The gamma interferon inhibitor of translation element or GAIT element is a
cis-acting
''Cis''-regulatory elements (CREs) or ''cis''-regulatory modules (CRMs) are regions of non-coding DNA which regulate the transcription of neighboring genes. CREs are vital components of genetic regulatory networks, which in turn control morpho ...
RNA
Ribonucleic acid (RNA) is a polymeric molecule that is essential for most biological functions, either by performing the function itself (non-coding RNA) or by forming a template for the production of proteins (messenger RNA). RNA and deoxyrib ...
element located in the
3'-UTR of the
ceruloplasmin
Ceruloplasmin (or caeruloplasmin) is a ferroxidase enzyme that in humans is encoded by the ''CP'' gene.
Ceruloplasmin is the major copper-carrying protein in the blood, and in addition plays a role in iron metabolism. It was first described in ...
(Cp)
mRNA
In molecular biology, messenger ribonucleic acid (mRNA) is a single-stranded molecule of RNA that corresponds to the genetic sequence of a gene, and is read by a ribosome in the process of Protein biosynthesis, synthesizing a protein.
mRNA is ...
.
The GAIT element forms a
stem-loop
Stem-loops are nucleic acid Biomolecular structure, secondary structural elements which form via intramolecular base pairing in single-stranded DNA or RNA. They are also referred to as hairpins or hairpin loops. A stem-loop occurs when two regi ...
secondary structure. The GAIT element is involved in selective translational silencing of the Cp transcript within monocytic cells, but not hepatic cells. Cp is a multifunctional, copper-containing glycoprotein produced by the liver and secreted into the plasma for its role in copper and iron homeostasis. Ceruloplasmin is also an acute-phase protein produced by monocytes, and its plasma concentration can double during multiple inflammatory conditions through increased Cp production by monocytic cells after stimulation by
interferon gamma
Interferon gamma (IFNG or IFN-γ) is a dimerized soluble cytokine that is the only member of the type II class of interferons. The existence of this interferon, which early in its history was known as immune interferon, was described by E. F. ...
(IFNγ). Plasma Cp has been reported to be an independent risk factor for
cardiovascular disease
Cardiovascular disease (CVD) is any disease involving the heart or blood vessels. CVDs constitute a class of diseases that includes: coronary artery diseases (e.g. angina, heart attack), heart failure, hypertensive heart disease, rheumati ...
, including atherosclerosis, carotid restenosis after endarterectomy, and myocardial infarction. Translational silencing of Cp, and possibly other transcripts, mediated by the GAIT element may contribute to the resolution of the local inflammatory response following cytokine activation of macrophages.
The silencing of Cp protein translation in IFN-gamma-stimulated monocytes is accomplished by binding of the IFN-gamma-activated inhibitor of translation (GAIT) inhibitor complex to the GAIT element.
The GAIT complex consists of the proteins
ribosomal protein L13a,
glutamyl-prolyl-tRNA synthetase,
NS1-associated protein-1, and
glyceraldehyde 3-phosphate dehydrogenase
Glyceraldehyde 3-phosphate dehydrogenase (abbreviated GAPDH) () is an enzyme of about 37kDa that catalyzes the sixth step of glycolysis and thus serves to break down glucose for energy and carbon molecules. In addition to this long establis ...
.
References
External links
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Cis-regulatory RNA elements
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