CXCL14
Encyclopedia
Chemokine ligand 14 (CXCL14) is a small cytokine
belonging to the CXC chemokine
family that is also known as BRAK (for breast and kidney-expressed chemokine). Mature CXCL14 has many of the conserved features of the CXC chemokine subfamily but has some differences too, such as a shorter N-terminus and five extra amino acids in the region between its third and fourth cysteine
s. CXCL14 is constitutively expressed at high levels in many normal tissues, where its cellular source is thought to be fibroblast
s.
However, it is reduced or absent from most cancer cell
s. This chemokine is chemotactic for monocyte
s and can activate these cells in the presence of an inflammatory
mediator called prostaglandin-E2
(PGE2). It is also a potent chemoattractant and activator of dendritic cell
s, is implicated in homing of these cells, and can stimulate the migration of activated NK cells. CXCL14 also inhibits angiogenesis
, possibly as a result of its ability to block endothelial cell chemotaxis
. The gene
for CXCL14 contains four exon
s and is located on chromosome 5 in humans.
Cytokine
Cytokines are small cell-signaling protein molecules that are secreted by the glial cells of the nervous system and by numerous cells of the immune system and are a category of signaling molecules used extensively in intercellular communication...
belonging to the CXC chemokine
Chemokine
Chemokines are a family of small cytokines, or proteins secreted by cells. Their name is derived from their ability to induce directed chemotaxis in nearby responsive cells; they are chemotactic cytokines...
family that is also known as BRAK (for breast and kidney-expressed chemokine). Mature CXCL14 has many of the conserved features of the CXC chemokine subfamily but has some differences too, such as a shorter N-terminus and five extra amino acids in the region between its third and fourth cysteine
Cysteine
Cysteine is an α-amino acid with the chemical formula HO2CCHCH2SH. It is a non-essential amino acid, which means that it is biosynthesized in humans. Its codons are UGU and UGC. The side chain on cysteine is thiol, which is polar and thus cysteine is usually classified as a hydrophilic amino acid...
s. CXCL14 is constitutively expressed at high levels in many normal tissues, where its cellular source is thought to be fibroblast
Fibroblast
A fibroblast is a type of cell that synthesizes the extracellular matrix and collagen, the structural framework for animal tissues, and plays a critical role in wound healing...
s.
However, it is reduced or absent from most cancer cell
Cancer cell
Cancer cells are cells that grow and divide at an unregulated, quickened pace. Although cancer cells can be quite common in a person they are only malignant when the other cells fail to recognize and/or destroy them. In the past a common belief was that cancer cells failed to be recognized and...
s. This chemokine is chemotactic for monocyte
Monocyte
Monocytes are a type of white blood cell and are part of the innate immune system of vertebrates including all mammals , birds, reptiles, and fish. Monocytes play multiple roles in immune function...
s and can activate these cells in the presence of an inflammatory
Inflammation
Inflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...
mediator called prostaglandin-E2
Prostaglandin
A prostaglandin is any member of a group of lipid compounds that are derived enzymatically from fatty acids and have important functions in the animal body. Every prostaglandin contains 20 carbon atoms, including a 5-carbon ring....
(PGE2). It is also a potent chemoattractant and activator of dendritic cell
Dendritic cell
Dendritic cells are immune cells forming part of the mammalian immune system. Their main function is to process antigen material and present it on the surface to other cells of the immune system. That is, dendritic cells function as antigen-presenting cells...
s, is implicated in homing of these cells, and can stimulate the migration of activated NK cells. CXCL14 also inhibits angiogenesis
Angiogenesis
Angiogenesis is the physiological process involving the growth of new blood vessels from pre-existing vessels. Though there has been some debate over terminology, vasculogenesis is the term used for spontaneous blood-vessel formation, and intussusception is the term for the formation of new blood...
, possibly as a result of its ability to block endothelial cell chemotaxis
Chemotaxis
Chemotaxis is the phenomenon in which somatic cells, bacteria, and other single-cell or multicellular organisms direct their movements according to certain chemicals in their environment. This is important for bacteria to find food by swimming towards the highest concentration of food molecules,...
. The gene
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
for CXCL14 contains four exon
Exon
An exon is a nucleic acid sequence that is represented in the mature form of an RNA molecule either after portions of a precursor RNA have been removed by cis-splicing or when two or more precursor RNA molecules have been ligated by trans-splicing. The mature RNA molecule can be a messenger RNA...
s and is located on chromosome 5 in humans.