Various stressors rapidly activate the p38-MAPK signaling pathway in Mytilus galloprovincialis (Lam.).
The stimulation of p38-MAPK signal transduction pathway by various stressful stimuli was investigated in the marine bivalve M. galloprovincialis. Oxidative stress (5 microM H2O2) induced a biphasic pattern of p38-MAPK phosphorylation with maximal values attained at 15 min (8.1-fold) and 1 h (8.0-fold) of treatment respectively. Furthermore, 1 microM SB203580 abolished the p38-MAPK phosphorylation induced by oxidative stress. Aerial exposure also induced a biphasic pattern of p38-MAPK phosphorylation, with maximal values attained at 1 h (6.8-fold) and 8 h (4.9-fold) respectively. Re-oxygenation following a 15 min of aerial exposure resulted in the progressive dephosphorylation of the kinase. Treatment with 0.5 M sorbitol (in normal seawater) induced the rapid kinase phosphorylation (9.2-fold) and this effect was reversible. Seawater salinities varying between 100-60% had no effect, whereas a salinity of 50% induced a significant p38-MAPK phosphorylation. Furthermore, hypertonicity (120% seawater) resulted in a moderate kinase phosphorylation. All the above results demonstrate for the first time in a marine invertebrate imposed to environmental and other forms of stress as an intact, living organism, that the p38-MAPK pathway is specifically activated by various stressful stimuli which this animal can often face and sustain in vivo.
Gaitanaki
Catherine
C
Department of Animal and Human Physiology, School of Biology, Faculty of Sciences, University of Athens, Panepistimioupolis, Athens, Greece.
Kefaloyianni
Erene
E
Marmari
Athina
A
Beis
Isidoros
I
D000818:Animals; D049872:Bivalvia / Q000187:drug effects* / Q000378:metabolism; D015153:Blotting, Western; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D007038:Hypotonic Solutions; D007093:Imidazoles / Q000494:pharmacology; D020935:MAP Kinase Signaling System / Q000187:drug effects; D008297:Male; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D016877:Oxidants / Q000494:pharmacology; D010766:Phosphorylation / Q000187:drug effects; D011725:Pyridines / Q000494:pharmacology; D012965:Sodium Chloride / Q000494:pharmacology; D013012:Sorbitol / Q000494:pharmacology; D013997:Time Factors; D048051:p38 Mitogen-Activated Protein Kinases
D004791:Enzyme Inhibitors; D007038:Hypotonic Solutions; D007093:Imidazoles; D016877:Oxidants; D011725:Pyridines; D012965:Sodium Chloride; D013012:Sorbitol; D006861:Hydrogen Peroxide; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; C093642:SB 203580