Chemokine (C-C motif) ligand 28 (CCL28), also known as mucosae-associated epithelial chemokine (MEC), CCK1 and SCYA28, is a

chemokine Chemokines (), or chemotactic cytokines, are a family of small cytokines or signaling proteins secreted by cells that induce directional movement of leukocytes, as well as other cell types, including endothelial and epithelial cells. In additi ...

. CCL28 regulates the

chemotaxis Chemotaxis (from '' chemo-'' + '' taxis'') is the movement of an organism or entity in response to a chemical stimulus. Somatic cells, bacteria, and other single-cell or multicellular organisms direct their movements according to certain chemica ...

of cells that express the

chemokine receptor Chemokine receptors are cytokine receptors found on the surface of certain cells that interact with a type of cytokine called a chemokine. There have been 20 distinct chemokine receptors discovered in humans. Each has a rhodopsin-like 7-trans ...

s CCR3 and

CCR10 C-C chemokine receptor type 10 is a protein that in humans is encoded by the ''CCR10'' gene. Function Chemokines are a group of small (approximately 8 to 14 kD), mostly basic, structurally related molecules that regulate cell trafficking of va ...

. CCL28 is expressed by columnar epithelial cells in the gut,

lung The lungs are the primary organs of the respiratory system in humans and most other animals, including some snails and a small number of fish. In mammals and most other vertebrates, two lungs are located near the backbone on either side of ...

breast The breast is one of two prominences located on the upper ventral region of a primate's torso. Both females and males develop breasts from the same embryological tissues. In females, it serves as the mammary gland, which produces and sec ...

and the

salivary gland The salivary glands in mammals are exocrine glands that produce saliva through a system of ducts. Humans have three paired major salivary glands ( parotid, submandibular, and sublingual), as well as hundreds of minor salivary glands. Salivary ...

s and drives the mucosal homing of T and

B lymphocyte B cells, also known as B lymphocytes, are a type of white blood cell of the lymphocyte subtype. They function in the humoral immunity component of the adaptive immune system. B cells produce antibody molecules which may be either secreted or ...

s that express CCR10, and the migration of

eosinophil Eosinophils, sometimes called eosinophiles or, less commonly, acidophils, are a variety of white blood cells (WBCs) and one of the immune system components responsible for combating multicellular parasites and certain infections in vertebrates. A ...

s expressing CCR3. This chemokine is constitutively expressed in the colon, but its levels can be increased by pro-inflammatory

cytokine Cytokines are a broad and loose category of small proteins (~5–25 kDa) important in cell signaling. Cytokines are peptides and cannot cross the lipid bilayer of cells to enter the cytoplasm. Cytokines have been shown to be involved in au ...

s and certain bacterial products implying a role in effector cell recruitment to sites of epithelial injury. CCL28 has also been implicated in the migration of

IgA Iga may refer to: Arts and entertainment * Ambush at Iga Pass, a 1958 Japanese film * Iga no Kagemaru, Japanese manga series * Iga, a set of characters from the Japanese novel '' The Kouga Ninja Scrolls'' Biology * ''Iga'' (beetle), a g ...

-expressing cells to the

mammary gland A mammary gland is an exocrine gland in humans and other mammals that produces milk to feed young offspring. Mammals get their name from the Latin word ''mamma'', "breast". The mammary glands are arranged in organs such as the breasts in ...

intestine The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organs of the digestive system, in humans an ...

and other mucosal tissues. It has also been shown as a potential

antimicrobial An antimicrobial is an agent that kills microorganisms or stops their growth. Antimicrobial medicines can be grouped according to the microorganisms they act primarily against. For example, antibiotics are used against bacteria, and antifungals ar ...

agent effective against certain pathogens, such as

Gram negative The gram (originally gramme; SI unit symbol g) is a unit of mass in the International System of Units (SI) equal to one one thousandth of a kilogram. Originally defined as of 1795 as "the absolute weight of a volume of pure water equal to th ...

and

Gram positive In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall. Gram-positive bact ...

bacteria and the fungus ''

Candida albicans ''Candida albicans'' is an opportunistic pathogenic yeast that is a common member of the human gut flora. It can also survive outside the human body. It is detected in the gastrointestinal tract and mouth in 40–60% of healthy adults. It is usu ...

''. Human CCL28 is encoded by an RNA transcript of 373

nucleotide Nucleotides are organic molecules consisting of a nucleoside and a phosphate. They serve as monomeric units of the nucleic acid polymers – deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), both of which are essential biomolecu ...

s and a gene with four

exon An exon is any part of a gene that will form a part of the final mature RNA produced by that gene after introns have been removed by RNA splicing. The term ''exon'' refers to both the DNA sequence within a gene and to the corresponding sequen ...

s. The gene codes for a 127-amino acid CCL28 protein with a 22-amino acid

N-terminal The N-terminus (also known as the amino-terminus, NH2-terminus, N-terminal end or amine-terminus) is the start of a protein or polypeptide, referring to the free amine group (-NH2) located at the end of a polypeptide. Within a peptide, the ami ...

signal peptide A signal peptide (sometimes referred to as signal sequence, targeting signal, localization signal, localization sequence, transit peptide, leader sequence or leader peptide) is a short peptide (usually 16-30 amino acids long) present at the N-te ...

. It shares 76% nucleic acid identity and 83% amino acid similarity to the equivalent molecule in mouse. Sequence analysis has revealed CCL28 to be most similar to another CC chemokine called CCL27.

Gene neighbourhood

The gene '' C5orf34'' is found downstream of ''CCL28'' and is a predicted to be in the Polo-like Kinase family. '' C5orf34'' extends from base pair 43,486,701 to base pair 43,515,445.

References

{{DEFAULTSORT:Ccl28 Cytokines