immunoblotting with an antibody against extracellular 
      signal-regulated kinase (ERK) indicated that in CSK cells, 14,15-EET failed to 
      activate ERK1 and ERK2; however, EGF- and FBS-induced activation of ERKs was not 
      different from that seen in Vector cells. In Vector cells, the 
      14,15-EET-stimulated tyrosine phosphorylation of ERKs was blocked by pretreatment 
      with 1 microm PP2, a selective inhibitor of Src kinases. The present study 
      demonstrates that 14, 15-EET exerts its mitogenic effects predominantly through a 
      Src kinase-mediated pathway, which is the most upstream signaling step determined 
      to date in the 14,15-EET-activated tyrosine kinase cascade in renal epithelial 
      cells.
FAU - Chen, J K
AU  - Chen JK
AD  - Department of Medicine, Vanderbilt University, Nashville, Tennessee 37232, USA.
FAU - Capdevila, J
AU  - Capdevila J
FAU - Harris, R C
AU  - Harris RC
LA  - eng
GR  - DK38226/DK/NIDDK NIH HHS/United States
PT  - Journal Article
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - J Biol Chem
JT  - The Journal of biological chemistry
JID - 2985121R
RN  - 42HK56048U (Tyrosine)
RN  - 81276-03-1 (14,15-epoxy-5,8,11-eicosatrienoic acid)
RN  - EC 2.7.10.2 (src-Family Kinases)
RN  - FC398RK06S (8,11,14-Eicosatrienoic Acid)
SB  - IM
MH  - 8,11,14-Eicosatrienoic Acid/*analogs & derivatives/metabolism/pharmacology
MH  - Animals
MH  - Cattle
MH  - Cell Line
MH  - *Mitosis/drug effects/genetics
MH  - Phosphorylation/drug effects
MH  - Signal Transduction/drug effects
MH  - Tyrosine/metabolism
MH  - src-Family Kinases/*biosynthesis/genetics
EDAT- 2000/05/02 09:00
MHDA- 2000/06/03 09:00
CRDT- 2000/05/02 09:00
PHST- 2000/05/02 09:00 [pubmed]
PHST- 2000/06/03 09:00 [medline]
PHST- 2000/05/02 09:00 [entrez]
AID - S0021-9258(19)80751-2 [pii]
AID - 10.1074/jbc.275.18.13789 [doi]
PST - ppublish
SO  - J Biol Chem. 2000 May 5;275(18):13789-92. doi: 10.1074/jbc.275.18.13789.