Antizyme RNA frameshifting stimulation element is a
structural element which is found in
antizyme mRNA and is known to promote
frameshifting. Antizyme genes have two partially overlapping
open reading frame
In molecular biology, open reading frames (ORFs) are defined as spans of DNA sequence between the start and stop codons. Usually, this is considered within a studied region of a Prokaryote, prokaryotic DNA sequence, where only one of the #Six-fra ...
s, the second, which encodes the functional (antizyme) protein requires +1 translational frameshifting. This frameshift is stimulated by a
pseudoknot present 3' of the frameshift site in the antizyme mRNA. The frameshifting efficiency is dependent on the concentration of
polyamine
A polyamine is an organic compound having more than two amino groups. Alkyl polyamines occur naturally, but some are synthetic. Alkylpolyamines are colorless, hygroscopic, and water soluble. Near neutral pH, they exist as the ammonium derivatives. ...
s in the cell, when the polyamine concentration is high frameshifting is more likely to occur which leads to an increase in the quantity of functional antizyme produced. The functional antizyme acts to reduce
ornithine decarboxylase
The enzyme ornithine decarboxylase (, ODC) catalyzes the decarboxylation of ornithine (a product of the urea cycle) to form putrescine. This reaction is the committed step in polyamine synthesis. In humans, this protein has 461 amino acids and for ...
(ODC) activity which leads to a drop in polyamines present in the cell. Therefore, this family can be thought of as a
biosensor
A biosensor is an analytical device, used for the detection of a chemical substance, that combines a biological component with a physical chemistry, physicochemical detector.
The ''sensitive biological element'', e.g. tissue, microorganisms, or ...
for intracellular free polyamines that functions via a negative feedback loop.
References
External links
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Cis-regulatory RNA elements
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