A C-type lectin (CLEC) is a type of carbohydrate-binding

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, respon ...

known as a

lectin Lectins are carbohydrate-binding proteins that are highly specific for sugar groups that are part of other molecules, so cause agglutination of particular cells or precipitation of glycoconjugates and polysaccharides. Lectins have a role in rec ...

. The C-type designation is from their requirement for

calcium Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar t ...

for binding. Proteins that contain C-type lectin domains have a diverse range of functions including cell-cell adhesion, immune response to pathogens and apoptosis.

Classification

Drickamer ''et al.'' classified C-type lectins into 7 subgroups (I to VII) based on the order of the various

protein domains In molecular biology, a protein domain is a region of a protein's polypeptide chain that is self-stabilizing and that folds independently from the rest. Each domain forms a compact folded three-dimensional structure. Many proteins consist of se ...

in each protein. This classification was subsequently updated in 2002, leading to seven additional groups (VIII to XIV). Most recently, three further subgroups were added (XV to XVII). CLECs include: * CLEC1A,

CLEC1B C-type lectin domain family 1 member B is a protein that in humans is encoded by the ''CLEC1B'' gene. Natural killer (NK) cells express multiple calcium-dependent (C-type) lectin-like receptors, such as CD94 (KLRD1; MIM 602894) and NKG2D (KLRC4; M ...

CLEC2A CLEC or Clec may refer to: * ''Clec'' (album), a 1995 album by Perfect Houseplants, co-founded by Huw Warren *Colonial Land and Emigration Commission, a British government authority that existed from the 1840s to 1878 *Competitive local exchange ca ...

CLEC2B C-type lectin domain family 2 member B is a protein that in humans is encoded by the ''CLEC2B'' gene. This gene encodes a member of the C-type lectin/C-type lectin-like domain (CTL/CTLD) protein superfamily. Members of this family share a common p ...

CD69 CD69 (Cluster of Differentiation 69) is a human transmembrane C-Type lectin protein encoded by the gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ...

(CLEC2C), CLEC2D,

CLEC2L CLEC or Clec may refer to: * ''Clec'' (album), a 1995 album by Perfect Houseplants, co-founded by Huw Warren *Colonial Land and Emigration Commission, a British government authority that existed from the 1840s to 1878 *Competitive local exchange c ...

* CLEC3A,

CLEC3B Tetranectin is a protein that in humans is encoded by the ''CLEC3B'' gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ...

* CLEC4A, CLEC4C, CLEC4D, CLEC4E, CLEC4F, CLEC4G,

ASGR1 Asialoglycoprotein receptor 1 is a protein that in humans is encoded by the ASGR1 gene. Function This gene encodes a subunit of the asialoglycoprotein receptor. This receptor is a transmembrane protein that plays a critical role in serum g ...

(CLEC4H1),

ASGR2 The asialoglycoprotein receptors (ASGPR) are lectins which bind asialoglycoprotein and glycoproteins from which a sialic acid has been removed to expose galactose residues. The receptors, which are integral membrane proteins and are located on ...

(CLEC4H2),

FCER2 CD23, also known as Fc epsilon RII, or FcεRII, is the "low-affinity" receptor for IgE, an antibody isotype involved in allergy and resistance to parasites, and is important in regulation of IgE levels. Unlike many of the antibody receptors, CD23 ...

(CLEC4J),

CD207 Langerin (CD207) is a type II transmembrane protein which is encoded by the ''CD207'' gene in humans. It was discovered by scientists Sem Saeland and Jenny Valladeau as a main part of Birbeck granules. Langerin is C-type lectin receptor on La ...

(CLEC4K), CD209 (CLEC4L), CLEC4M * CLEC5A *

CLEC6A Dectin-2 or C-type lectin domain containing 6A is a protein that in humans is encoded by the CLEC6A gene. Dectin-2 is a member of the C-type lectin/C-type lectin-like domain (CTL/CTLD) superfamily. The encoded protein is a type II transmembrane pro ...

