Dehydrin stress proteins in Pinus sylvestris L. needles under conditions of extreme climate of Yakutia

This is the first study to investigate stress proteins dehydrins with the use of specific antibodies in the Scots pine (Pinus sylvestris L.) needles and their changes in the annual cycle under extreme climate of Yakutia. No pronounced polymorphism of major dehydrins (14-15 and 66 kDa) has been found during the winter dormancy period of P. sylvestris. A clear correlation between the seasonal variations in dehydrins and changes in the water content in needles was revealed. Consistently high levels of dehydrins was retained throughout the period of low negative temperatures. It is assumed that dehydrins can participate in the formation of P. sylvestris L. resistance to the permafrost conditions.

DEHYDRIN- STRESS PROTEINS OF BIRCH BUDS IN CONTRASTING CLIMATIC REGIONS

Stress proteins dehydrins have been identified using specific antibodies in buds silver birch (Betula pendula Roth) growing in contrasting climatic conditions of the regions Karelia and Central Yakutia. Dehydrins in buds of plants are presented in two areas: medium molecular weight (56-73 kDa) and low molecular weight (14-21 kDa), and 17 kDa dehydrin was detected in all studied birches. 14-21 kDa dehydrins are the most susceptible to seasonal changes. Regardless of birch growing region, dehydrines 14-21 kDa show significant increase in their level in the autumn and winter when the trees are characterized by the highest frost resistances. Dehydrins have relealed intraspecific polymorphism, more pronounced in Yakutia plants in conditions of extreme continental climate, compared with Karelia, which is probably due to the peculiarities of woody plants to adapt to the extremely low winter temperature of the permafrost zone.

How sesquiterpenes modulate signaling cascades in cancers

Data obtained from high-throughput technologies has started to shed light on the interplay between signal transduction cascades and chromatin modifications thus adding another layer of complexity to the already complex regulation of the protein network. Based on the insights gleaned from almost a decade of research, it has now been convincingly revealed that sesquiterpenes effectively modulated different intracellular signaling cascades in different cancers. In this review we summarize how sesquiterpenes mediated Wnt, Shh, Notch and TRAIL induced signaling cascades.

[Radioecological situation in the impact zone of the accidental underground nuclear explosion "Kraton-3" in the Republic of Sakha (Yakutia)]

The paper reports on the results of a ground walking gamma- and gamma-spectrometric survey made in the impact zone of the accidental underground nuclear explosion "Kraton-3". Patterns of migration, 137Cs, 90Sr and Pu distribution in the soil-vegetable cover of the northern taiga on permafrost are considered. Radioeco- logical situation within the territory surveyed is noted as unfavorable.

[Kinetics of sodium current inactivation in Ranvier's node membrane]

The possibility to describe the inactivation kinetics of sodium current in the Ranvier node membrane in terms of models with independent processes of activation and inactivation, was experimentally tested. Dependence of kinetic characteristics on the potential suggested the existence of three types of nerve fibers with different models of inactivation system. The models with independent systems of activation and inactivation were concluded to be not quite adequate.

[Kinetic model of the gating system of the sodium channel in a Ranvier node membrane]

A kinetic model of the sodium channel gating system consisting of four subunits with three states--closed (X), open (Y) and inactivated (Z)--is proposed. For the channel to conduct, all the four subunits must be in the open state. The transitions between states X and Y are independent, while those between states X and Z are coupled, so that for the particle considered transition of one of two neighbouring particles into state Z increases the activation energy of the step by kT. The model fits rather well to the experimental data.