CARKD
Encyclopedia
Carbohydrate kinase domain containing protein, also known as CARKD, is a human protein
of unknown function. The protein is conserved throughout many species, and has predicted orthologs through eukaryote
s, bacteria
, and archea.
: ribokinase
/ pfkB superfamily. This family is characterized by the presence of a domain
shared by the family. CARKD contains a carbohydrate kinase domain . This family is related to and implying that it also is a carbohydrate kinase.
:
s. Its expression is lower in oligodendrocyte progenitor cells than in mature oligodendrocytes.
) was predicted to be a binding partner for CARKD. This prediction is based on co-occurrence across genomes and co-expression. In addition to these data, the orthologs of CARKD in E. coli
contain a domain similar to APOA1BP. This indicates that the two proteins are likely to have originated from a common evolutionary ancestor and, according to Rosetta stone analysis theory, are likely interaction partners even in species such as humans where the two proteins are not produced as a single polypeptide.
. In addition, microarray
data indicates that CARKD is up-regulated in Glioblastoma multiforme
tumors.
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
of unknown function. The protein is conserved throughout many species, and has predicted orthologs through eukaryote
Eukaryote
A eukaryote is an organism whose cells contain complex structures enclosed within membranes. Eukaryotes may more formally be referred to as the taxon Eukarya or Eukaryota. The defining membrane-bound structure that sets eukaryotic cells apart from prokaryotic cells is the nucleus, or nuclear...
s, bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
, and archea.
Gene
CARKD is located on Chromosome 13 in humans. The following genes are near CARKD on the chromosome:- COL4A2COL4A2Collagen alpha-2 chain is a protein that in humans is encoded by the COL4A2 gene.-Further reading:...
: A2 Subunit of type IV collagen - RAB20: Potential regulator of Connexin 43 trafficking.
- CARS2: Mitochondrial Cystienyl-tRNA Synthetase 2
- ING1ING1Inhibitor of growth protein 1 is a protein that in humans is encoded by the ING1 gene.-Location on Chromosome 13:ING1 is located near the following genes on Chromosome 13*CARKD Carbohydrate Kinase Domain-Containing Protein...
: Tumor-Suppressor Protein
Structure
This protein is part of the phosphomethylpyrimidine kinasePhosphomethylpyrimidine kinase
In enzymology, a phosphomethylpyrimidine kinase is an enzyme that catalyzes the chemical reactionThus, the two substrates of this enzyme are ATP and methyl phosphate, whereas its two products are ADP and methyl diphosphate.This enzyme belongs to the family of transferases, to be specific, those...
: ribokinase
Ribokinase
In enzymology, a ribokinase is an enzyme that catalyzes the chemical reactionThus, the two substrates of this enzyme are ATP and D-ribose, whereas its two products are ADP and D-ribose 5-phosphate....
/ pfkB superfamily. This family is characterized by the presence of a domain
Protein domain
A protein domain is a part of protein sequence and structure that can evolve, function, and exist independently of the rest of the protein chain. Each domain forms a compact three-dimensional structure and often can be independently stable and folded. Many proteins consist of several structural...
shared by the family. CARKD contains a carbohydrate kinase domain . This family is related to and implying that it also is a carbohydrate kinase.
Predicted properties
The following properties of CARKD were predicted using bioinformatic analysisBioinformatics
Bioinformatics is the application of computer science and information technology to the field of biology and medicine. Bioinformatics deals with algorithms, databases and information systems, web technologies, artificial intelligence and soft computing, information and computation theory, software...
:
- Molecular Weight: 41.4 KDal
- Isoelectric pointIsoelectric pointThe isoelectric point , sometimes abbreviated to IEP, is the pH at which a particular molecule or surface carries no net electrical charge....
: 9.377- CARKD orthologs have highly variable isoelectric points.
- Post-translational modificationPosttranslational modificationPosttranslational modification is the chemical modification of a protein after its translation. It is one of the later steps in protein biosynthesis, and thus gene expression, for many proteins....
: Three post-translational modifications are predicted:- Modified PhosphotyrosineTyrosineTyrosine or 4-hydroxyphenylalanine, is one of the 22 amino acids that are used by cells to synthesize proteins. Its codons are UAC and UAU. It is a non-essential amino acid with a polar side group...
Residue - Two N-Linked Glycosylation Sites
- Modified Phosphotyrosine
- A Signal PeptideSignal peptideA signal peptide is a short peptide chain that directs the transport of a protein.Signal peptides may also be called targeting signals, signal sequences, transit peptides, or localization signals....
and signal peptide cleavage site was predicted.
Tissue distribution
CARKD appears to be ubiquitously expressed at high levels. Expression data in the human protein, and the mouse ortholog, indicate its expression in almost all tissues. One peculiar expression pattern of CARKD is its differential expression through the development of oligodendrocyteOligodendrocyte
Oligodendrocytes , or oligodendroglia , are a type of brain cell. They are a variety of neuroglia. Their main function is the insulation of axons in the central nervous system of some vertebrates...
s. Its expression is lower in oligodendrocyte progenitor cells than in mature oligodendrocytes.
Binding partners
The human protein apolipoprotein A-1 binding precursor (APOA1BPAPOA1BP
Apolipoprotein A-I-binding protein also known as APOA1BP is a protein that in humans is encoded by the APOA1BP gene.- Function :APOA1BP binds to APOA1, APOA2, and high-density lipoprotein . In addition, APOA1BP appears to play a role in sperm capacitation....
) was predicted to be a binding partner for CARKD. This prediction is based on co-occurrence across genomes and co-expression. In addition to these data, the orthologs of CARKD in E. coli
Escherichia coli
Escherichia coli is a Gram-negative, rod-shaped bacterium that is commonly found in the lower intestine of warm-blooded organisms . Most E. coli strains are harmless, but some serotypes can cause serious food poisoning in humans, and are occasionally responsible for product recalls...
contain a domain similar to APOA1BP. This indicates that the two proteins are likely to have originated from a common evolutionary ancestor and, according to Rosetta stone analysis theory, are likely interaction partners even in species such as humans where the two proteins are not produced as a single polypeptide.
Clinical signficance
Based on allele-specific expression of CARKD, CARKD may play a role in acute lymphoblastic leukemiaAcute lymphoblastic leukemia
Acute lymphoblastic leukemia is a form of leukemia, or cancer of the white blood cells characterized by excess lymphoblasts.Malignant, immature white blood cells continuously multiply and are overproduced in the bone marrow. ALL causes damage and death by crowding out normal cells in the bone...
. In addition, microarray
DNA microarray
A DNA microarray is a collection of microscopic DNA spots attached to a solid surface. Scientists use DNA microarrays to measure the expression levels of large numbers of genes simultaneously or to genotype multiple regions of a genome...
data indicates that CARKD is up-regulated in Glioblastoma multiforme
Glioblastoma multiforme
Glioblastoma multiforme is the most common and most aggressive malignant primary brain tumor in humans, involving glial cells and accounting for 52% of all functional tissue brain tumor cases and 20% of all intracranial tumors. Despite being the most prevalent form of primary brain tumor, GBMs...
tumors.