Transport and golgi organization 2 homolog (TANGO2) also known as chromosome 22 open reading frame 25 (C22orf25) is a
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...
that in humans is encoded by the TANGO2 gene.
The function of C22orf25 is not currently known. It is characterized by the NRDE superfamily domain (DUF883), which is strictly known for the conserved
amino acid
Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha am ...
sequence of (N)-
Asparagine
Asparagine (symbol Asn or N) is an α-amino acid that is used in the biosynthesis of proteins. It contains an α-amino group (which is in the protonated −NH form under biological conditions), an α-carboxylic acid group (which is in the depro ...
(R)-
Arginine
Arginine is the amino acid with the formula (H2N)(HN)CN(H)(CH2)3CH(NH2)CO2H. The molecule features a guanidino group appended to a standard amino acid framework. At physiological pH, the carboxylic acid is deprotonated (−CO2−) and both the am ...
(D)-
Aspartic Acid
Aspartic acid (symbol Asp or D; the ionic form is known as aspartate), is an α-amino acid that is used in the biosynthesis of proteins. Like all other amino acids, it contains an amino group and a carboxylic acid. Its α-amino group is in the pro ...
(E)-
Glutamic Acid
Glutamic acid (symbol Glu or E; the ionic form is known as glutamate) is an α-amino acid that is used by almost all living beings in the biosynthesis of proteins. It is a non-essential nutrient for humans, meaning that the human body can synt ...
. This domain is found among distantly related
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
from the six kingdoms:
Eubacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of prokaryotic microorganisms. Typically a few micrometr ...
,
Archaebacteria,
Protista
A protist () is any eukaryotic organism (that is, an organism whose cells contain a cell nucleus) that is not an animal, plant, or fungus. While it is likely that protists share a common ancestor (the last eukaryotic common ancestor), the excl ...
,
Fungi
A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from ...
,
Plantae
Plants are predominantly Photosynthesis, photosynthetic eukaryotes of the Kingdom (biology), kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all curr ...
, and
Animalia
Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, and go through an ontogenetic stage in ...
and is known to be involved in
Golgi organization and protein secretion. It is likely that it localizes in the
cytoplasm
In cell biology, the cytoplasm is all of the material within a eukaryotic cell, enclosed by the cell membrane, except for the cell nucleus. The material inside the nucleus and contained within the nuclear membrane is termed the nucleoplasm. The ...
but is anchored in the
cell membrane
The cell membrane (also known as the plasma membrane (PM) or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of all cells from the outside environment ( ...
by the second amino acid.
C22orf25 is also
xenolog
Sequence homology is the homology (biology), biological homology between DNA sequence, DNA, RNA sequence, RNA, or Protein primary structure, protein sequences, defined in terms of shared ancestry in the evolutionary history of life. Two segments ...
ous to T10 like proteins in the
Fowlpox Virus
Fowlpox is the worldwide disease of poultry caused by viruses of the family ''Poxviridae'' and the genus ''Avipoxvirus''. The viruses causing fowlpox are distinct from one another but antigenically similar, possible hosts including chickens, tur ...
and
Canarypox Virus
Canarypox virus (CNPV) is an ''Avipoxvirus'' and etiologic agent of canarypox, a disease of wild and captive birds that can cause significant losses. Canarypox can enter human cells, but it cannot survive and multiply in human cells. There is a ...
. The gene coding for C22orf25 is located on
chromosome 22
Chromosome 22 is one of the 23 pairs of chromosomes in human cell (biology), cells. Humans normally have two copies of chromosome 22 in each cell. Chromosome 22 is the second smallest human chromosome, spanning about 49 million DNA base pairs and ...
and the location q11.21, so it is often associated with
22q11.2 deletion syndrome
DiGeorge syndrome, also known as 22q11.2 deletion syndrome, is a syndrome caused by a microdeletion on the long arm of chromosome 22. While the symptoms can vary, they often include congenital heart problems, specific facial features, frequent i ...
.
Protein
Gene neighborhood
The C22orf25 gene is located on the long arm (q) of chromosome 22 in region 1, band 1, and sub-band 2 (22q11.21) starting at 20,008,631
base pairs
A base pair (bp) is a fundamental unit of double-stranded nucleic acids consisting of two nucleobases bound to each other by hydrogen bonds. They form the building blocks of the DNA double helix and contribute to the folded structure of both DNA ...
and ending at 20,053,447 base pairs.
