Kurchii, B.A. .
A kinase signaling cascade: rambling in the labyrinth?.
There are considerable similarities between mammals and plants in the functioning of the signaling pathways, especially in the area of nitric oxide (NO) and ethylene (ET) signaling cascades. There are mounting reports designing positive or negative effects on living systems of these substances, and there are nothing strong data confirming their formation through gene activation as the starting mechanism of formation and action of physical or chemical factors. The next questions remain to be answered: “Formation of ET and NO in plants and animals is cause or consequence of oxidative stress action?“ And why researchers ignore an excellent work of Burg and Burg (1972) showing the lost of biological activity of olefins with the increasing of carbon chain up to about 8 carbons? Why so different in the sizes chemicals as very small ET or NO and very large cyclic peptides possess in similar effects: stimulation of growth in the low, inhibition in moderate, and lethal effects in high concentrations? We believe that kinase (MAPK AND MAPKK) signaling cascade (pathways) is rambling in the labyrinth. Our viewpoint is that these substances are formed as a result from the oxidative breakdown of cellular substances and structures. At the same time ET and NO having unsaturated functional groups are activated in vivo in the free radical addition reactions of endogenous metabolic free radical to these bonds. Formed free radical of ET and NO initiate free radical chain reactions (unregulated by endogenous antioxidants), first of all in the membraneous lipids, i.e. they act as secondary oxidative agent (autocatalysis) in the tissues. Nevertheless, in the living system signaling molecules can be presented by gene codes (double strands of RNA or DNA) that are synthesized preliminary, safeguard and stored during normal physiological state, and are liberated to initiate transcription during oxidative stress.
1 - Institute of Plant Physiology and Genetics, 31/17 Vasylkivska St., Kiev, , Ukraine
nitric oxide and ethylene signaling cascades
free radical chain reactions
Presentation Type: Poster
Location: Special Event Center (Cliff Lodge)
Date: Tuesday, August 3rd, 2004
Time: 12:30 PM