The NF-kB-dependent signaling pathways are essential components of cellular response to stress. Mammalian family of NF-kB consists of five NF-kB/Rel proteins, which are subunits of the NF-kB transcription factor, and four IkB proteins, which are their specific inhibitors. Activation of NF-kB requires degradation of IkB, which allows nuclear translocation of NF-kB and its binding to cisacting DNA regulatory elements. NF-kB transcription factors regulate expression of numerous genes, which are involved in cell proliferation, apoptosis, immune response and inflammatory response.

A development of contemporary methods of therapy as gene therapy is directly based on a search of genes that encode therapeutic proteins. Angiogenic gene therapy takes advantage of genes encoding proangio- genic factors. It is described that embryonic sonic hedgehog protein is a strong stimulator of neovascularization. Sonic hedgehog is implicated in the regulation of central nervous system polarity and differentiation of various organs.

Changes of sugar concentration often affect germination, plant growth, metabolic processes and the expression of numerous genes. Plants developed effective mechanisms of perception and trans- duction of sugar signals. Glucose, sucrose, trehalose and other sugars might serve as elicitors of plant sugar signaling. Hexokinase, sucrose and glucose transporters (and specific sugar receptors) have been proposed as components of sugar sensing machinery. Roles of G-proteins and specific serine/threonine kinases and phosphatases in sugar signal transduction in plant cell are discussed.

VEGF-A is a glycoprotein, which belongs to the vascular endothelial growth factor family. The human VEGF-A gene is composed of 8 exons, separated by 7 introns and is localized in chromosome 6p21.3. Alternative exon splicing of a single VEGF gene results in the generation of the ten different isoforms known as 121, 138, 145, 148, 162, 162b, 165, 183, 189 and 206. VEGF-A binds to two tyrosine kinase receptors Flt-1 and Flk-1.

Phytoestrogens are plant-derived chemical compounds which may affect reproductive processes in humans and animals. In their target cells, phytoestrogens may mimic (estrogenic effects) or antagonize (antiestrogenic effects) action of endogenous estrogens. In the current paper, contemporary views are presented on intracellular mechanism of phytoestrogen action in ovarian, uterine, and mammary gland cells.

Cytokines play an important role in defining the fate of cells, such as proliferation, differentiation or death. Distinct responses of target cells to cytokines are determined by specific signal transduction events. The group of interleukin-6-type cytokines comprises also: interleukin-11 (IL-11), oncostatinM (OSM), leukemia inhibitory factor (LIF), ciliary neurotrophic factor (CNTF) and cardiotrophin-I (CT-I). IL-6-type cytokines use pl30 as a common b chain of their multimeric receptor complexes.

Interleukin 1 (IL-1) is one of the major proinflammatory cytokines responsible for the regulation of immune and inflammatory response. In this paper we present up-to date information concerning the mechanisms of intracellular signal transduction induced by this cytokine. Interleukin 1 effects on target cells are mediated via membrane receptors. One of them (type I) is responsible for interleukin 1 intracellular signaling, whereas the other (type II) is a natural regulator of the cytokine activity.