Definition : A nucleotide is a chemical compound made
up of three parts: a heterocyclic base, a sugar, and one or more phosphate
groups. In the most common nucleotides the base is a derivative of purine or
pyrimidine, and the sugar is pentose - deoxyribose or ribose.
Nucleotides serve as building blocks for making DNA.
Structure of Nucleotides
Nucleotides are the structural units of RNA, DNA, and several cofactors - CoA, FAD, FMN, NADH, and NADP.
Function of Nucleotides
In every cell of the body, they are involved in energy production, metabolism, and signaling.
Nucleotides, available over the counter as "health food" supplements, are biologically active and reduce gastric injury. These compounds could provide a novel inexpensive approach for the prevention and treatment of the injurious effects of non-steroidal anti-inflammatory drugs and other ulcerative conditions of the bowel. Nucleotides are marketed in either pure or mixed forms to promote general health. However, data on the true biologic activity of orally administered nucleotides is limited. In lab-dish experiments with human and rat tissue, researchers have found that the addition of nucleotides leads to an approximately twofold increase in cell migration, a known biological repair response. In rats with induced gastric injury, oral administration of a mixture of nucleotides significantly reduced the degree of injury. Gut, February 2006.
J Nutrition. 2016. Aged Garlic Extract Inhibits Human Platelet Aggregation by Altering Intracellular Signaling and Platelet Shape Change. Increased platelet aggregation plays a pivotal role in the etiology of cardiovascular disease. Upon platelet aggregation, an increase in free cytoplasmic Ca2+ results in the inhibition of soluble guanylyl cyclase (sGC) and adenylyl cyclase (AC), leading to a decrease in cyclic guaninosine-5'-monophosphate (cGMP) and cAMP, respectively. This leads to the activation of the glycoprotein IIb/IIIa (GPIIb/IIIa) fibrinogen receptor, resulting in platelet shape change. Aged garlic extract (AGE) decreases platelet aggregation; however, the mechanisms involved are not clearly defined. Results indicate that AGE inhibits platelet aggregation by increasing cyclic nucleotides and inhibiting fibrinogen binding and platelet shape change.
Single nucleotide polymorphism
The significance of DNA nucleotide variations among individuals, including single nucleotide polymorphisms (SNPs) and/or genome nucleotide mutations as well as to their detection by using new technology, will improve and facilitate the knowledge of each gene sequence. Various tests are being evaluated to determine DNA nucleotide variations.
Front Plant Sci. 2013. Current status and proposed
roles for nitric oxide as a key mediator of the effects of extracellular
nucleotides on plant growth. Recent data indicate that nucleotides are released
into the extracellular matrix during plant cell growth, and that these
extracellular nucleotides induce signaling changes that can, in a dose-dependent
manner, increase or decrease the cell growth. After activation of a presumed
receptor, the earliest signaling change induced by extracellular nucleotides is
an increase in the concentration of cytosolic Ca2+, but rapidly following this
change is an increase in the cellular level of nitric oxide (NO). In
Arabidopsis, mutants deficient in nitrate reductase activity (nia1nia2) have
drastically reduced nitric oxide production and cannot transduce the effects of
applied nucleotides into growth changes. Both increased levels of extracellular
nucleotides and increased NO production inhibit auxin transport and inhibit
growth, and these effects are potentially due to disruption of the localization
and/or function of auxin transport facilitators. However, because NO- and auxin-induced
signaling pathways can intersect at multiple points, there may be diverse ways
by which the induction of NO by extracellular ATP could modulate auxin signaling
and thus influence growth. This review will discuss these optional mechanisms
and suggest possible regulatory routes based on current experimental data and
predictive computational analyses.