Roscovitine and purvalanol are purine derivative cyclin-dependent kinase (CDK) inhibitors that induce apoptosis in various types of cancer cells. However, their impact on the apoptotic cell death mechanism requires further elucidation. Natural polyamines putrescine, spermidine and spermine play essential roles in the regulation of cell growth and proliferation. Increased levels of polyamines in...

Vibrio cholerae is the causative agent of the severe enteric disease cholera. To cause cholera the bacterium must be able to synthesize both cholera toxin (CT) and toxin-coregulated pilus (TCP) which mediates autoagglutination and is required for colonization of the small intestine. Only a few environmental signals have been shown to regulate V. cholerae virulence gene expression. Polyamines, w...

Putrescine (diaminobutane) was previously found to stimulate proliferation of human fibroblasts in tissue culture, and a growth factor produced by these cells was identified as putrescine. In the present paper putrescine transport is studied. The rate of putrescine transport was dependent on temperature, and most of the labeled putrescine was retained by the cells after washing with excess unla...

The total cellular mass of the small intestine is well controlled and can adapt, with hypo- or hyperplasia, to a wide variety of stimuli. Luminal nutrients, hormonal factors and pancreatic and biliary secretions have all been implicated in the regulation of intestinal mucosal growth. The polyamines (putrescine, spermidine and spermine) and the key enzyme controlling their synthesis (ornithine d...

Polyamines are plant growth regulators distributed among all plant species. The major polyamines are diamine putrescine, triamine spermidine and tetraamine spermine. Polyamines are involved in a number of growth and developmental processes, as well as in plant responses to a variety of unfavorable factors. Polyamines can stabilize cell constituents and protect macromolecules from free radicals ...

Blocks of potential Z-DNA-forming (dA-dC)n.(dG-dT)n sequences are ubiquitous in eukaryotic genomes. We examined whether naturally occurring polyamines, putrescine, spermidine and spermine, could provoke the Z-DNA conformation in plasmids pDHf2 and pDHf14 with 23 and 60 bp inserts respectively of (dA-dC)n.(dG-dT)n sequences using an e.l.i.s.a. Spermidine and spermine could provoke Z-DNA conforma...

The cellular polyamines putrescine, spermidine, and spermine accelerate the aggregation and fibrillization of -synuclein, the major protein component of Lewy bodies associated with Parkinson’s disease. Circular dichroism and fluorometric thioflavin T kinetic studies showed a transition of -synuclein from unaggregated to highly aggregated states, characterized by lag and transition phases. In th...

Transformed baby-hamster-kidney cells contain higher intracellular concentrations of polyamines than do normal cells. The difference is greater in high-density confluent cultures. Transformed cells incorporate exogenous putrescine into the cells at a faster rate than do normal cells. They also show a marked increase in the rate of spermine biosynthesis compared with normal cells. Transformed ce...

Many effects of polyamines (PAs) are well known in plant developmental processes; however, the significance their catabolism is not understood. Copper amine oxidase (CuAO) involved degradation diamine putrescine (Put). The genotype dependence and time-dependent this enzyme rarely examined, so study aims to discover role CuAO tomato genotypes different stages seedling development. Exogenously ap...