* CLEC7A * OLR1 (CLEC8A) * CLEC9A * CLEC10A * CLEC11A *

CLEC12A C-type lectin domain family 12 member A is a protein that in humans is encoded by the ''CLEC12A'' gene. This gene encodes a member of the C-type lectin/C-type lectin-like domain (CTL/CTLD) superfamily. Members of this family share a common protei ...

, CLEC12B * CD302 (CLEC13A),

LY75 CD205 also called Lymphocyte antigen 75 is a protein that in humans is encoded by the ''LY75'' gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''ge ...

(CLEC13B),

PLA2R1 Secretory phospholipase A2 receptor is a protein that in humans is encoded by the ''PLA2R1'' gene. Clinical significance M-type phospholipase A2 receptor is the major antigen in idiopathic membranous nephropathy Membranous glomerulonephritis ...

(CLEC13C),

MRC1 The mannose receptor (Cluster of Differentiation 206, CD206) is a C-type lectin primarily present on the surface of macrophages, immature dendritic cells and liver sinusoidal endothelial cells, but is also expressed on the surface of skin cells ...

(CLEC13D),

MRC2 The mannose receptor (Cluster of Differentiation 206, CD206) is a C-type lectin primarily present on the surface of macrophages, immature dendritic cells and liver sinusoidal endothelial cells, but is also expressed on the surface of skin cells ...

(CLEC13E) * CLEC14A *

CLEC16A C-type lectin domain family 16, also known as CLEC16A, is a protein that in humans is encoded by the ''CLEC16A'' gene. Function Little is known regarding the function of the CLEC16A protein, however it is shown to be highly expressed on B-l ...

* CLEC17A The "NK Cell lectin-like receptors" are a very closely related group: *

KLRA1 Killer cell lectin-like receptor subfamily A (KLRA, alternative nomenclature Ly49) is a gene cluster coding proteins from family Ly49, which are membrane receptors expressed mainly on the surface of NK cells and other cells of immune system in s ...

* KLRB1 (CLEC5B) * KLRC1, KLRC2, KLRC3,

KLRC4 NKG2-F type II integral membrane protein is a protein that in humans is encoded by the ''KLRC4'' gene. Natural killer (NK) cells are lymphocytes that can mediate lysis of certain tumor cells and virus-infected cells without previous activation. T ...

KLRD1 CD94 (Cluster of Differentiation 94), also known as killer cell lectin-like receptor subfamily D, member 1 (KLRD1) is a human gene. The protein encoded by CD94 gene is a lectin, cluster of differentiation and a receptor that is involved in cell s ...

* KLRF1 (CLEC5C) *

KLRG1 Killer cell lectin-like receptor subfamily G member 1 is a protein that in humans is encoded by the ''KLRG1'' gene. Function Natural killer (NK) cells are lymphocytes that can mediate lysis of certain tumor cells and virus-infected cells witho ...

(CLEC15A),

KLRG2 KLRG (880 AM) is an American radio station broadcasting a classic rock format. It is licensed to Sheridan, Arkansas, and serves the Little Rock Metro area from its transmitter located 5 Miles from the Arkansas State Capitol. The station is own ...

(CLEC15B) * KLRK1 Additional proteins containing this domain include: * AGC1; ATRNL1 *

BCAN Brevican core protein is a protein that in humans is encoded by the ''BCAN'' gene. Brevican is a member of the lectican protein family. Brevican is localised to the surface of neurons in the brain. In melanocytic cells, BCAN gene expression ...

* CD248; CD72; CD93; CHODL; CL-K1-Ia; CL-K1-Ib; CL-K1-Ic; CLECSF5; COLEC10; COLEC11; COLEC12;

CSPG3 Neurocan core protein is a protein that in humans is encoded by the ''NCAN'' gene. Neurocan is a member of the lectican / chondroitin sulfate proteoglycan protein families and consists of neurocan core protein and chondroitin sulfate. It is thoug ...

