Protein kinases induced by osmotic stresses and elicitor molecules in tobacco cell suspensions: two crossroad MAP kinases and one osmoregulation-specific protein kinase.
Two protein kinases displaying mitogen-activated protein kinase (MAPK) properties are activated both by an hypoosmotic stress and by oligogalacturonides in tobacco cell suspensions [Cazalé et al. (1999) Plant J. 19, 297-307]. Using specific antibodies, they were identified as the salicylic acid-induced protein kinase (SIPK) and wound-induced protein kinase (WIPK). The SIPK was also activated by an hyperosmotic stress, indicating that the same kinase may play a role both in hypo- and hyperosmotic signalling pathways, in addition to its involvement in the transduction of elicitor signals. Using immunoprecipitation followed by two-dimensional in-gel kinase assay, three molecular forms of the SIPK were observed, suggesting that additional modifications of the activated kinase may occur. In contrast to WIPK and SIPK, which are located at the crossroad of several transduction pathways initiated by elicitor or osmotic stimuli, a 44 kDa kinase, that would not belong to the MAPK family, appeared more specific to osmotic stress.
Droillard
M J
MJ
Institut des Sciences Végétales, UPR 40, CNRS, 1 Av. de la Terrasse, 91198 Cedex, Gif s/Yvette, France.
Thibivilliers
S
S
Cazalé
A C
AC
Barbier-Brygoo
H
H
Laurière
C
C
D000906:Antibodies / Q000276:immunology; D015153:Blotting, Western; D002478:Cells, Cultured; D004789:Enzyme Activation / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D007526:Isoelectric Point; D020928:Mitogen-Activated Protein Kinases / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D008970:Molecular Weight; D009844:Oligosaccharides / Q000494:pharmacology*; D009994:Osmolar Concentration; D010766:Phosphorylation; D010940:Plant Proteins; D010947:Plants, Toxic; D011233:Precipitin Tests; D011494:Protein Kinases / Q000737:chemistry / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D013997:Time Factors; D014026:Nicotiana / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology*; D014574:Uronic Acids / Q000494:pharmacology*
D000906:Antibodies; D009844:Oligosaccharides; D010940:Plant Proteins; D014574:Uronic Acids; D011494:Protein Kinases; D020928:Mitogen-Activated Protein Kinases; C106405:SA-induced protein kinase; C113423:WIPK protein, Nicotiana tabacum