The behaviour of cells is coordinated by a large array of different types of intracellular protein kinases, protein phosphatases and second messenger molecules. Current experimental evidence suggests that these kinases, phosphatases and other messengers form a vast complicated interconnected signalling network inside the cell. A generic model of this signalling network is presented which is spe...

Translational regulation at the molecular level has been studied intensively with components from mammalian reticulocytes. Since the discovery of translational control by phosphorylation-dephosphorylation of initiation factor eIF-2 [1-3] and possibly 40 S ribosomal subunits [4-7], relevant protein kinases and recently counteracting phosphatases have become targets of research. The extent of pho...

Specific inhibition of types 1 and 2A protein phosphatases by microinjection of okadaic acid (OA) into starfish oocytes induced germinal vesicle breakdown and activation of M phase-promoting factor (MPF) and histone H1 kinase. The effects were evident in immature oocytes arrested at first meiotic prophase as well as in fully mature oocytes arrested at the pronucleus stage. In addition, MPF and ...

(magenta) which are mainly found on loops between The phosphate ester is an extremely important chemical secondary structural elements of the b-a-b-a-b motif. bond within the living cell, serving as an energy source, These loops also contain important catalytic residues as a means of joining RNA/DNA molecules, and as an (proposed residues are highlighted in color, Figure 1). efficient mechanism...

The effect of theta pulse stimulation (TPS) on pentylenetetrazol (PTZ)-induced long-term potentiation of population spikes (PS) was studied in the hippocampal CA1 in vitro. A transient PTZ application produced a long-lasting enhancement of PS amplitude. A 3-min episode of TPS delivered at a higher intensity produced complete reversal of the PTZ potentiation when delivered during the last minute...

to determine the extent and the size of the environment pollution with heavy metals, biologicalmethods, investigating the enzymatic activity of soil can be applied. most frequently, the enzymes investigated in the soils threatened with anthropogenic contamination are phosphatases, dehydrogenases as reacting fastest to the increase in the content of heavy metals in the environment. the aim of th...

Many oncogenes encode proteins with a tyrosine kinase activity that appears to be directly involved in the process of transformation. Because these kinases are themselves activated for transformation by tyrosine phosphorylation, proteins which remove phosphate from tyrosine residues, protein tyrosine phosphatases (also termed phosphotyrosine phosphatases and protein phosphotyrosyl phosphatases)...

Protein phosphatases regulated by calmodulin (CaM) mediate the action of intracellular Ca2+ and modulate functions of various target proteins by dephosphorylation. In plants, however, the role of Ca2+ in the regulation of protein dephosphorylation is not well understood due to a lack of information on characteristics of CaM-regulated protein phosphatases. Screening of a cDNA library of the moss...