XK (protein) | |||||||
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Identifiers | |||||||
Symbol | XK | ||||||
Alt. symbols | XKR1, Kx, X1k | ||||||
NCBI gene | 7504 | ||||||
HGNC | 12811 | ||||||
OMIM | 314850 | ||||||
PDB | BAE48708 | ||||||
RefSeq | NM_021083 | ||||||
UniProt | P51811 | ||||||
Other data | |||||||
Locus | Chr. X p21.2-p21.1 | ||||||
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XK (also known as Kell blood group precursor) is a protein found on human red blood cells and other tissues which is responsible for the Kx antigen which helps determine a person's blood type.
The Kx antigen plays a role in matching blood for blood transfusions.[ citation needed ]
Mutation of XK protein may lead to McLeod syndrome, [1] a multi-system disorder characterized by hemolytic anemia, myopathy, acanthocytosis, and chorea. [2]
XK is located on the X chromosome (cytogenetic band Xp21.1) and absence of the XK protein is an X-linked disease. [3]
XK is a membrane transport protein of unknown action. [4]
Duffy antigen/chemokine receptor (DARC), also known as Fy glycoprotein (FY) or CD234, is a protein that in humans is encoded by the ACKR1 gene.
Chorea-acanthocytosis, is a rare hereditary disease caused by a mutation in a gene that directs structural proteins in red blood cells. It belongs to a group of four diseases characterized under the name neuroacanthocytosis. When a patient's blood is viewed under a microscope, some of the red blood cells appear thorny. These thorny cells are called acanthocytes.
Neuroacanthocytosis is a label applied to several genetic neurological conditions in which the blood contains misshapen, spiculated red blood cells called acanthocytes.
The term human blood group systems is defined by International Society of Blood Transfusion as systems in the human species where cell-surface antigens—in particular, those on blood cells—are "controlled at a single gene locus or by two or more very closely linked homologous genes with little or no observable recombination between them", and include the common ABO and Rh (Rhesus) antigen systems, as well as many others; 38 major human systems are identified as of August 2019.
The Kell antigen system is a human blood group system, that is, group of antigens on the human red blood cell surface which are important determinants of blood type and are targets for autoimmune or alloimmune diseases which destroy red blood cells. The Kell antigens are K, k, Kpa, Kpb, Jsa and Jsb. The Kell antigens are peptides found within the Kell protein, a 93-kilodalton transmembrane zinc-dependent endopeptidase which is responsible for cleaving endothelin-3.
The Rh blood group system is a human blood group system. It contains proteins on the surface of red blood cells. After the ABO blood group system, it is the most likely to be involved in transfusion reactions. The Rh blood group system consists of 49 defined blood group antigens, among which the five antigens D, C, c, E, and e are the most important. There is no d antigen. Rh(D) status of an individual is normally described with a positive or negative suffix after the ABO type. The terms Rh factor, Rh positive, and Rh negative refer to the Rh(D) antigen only. Antibodies to Rh antigens can be involved in hemolytic transfusion reactions and antibodies to the Rh(D) and Rh antigens confer significant risk of hemolytic disease of the fetus and newborn.
McLeod syndrome is an X-linked recessive genetic disorder that may affect the blood, brain, peripheral nerves, muscle, and heart. It is caused by a variety of recessively inherited mutations in the XK gene on the X chromosome. The gene is responsible for producing the Kx protein, a secondary supportive protein for the Kell antigen on the red blood cell surface.
P1PK is a human blood group system based upon the A4GALT gene on chromosome 22. The P antigen was first described by Karl Landsteiner and Philip Levine in 1927. The P1PK blood group system consists of three glycosphingolipid antigens: Pk, P1 and NOR. In addition to glycosphingolipids, terminal Galα1→4Galβ structures are present on complex-type N-glycans. The GLOB antigen is now the member of the separate GLOB blood group system.
Mitochondrially encoded tRNA leucine 1 (UUA/G) also known as MT-TL1 is a transfer RNA which in humans is encoded by the mitochondrial MT-TL1 gene.
Tropomyosin alpha-3 chain is a protein that in humans is encoded by the TPM3 gene.
Glycophorin A , also known as GYPA, is a protein which in humans is encoded by the GYPA gene. GYPA has also recently been designated CD235a.
Rh-associated glycoprotein (RHAG) is an ammonia transporter protein that in humans is encoded by the RHAG gene. RHAG has also recently been designated CD241. Mutations in the RHAG gene can cause stomatocytosis.
Homeobox protein Hox-A13 is a protein that in humans is encoded by the HOXA13 gene.
VPS13A is a protein that in humans is encoded by the VPS13A gene.
Erythroid membrane-associated protein is a protein that in humans is responsible for the Scianna blood group system, and is encoded by the ERMAP gene.
Mitochondrially encoded tRNA valine also known as MT-TV is a transfer RNA which in humans is encoded by the mitochondrial MT-TV gene.
Mitochondrially encoded tRNA tryptophan also known as MT-TW is a transfer RNA which in humans is encoded by the mitochondrial MT-TW gene.
The KX Blood-group Antigen (KXA) Family (TC# 2.A.112) consists of transport proteins that are part of the TOG superfamily. The KX gene codes for a novel protein with characteristics of membrane transporters that has been proposed to be a Na+ -dependent neutral amine and/or oligopeptide transporter. It is predicted to be 444 amino acyl residues in length and exhibits 10 putative transmembrane α-helical segments. The KX blood group antigen mRNA expression pattern correlates with McLeod syndrome.
Xp11.2 duplication is a genomic variation marked by the duplication of an X chromosome region on the short arm p at position 11.2, defined by standard karyotyping (G-banding). This gene-rich, rearrangement prone region can be further divided into three loci - Xp11.21, Xp11.22 and Xp11.23. The duplication could involve any combination of these three loci. While the length of the duplication can vary from 0.5Mb to 55 Mb, most duplications measure about 4.5Mb and typically occur in the region of 11.22-11.23. Most affected females show preferential activation of the duplicated X chromosome. Features of affected individuals vary significantly, even among members of the same family. The Xp11.2 duplication can be 'silent' - presenting no obvious symptoms in carriers - which is known from the asymptomatic parents of affected children carrying the duplication. The common symptoms include intellectual disabilities, speech delay and learning difficulties, while in rare cases, children have seizures and a recognizable brain wave pattern when assessed by EEG (electroencephalography).
The Augustine blood group system is a human blood group system. It includes four red blood cell surface glycoprotein antigens which are encoded by alleles of the gene SLC29A1.