In Vitro MAP kinase assay 9/1998
- Deprive PC12 cells overnight in 4ml of DMEM+1% BSA+1%Glu/AA
- stimulate cells with 100ng/ml for 10 minutes
- Lyse cells in 600ml lysis buffer:
- 50mM HEPES, pH 7.5
- 150mM NaCL
- 1.5mM MgCl2
- 1mM EGTA
- 0.1% Triton X-100
- 105 glycerol
- 1mM Na3VO4,1mM PMSF
- 10mg/ml aprotinin
- 10mg/ml leupeptin
- Immunoprecipitate with ant-ERK2 (Santa Cruz, SC-154, 1:100 dilution, 0.5mg anti- ERK2 per condition)
- Wash 3x1ml lysis buffer, 2x 0.5ml kinase buffer (50mM HEPES, pH 7.4, 10mM MgCl2, 0.5mM DTT, 5mM Na3VO4)
- HEPES (50mM pH 7.4) 10ml
- MgCl2 (2M) 50ml
- DTT (1M) 5ml
- Na3VO4 500ml
- Add 10-20mg GST-SH2-Bb to anti-ERK2 immunoprecipitates (could be reduced to 1mg/reaction)
- Add 50ml reaction buffer, mix at room temp for 30 minutes (mix every 10 min)
Reaction buffer:
Kinase Buffer 700ml
Cold ATP 3ml ([final]=20-100mM)(not necessary)
PI 1ml([final]=10mM)
g-32PATP (150mCi/ml) 1.3ml (10mCi per reaction)
- Add 400ml lysis buffer and mix, spin down, transfer the supernatant to a fresh tube
- add 50ml glutathione-agarose beads, rotate in cold room for 1-2 hrs
- wash beads with 2x 1ml lysis buffer, 2x 0.5 ml thrombin cleavage buffer (TCB:50mM Tris-HCl, pH 8.0, 150mM NaCl, 2.5mM CaCl2, 0.1%b-ME)
- Tris-HCl, pH 8.0 10ml
- NaCl 300ml
- CaCl2 25ml
- B-ME 10ml
- Add 110 ml TCB containing 1U thrombin (Sigma, T3010), rotate at Room temp 1 hr
- Add 30ml 5x loading buffer, boil 5 minutes, run 7.5% SDS-PAGE
- transfer proteins to nitrocellulose membrane
- autoradiography for 1-3 days
- immunoblot the membrane with anti-SH2-B