Osmotic and glutamate receptor regulation of c-Jun NH(2)-terminal protein kinase in neuroendocrine cells.
Expression of a c-Jun NH(2)-terminal protein kinase (JNK), also known as stress-activated protein kinase (SAPK) in rodents, has been implicated in the ability of cells to respond to a variety of stressors. In nonmammalian cells, JNK participates in the regulation of cell volume in response to hyperosmotic stress. To explore the possibility that JNK may participate in the transduction of osmotic information in mammals, we evaluated the expression of JNK immunoreactivity in neuroendocrine cells of the supraoptic nucleus. Low basal expression of JNK-2 (SAPK-alpha) and JNK-3 (SAPK-beta) was seen in vivo and in vitro. During water deprivation, JNK-2 increased in the supraoptic nucleus but not in the cortex. Osmotic or glutamate receptor stimulation in vitro also resulted in an increase in JNK-2 that was tetrodotoxin (TTX) insensitive and paralleled by increased nuclear phospho-c-Jun immunoreactivity. A TTX-sensitive increase in JNK-3 was seen in smaller neurons. Thus different JNK pathways may mediate individual cellular responses to osmotic stress, with JNK-2 linked to osmotic and glutamate receptor stimulation in magnocellular neuroendocrine cells.
Meeker
R
R
Department of Neurology, University of North Carolina, Chapel Hill, 27599, USA. rbmeeker@med.unc.edu
Fernandes
A
A
D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D002352:Carrier Proteins / Q000096:biosynthesis / Q000235:genetics; D048429:Cell Size / Q000502:physiology; D002478:Cells, Cultured; D007031:Hypothalamus / Q000166:cytology / Q000378:metabolism; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000096:biosynthesis / Q000235:genetics; D048031:JNK Mitogen-Activated Protein Kinases; D048057:Mitogen-Activated Protein Kinase 10; D048056:Mitogen-Activated Protein Kinase 9; D020928:Mitogen-Activated Protein Kinases / Q000096:biosynthesis / Q000235:genetics*; D009474:Neurons / Q000201:enzymology / Q000648:ultrastructure; D009490:Neurosecretory Systems / Q000166:cytology* / Q000201:enzymology*; D009994:Osmolar Concentration; D011505:Protein-Tyrosine Kinases / Q000096:biosynthesis / Q000235:genetics; D051381:Rats; D020318:Rats, Long-Evans; D017470:Receptors, Glutamate / Q000502:physiology*; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism / Q000648:ultrastructure; D013495:Supraoptic Nucleus / Q000166:cytology / Q000378:metabolism; D013779:Tetrodotoxin / Q000494:pharmacology
D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; D007527:Isoenzymes; C408376:MAPK8IP2 protein, human; D017470:Receptors, Glutamate; D016194:Receptors, N-Methyl-D-Aspartate; D013779:Tetrodotoxin; D048057:Mitogen-Activated Protein Kinase 10; D048056:Mitogen-Activated Protein Kinase 9; D011505:Protein-Tyrosine Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases