[Cloning and analysis of coding cDNA sequence of human lymphocyte Csk tyrosine kinase under normal conditions and in choroidal melanoma].

The main function of Csk tyrosine kinases is phosphorylation of the C-terminal part of Srk tyrosine kinases as a mechanism of their downregulation. A decrease in the expression of csk gene results in the enhancement of Srk tyrosine kinase activity. In this study, cDNA containing the full coding sequence of the human leukocyte Csk tyrosine kinase gene has been cloned.

[Obtaining a full-length encoding cDNA of Csk family tyrosine kinase from human lymphocytes].

Tyrosine kinases of Csk family play important role in the cell growth regulation and normal cell differentiation and also can participate in the process of cancer genesis as oncoproteins. The main function of these tyrosine kinases is the phosphorylation of the Src family tyrosine kinases at their carboxyl terminus, which is the basis of their activity negative regulation. The disturbance of the csk gene expression leads to the increase of the Src tyrosine kinase activity.

[A role of protein kinase C in signal reactions in outer segments of the bovine retinal rods].

The effect of modulators of protein kinase C activity on Ca2+ translocation in dark-adapted and bleached retinal rod outer segments (ROS) was studied. The activators (1,2-diacyl glycerol and phorbol-12-myristate-13-acetate) and the inhibitor (chelerythrine chloride) of protein kinase C were shown to stimulate and inhibit the ATP-dependent Ca(2+)-uptake in dark-adapted retinal ROS, correspondingly. Apparently, this action is due to the influence of protein kinase C on Ca(2+)-ATPase activity in these vesicular structures.

[Role of secondary phosphoinositide messengers in storage of Ca2+ ions in retinal rod microsomes].

The influence of guanosine-5'-triphosphate and secondary messengers forming in rod outer segment membranes during light-stimulated hydrolysis of phosphoinositides on the ATP-dependent Ca(2+)-uptake in microsomes of the retinal rod inner segment was studied. The water-soluble cytoplasmic components of the retinal rod outer segment were shown to be capable of stimulating the Ca(2+)-pump of endoplasmic reticulum after light illumination. This process is likely to proceed with the participation of 1,2-diacylglycerol localized in microsome membrane.

[The calcium-mobilizing effect of inositol-1,4,5-triphosphate in rod outer segments and disks].

The effect of inositol-1,4,5-trisphosphate (IP3) on the release of calcium ions from retinal rod discs was studied. It was shown that the release of Ca2+ from discs is an electroneutral process. The intradiscal calcium concentration during the release of the ion from the organelle decreases by 1 mM.