There is a 1.5-3.0 Mb deletion containing around 30-40
genes
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...
, spanning this region that causes the most survivable genetic deletion disorder known as
22q11.2 deletion syndrome
DiGeorge syndrome, also known as 22q11.2 deletion syndrome, is a syndrome caused by a microdeletion on the long arm of chromosome 22. While the symptoms can vary, they often include congenital heart problems, specific facial features, frequent i ...
, which is most commonly known as DiGeorge syndrome or Velocaridofacial syndrome. 22q11.2 deletion syndrome has a vast array of
phenotypes
In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology or physical form and structure, its developmental processes, its biochemical and physiological proper ...
and is not attributed to the loss of a single gene. The vast phenotypes arise from deletions of not only DiGeorge Syndrome Critical Region (DGCR) genes and disease genes but other unidentified genes as well.
C22orf25 is in close proximity to DGCR8 as well as other genes known to play a part in DiGeorge Syndrome such as armadillo repeat gene deleted in Velocardiofacial syndrome (
ARVCF), Cathechol-O-methyltransferase (
COMT) and T-box 1 (
TBX1
T-box transcription factor TBX1 also known as T-box protein 1 and testis-specific T-box protein is a protein that in humans is encoded by the TBX1 gene. Genes in the T-box family are transcription factors that play important roles in the formation ...
).
Predicted mRNA features
Promoter
The
promoter for the C22orf25 gene spans 687 base pairs from 20,008,092 to 20,008,878 with a predicted
transcriptional start site that is 104 base pairs and spans from 20,008,591 to 20,008,694. The promoter region and beginning of the C22orf25 gene (20,008,263 to 20,009,250) is not conserved past primates. This region was used to determine
transcription factor
In molecular biology, a transcription factor (TF) (or sequence-specific DNA-binding factor) is a protein that controls the rate of transcription of genetic information from DNA to messenger RNA, by binding to a specific DNA sequence. The fu ...
interactions.
Transcription factors
Some of the main transcription factors that bind to the promoter are listed below.
Expression analysis
Expression data from
Expressed Sequence Tag mapping,
microarray
A microarray is a multiplex lab-on-a-chip. Its purpose is to simultaneously detect the expression of thousands of genes from a sample (e.g. from a tissue). It is a two-dimensional array on a solid substrate—usually a glass slide or silicon t ...
and
''in situ'' hybridization show high expression for ''Homo sapiens'' in the
blood
Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in the c ...
,
bone marrow
Bone marrow is a semi-solid tissue found within the spongy (also known as cancellous) portions of bones. In birds and mammals, bone marrow is the primary site of new blood cell production (or haematopoiesis). It is composed of hematopoietic ce ...
and
nerves. Expression is not restricted to these areas and low expression is seen elsewhere in the body. In ''
Caenorhabditis elegans
''Caenorhabditis elegans'' () is a free-living transparent nematode about 1 mm in length that lives in temperate soil environments. It is the type species of its genus. The name is a blend of the Greek ''caeno-'' (recent), ''rhabditis'' (ro ...
'', the snt-1 gene (C22orf25 homologue) was expressed in the nerve ring, ventral and dorsal cord processes, sites of neuromuscular junctions, and in neurons.
Evolutionary history
The NRDE (DUF883) domain, is a domain of unknown function spanning majority of the C22orf25 gene and is found among distantly related species, including viruses.
Predicted protein features
Post translational modifications
Post translational modifications of the C22orf25 gene that are evolutionarily conserved in the Animalia and Plantae kingdoms as well as the Canarypox Virus include
glycosylation
Glycosylation is the reaction in which a carbohydrate (or ' glycan'), i.e. a glycosyl donor, is attached to a hydroxyl or other functional group of another molecule (a glycosyl acceptor) in order to form a glycoconjugate. In biology (but not al ...
(C-mannosylation),
glycation
Glycation (sometimes called non-enzymatic glycosylation) is the covalent attachment of a sugar to a protein or lipid. Typical sugars that participate in glycation are glucose, fructose, and their derivatives. Glycation is the non-enzymatic proces ...
,
phosphorylation
In chemistry, phosphorylation is the attachment of a phosphate group to a molecule or an ion. This process and its inverse, dephosphorylation, are common in biology and could be driven by natural selection. Text was copied from this source, wh ...
(kinase specific), and
palmitoylation
Palmitoylation is the covalent attachment of fatty acids, such as palmitic acid, to cysteine (''S''-palmitoylation) and less frequently to serine and threonine (''O''-palmitoylation) residues of proteins, which are typically lipid bilayer, memb ...
