Development of eggs after a blood meal in the yellow fever mosquito Aedes aegypti involves hormonal changes, synthesis of nucleic acids, activation of the digestive enzyme trypsin, and production of the yolk protein vitellogenin. Polyamines have been implicated in growth processes and were here examined for possible involvement during egg development. The data suggest that polyamines are import...

Plants are challenged by a variety of biotic or abiotic stresses, which can affect their growth and development, productivity, and geographic distribution. In order to survive adverse environmental conditions, plants have evolved various adaptive strategies, among which is the accumulation of metabolites that play protective roles. A well-established example of the metabolites that are involved...

In this study, we investigated the hypothesis that inhibition of the N-methyl-D-aspartate (NMDA) receptor complex by zinc involves a polyamine-sensitive regulatory site. We found that the specific binding of the open channel ligand [3H]MK-801 to rat hippocampal membranes 1) was inhibited by low concentrations of Zn2+ (IC50 = 5.5 microM) by 65%. 2) This high-affinity component of inhibition was ...

Mammalian polyamine catabolism is under the control of two enzymes, spermidine/spermine N1-acetyltransferase and the flavin adenine dinucleotide-dependent polyamine oxidase (PAO). In this study, the cloning and initial characterization of human PAO is reported. A 1894-bp cDNA with an open reading frame of 1668-bp codes for a protein of 555 amino acids. In vitro transcription/translation of this...

Feedback inhibition is a common mechanism to adjust the activity of an enzyme in accordance with the abundance of a product. The enzyme catalyzing the initial, committing step of a biosynthesis cascade is subject to negative feedback by the end-product. This kind of regulation is frequent in all cell types to regulate biosynthesis of numerous metabolites; a classical textbook example is the ser...

The relationship between hydrogen peroxide and polyamine metabolism the role of NADPH oxidase (NOX) in this under drought conditions has not yet been clarified. To reveal relationship, expression levels genes metabolism, such as arginine decarboxylase (ADC), agmatine aminohydrolase (AIH), spermidine synthase (SPDS), S-adenosyl methionine (SAMDC), diamine (DAO) (PAO) were determined by RT PCR st...

The polyamines spermidine and spermine, and their precursor putrescine, are required for cell growth and cellular functions. The high levels of tissue polyamines are implicated in carcinogenesis. The major sources of exogenous polyamines are diet and intestinal luminal bacteria in gastrointestinal (GI) tissues. Both endocytic and solute carrier-dependent mechanisms have been described for polya...

Intestinal epithelium is a rapidly self-renewing tissue in the body, and its homeostasis is tightly regulated by numerous factors including polyamines. Decreased levels of cellular polyamines increase activating transcription factor (ATF)-2, but the exact role and mechanism of induced ATF-2 in the regulation of intestinal epithelial cell (IEC) growth remain elusive. Cyclin-dependent kinase (CDK...