RGD Reference Report - Roles of protein kinase C, Ca2+, Pyk2, and c-Src in agonist activation of rat lacrimal gland p42/p44 MAPK. - Rat Genome Database

Send us a Message



Submit Data |  Help |  Video Tutorials |  News |  Publications |  Download |  REST API |  Citing RGD |  Contact   

Roles of protein kinase C, Ca2+, Pyk2, and c-Src in agonist activation of rat lacrimal gland p42/p44 MAPK.

Authors: Hodges, RR  Rios, JD  Vrouvlianis, J  Ota, I  Zoukhri, D  Dartt, DA 
Citation: Hodges RR, etal., Invest Ophthalmol Vis Sci. 2006 Aug;47(8):3352-9.
RGD ID: 1642615
Pubmed: PMID:16877402   (View Abstract at PubMed)
DOI: DOI:10.1167/iovs.06-0028   (Journal Full-text)

PURPOSE: Although p42/p44 mitogen-activated protein kinase (MAPK) negatively modulates protein secretion stimulated by cholinergic and alpha(1D)-adrenergic agonists, it does not play a role in epidermal growth factor (EGF)-stimulated protein secretion. Therefore, this study was conducted to determine the roles that protein kinase C (PKC), intracellular Ca(2+) ([Ca(2+)](i)), and nonreceptor tyrosine kinases Pyk2 and Src play in the activation of agonist- and EGF-stimulated MAPK activation. METHODS: Lacrimal gland acini were isolated by collagenase digestion and incubated with phorbol 12-myristate 13-acetate (PMA) to activate PKC or ionomycin, a Ca(2+) ionophore. Acini were preincubated with the PKC inhibitors calphostin C or Ro-31-8220, EGTA to chelate Ca(2+), or the c-Src inhibitor PP1 before stimulation with the cholinergic agonist carbachol, the alpha(1D)-adrenergic agonist phenylephrine, or EGF. Activated MAPK, Pyk2, and c-Src amounts were measured by Western blot analysis. RESULTS: PMA and ionomycin significantly increased the activation of MAPK in a time- and concentration-dependent manner. Inhibition of PKC partially inhibited carbachol-stimulated MAPK activation while completely inhibiting phenylephrine- and EGF-stimulated MAPK activation. Chelation of Ca(2+) also partially inhibited carbachol-stimulated MAPK with no effect on phenylephrine- and EGF-stimulated MAPK activation. Carbachol increased the phosphorylation of Pyk2 on tyrosine 402 and c-src on tyrosine 416 in a time-dependent manner. The c-src inhibitor PP1 inhibited carbachol-stimulated phosphorylation of Pyk2. CONCLUSIONS: It was concluded that cholinergic agonists use Ca(2+) and PKC to phosphorylate Pyk2 and c-Src, which subsequently stimulate MAPK activity. In contrast, alpha(1D)-adrenergic agonists and EGF do not use Pyk2 and Src but do use PKC to activate MAPK.

Gene Ontology Annotations    Click to see Annotation Detail View

Biological Process
TermQualifierEvidenceWithReferenceNotesSourceOriginal Reference(s)
response to organonitrogen compound  IEP 1642615 RGD 

Objects Annotated

Genes (Rattus norvegicus)
Ptk2b  (protein tyrosine kinase 2 beta)


Additional Information