.
Predicted topology
C22orf25 localizes to the cytoplasm and is anchored to the cell membrane by the second amino acid. As mentioned previously, the second amino acid is modified by palmitoylation. Palmitoylation is known to contribute to membrane association because it contributes to enhanced hydrophobicity.
Palmitoylation is known to play a role in the modulation of proteins' trafficking, stability and sorting. Palmitoylation is also involved in cellular signaling
and neuronal transmission.
Protein Interactions
C22orf25 has been shown to interact with
NFKB1,
RELA
Transcription factor p65 also known as nuclear factor NF-kappa-B p65 subunit is a protein that in humans is encoded by the ''RELA'' gene.
RELA, also known as p65, is a REL-associated protein involved in NF-κB heterodimer formation, nuclear tran ...
,
RELB
Transcription factor RelB is a protein that in humans is encoded by the ''RELB'' gene.
Interactions
RELB has been shown to interact with NFKB2, NFKB1, and C22orf25.
Activation and function
In resting cells, RelB is sequestered by the NF-κ ...
,
BTRC,
RPS27A
40S ribosomal protein S27a is a protein that in humans is encoded by the ''RPS27A'' gene.
Ubiquitin, a highly conserved protein that has a major role in targeting cellular proteins for degradation by the 26S proteosome, is synthesized as a precurs ...
,
BCL3
B-cell lymphoma 3-encoded protein is a protein that in humans is encoded by the ''BCL3'' gene.
This gene is a proto-oncogene candidate. It is identified by its translocation into the immunoglobulin alpha-locus in some cases of B-cell leukemia. T ...
,
MAP3K8
Mitogen-activated protein kinase kinase kinase 8 is an enzyme that in humans is encoded by the ''MAP3K8'' gene.
Function
The gene was identified by its oncogenic transforming activity in cells. The encoded protein is a member of the serine/thr ...
,
NFKBIA,
SIN3A
Paired amphipathic helix protein Sin3a is a protein that in humans is encoded by the ''SIN3A'' gene.
Function
The protein encoded by this gene is a transcriptional regulatory protein. It contains paired amphipathic helix (PAH) domains, which a ...
,
SUMO1
Small ubiquitin-related modifier 1 is a protein that in humans is encoded by the ''SUMO1'' gene.
Function
This gene encodes a protein that is a member of the SUMO (small ubiquitin-like modifier) protein family. It is a ubiquitin-like protein an ...
,
Tat.
Clinical significance
Mutations in the TANGO2 gene may cause defects in mitochondrial
β-oxidation
In biochemistry and metabolism, beta-oxidation is the catabolic process by which fatty acid molecules are broken down in the cytosol in prokaryotes and in the mitochondria in eukaryotes to generate acetyl-CoA, which enters the citric acid cycle, ...
and increased
endoplasmic reticulum
The endoplasmic reticulum (ER) is, in essence, the transportation system of the eukaryotic cell, and has many other important functions such as protein folding. It is a type of organelle made up of two subunits – rough endoplasmic reticulum ( ...
stress and a reduction in
Golgi volume density.
These mutations results in early onset
hypoglycemia
Hypoglycemia, also called low blood sugar, is a fall in blood sugar to levels below normal, typically below 70 mg/dL (3.9 mmol/L). Whipple's triad is used to properly identify hypoglycemic episodes. It is defined as blood glucose belo ...
,
hyperammonemia
Hyperammonemia is a metabolic disturbance characterised by an excess of ammonia in the blood. It is a dangerous condition that may lead to brain injury and death. It may be primary or secondary.
Ammonia is a substance that contains nitrogen. It i ...
,
rhabdomyolysis
Rhabdomyolysis (also called rhabdo) is a condition in which damaged skeletal muscle breaks down rapidly. Symptoms may include muscle pains, weakness, vomiting, and confusion. There may be tea-colored urine or an irregular heartbeat. Some of th ...
,
cardiac arrhythmia
Arrhythmias, also known as cardiac arrhythmias, heart arrhythmias, or dysrhythmias, are irregularities in the heartbeat, including when it is too fast or too slow. A resting heart rate that is too fast – above 100 beats per minute in adults ...
s, and
encephalopathy that later develops into cognitive impairment.
References
{{Reflist, 33em
External links
www.tango2.it - Disease website
www.tango2research.org - Research disease website -