; FREM1; HBXBP; *

LAYN Torah reading (; ') is a Jewish religious tradition that involves the public reading of a set of passages from a Torah scroll. The term often refers to the entire ceremony of removing the scroll (or scrolls) from the Torah ark, chanting the ap ...

; LOC348174; LOC728276 * MAFA;

MBL2 Mannose-binding lectin (MBL), also called mannan-binding lectin or mannan-binding protein (MBP), is a lectin that is instrumental in innate immunity as an opsonin and via the lectin pathway. Structure MBL has an oligomeric structure (400-700 kDa) ...

; MGC34761; MICL;

MRC1L1 The mannose receptor (Cluster of Differentiation 206, CD206) is a C-type lectin primarily present on the surface of macrophages, immature dendritic cells and liver sinusoidal endothelial cells, but is also expressed on the surface of skin cells ...

* OLR1 * PAP; PKD1; PKD1L2;

;

PRG2 Eosinophil major basic protein, often shortened to major basic protein (MBP; also called Proteoglycan 2 (PRG2)) is encoded in humans by the ''PRG2'' gene. Function The protein encoded by this gene is the predominant constituent of the crystall ...

; PRG3 *

REG1A Pancreatic Stone Protein (PSP), also known as Lithostathine-1-alpha islet cells regeneration factor (ICRF) or islet of Langerhans regenerating protein (REG) is a protein that in humans is encoded by the ''REG1A'' gene as a single polypeptide of 144 ...

;

REG1B Lithostathine-1-beta is a protein that in humans is encoded by the ''REG1B'' gene. Function This gene is a type I subclass member of the Reg gene family. The Reg gene family is a multigene family grouped into four subclasses, types I, II, III ...

; REG3A;

REG3G Regenerating islet-derived protein 3 gamma (also Regenerating islet-derived protein III-gamma) is a protein that in humans is encoded by the ''REG3G'' gene. Intestinal paneth cells produce REG3G (or REG3 gamma) via stimulation of toll-like recep ...

; REG4 *

SELE Sele may refer to: Places Africa * Sele, Burkina Faso, a village in the Ouéleni Department of Burkina Fase. * Sele, Ethiopia, a town in Agbe municipality Asia * Sele, Turkey, a Turkish village in Kailar in Ottoman times *Şələ, Azerbaijan *Se ...

;

SELL Sell can refer to: People * Brenda Sell (born 1955), American martial arts instructor and highest ranking non-Korean female practitioner of taekwondo * Brian Sell (born 1978), American retired long-distance runner * Edward Sell (priest) (1839– ...

;

SELP P-selectin is a type-1 transmembrane protein that in humans is encoded by the SELP gene. P-selectin functions as a cell adhesion molecule (CAM) on the surfaces of activated endothelial cells, which line the inner surface of blood vessels, and ...

; SFTPA1; SFTPA2; SFTPA2B; SFTPD; SRCL *

THBD Thrombomodulin (TM), CD141 or BDCA-3 is an integral membrane protein expressed on the surface of endothelial cells and serves as a cofactor for thrombin. It reduces blood coagulation by converting thrombin to an anticoagulant enzyme from a procoa ...

VCAN Versican is a large extracellular matrix proteoglycan that is present in a variety of human tissues. It is encoded by the ''VCAN'' gene. Versican is a large chondroitin sulfate proteoglycan with an apparent molecular mass of more than 1000kDa. I ...

References

External links

Functional Glycomics Gateway
a collaboration between the

Consortium for Functional Glycomics The Consortium for Functional Glycomics (CFG) is a large research initiative funded in 2001 by a glue grant from the National Institute of General Medical Sciences (NIGMS) to “define paradigms by which protein- carbohydrate interactions medi ...

and

Nature Publishing Group Nature Portfolio (formerly known as Nature Publishing Group and Nature Research) is a division of the international scientific publishing company Springer Nature that publishes academic journals, magazines, online databases, and services in scie ...

{{DEFAULTSORT:C-Type Lectin Human proteins Protein domains Single-pass transmembrane proteins