| Lectin C-type domain | |||||||||
|---|---|---|---|---|---|---|---|---|---|
 | |||||||||
| Identifiers | |||||||||
| Symbol | Lectin_C | ||||||||
| Pfam | PF00059 | ||||||||
| InterPro | IPR001304 | ||||||||
| SMART | CLECT | ||||||||
| PROSITE | PS50041 | ||||||||
| SCOP2 | 2msb / SCOPe / SUPFAM | ||||||||
| CDD | cd00037 | ||||||||
| Membranome | 52 | ||||||||
| |||||||||
A C-type lectin (CLEC) is a type of carbohydrate-binding protein known as a lectin. [3] The C-type designation is from their requirement for calcium for binding. [4] Proteins that contain C-type lectin domains have a diverse range of functions including cell-cell adhesion, immune response to pathogens and apoptosis. [5] [6]
Drickamer et al. classified C-type lectins into 7 subgroups (I to VII) based on the order of the various protein domains in each protein. [7] This classification was subsequently updated in 2002, leading to seven additional groups (VIII to XIV). [8] Most recently, three further subgroups were added (XV to XVII). [3]
| Group | Name | Associated domains |
|---|---|---|
| I | Lecticans | EGF, Sushi, Ig and Link domains |
| II | Asialoglycoprotein and DC receptors | None |
| III | Collectins | None |
| IV | Selectins | Sushi and EGF domains |
| V | NK - cell receptors | None |
| VI | Multi-CTLD endocytic receptors | FnII and Ricin domains |
| VII | Reg group | None |
| VIII | Chondrolectin, Layilin | None |
| IX | Tetranectin | None |
| X | Polycystin | WSC, REJ, PKD domains |
| XI | Attractin (ATRN) | PSI, EGF and CUB domains |
| XII | Eosinophil major basic protein (EMBP) | None |
| XIII | DGCR2 | None |
| XIV | Thrombomodulin, CD93, CD248, CLEC14A | EGF domains [9] |
| XV | Bimlec | None |
| XVI | SEEC | SCP and EGF domains |
| XVII | CBCP/Frem1/QBRICK | CSPG repeats and CalX-beta domains |
CLECs include:
The "NK Cell lectin-like receptors" are a very closely related group: [10]
Additional proteins containing this domain include:
Scavenger receptors are a large and diverse superfamily of cell surface receptors. Its properties were first recorded in 1970 by Drs. Brown and Goldstein, with the defining property being the ability to bind and remove modified low density lipoproteins (LDL). Today scavenger receptors are known to be involved in a wide range of processes, such as: homeostasis, apoptosis, inflammatory diseases and pathogen clearance. Scavenger receptors are mainly found on myeloid cells and other cells that bind to numerous ligands, primarily endogenous and modified host-molecules together with pathogen-associated molecular patterns(PAMPs), and remove them. The Kupffer cells in the liver are particularly rich in scavenger receptors, includes SR-A I, SR-A II, and MARCO.
DC-SIGN also known as CD209 is a protein which in humans is encoded by the CD209 gene.
Collectins (collagen-containing C-type lectins) are a part of the innate immune system. They form a family of collagenous Ca2+-dependent defense lectins, which are found in animals. Collectins are soluble pattern recognition receptors (PRRs). Their function is to bind to oligosaccharide structure or lipids that are on the surface of microorganisms. Like other PRRs they bind pathogen-associated molecular patterns (PAMPs) and danger-associated molecular patterns (DAMPs) of oligosaccharide origin. Binding of collectins to microorganisms may trigger elimination of microorganisms by aggregation, complement activation, opsonization, activation of phagocytosis, or inhibition of microbial growth. Other functions of collectins are modulation of inflammatory, allergic responses, adaptive immune system and clearance of apoptotic cells.
CD94, also known as killer cell lectin-like receptor subfamily D, member 1 (KLRD1) is a human gene.
Oxidized low-density lipoprotein receptor 1 also known as lectin-type oxidized LDL receptor 1 (LOX-1) is a protein that in humans is encoded by the OLR1 gene.
C-type lectin domain family 4 member M is a protein that in humans is encoded by the CLEC4M gene. CLEC4M has also been designated as CD299.
CD93 is a protein that in humans is encoded by the CD93 gene. CD93 is a C-type lectin transmembrane receptor which plays a role not only in cell–cell adhesion processes but also in host defense.
C-type lectin domain family 7 member A or Dectin-1 is a protein that in humans is encoded by the CLEC7A gene. CLEC7A is a member of the C-type lectin/C-type lectin-like domain (CTL/CTLD) superfamily. The encoded glycoprotein is a small type II membrane receptor with an extracellular C-type lectin-like domain fold and a cytoplasmic domain with a partial immunoreceptor tyrosine-based activation motif. It functions as a pattern-recognition receptor for a variety of β-1,3-linked and β-1,6-linked glucans from fungi and plants, and in this way plays a role in innate immune response. Expression is found on myeloid dendritic cells, monocytes, macrophages and B cells. Alternate transcriptional splice variants, encoding different isoforms, have been characterized. This gene is closely linked to other CTL/CTLD superfamily members on chromosome 12p13 in the natural killer gene complex region.
NKG2-C type II integral membrane protein or NKG2C is a protein that in humans is encoded by the KLRC2 gene. It is also known as or cluster of differentiation 159c (CD159c).
C-type lectin domain family 11 member A is a protein that in humans is encoded by the CLEC11A gene.
C-type lectin domain family 1 member B is a protein that in humans is encoded by the CLEC1B gene.
Endosialin is a protein that in humans is encoded by the CD248 gene.
C-type lectin domain family 2 member D is a protein that in humans is encoded by the CLEC2D gene.
C-type lectin domain family 4 member A is a protein that in humans is encoded by the CLEC4A gene.
C-type lectin domain family 1 member A is a protein that in humans is encoded by the CLEC1A gene.
C-type lectin domain family 2 member B is a protein that in humans is encoded by the CLEC2B gene.
C-type lectin domain family 12 member A is a protein that in humans is encoded by the CLEC12A gene.
The following outline is provided as an overview of and topical guide to immunology:
C-type lectin domain family 10 member A also known as CLEC10A is a protein that in humans is encoded by the CLEC10A gene.
C-type lectin domain family 5 member A (CLEC5A), also known as C-type lectin superfamily member 5 (CLECSF5) and myeloid DAP12-associating lectin 1 (MDL-1) is a C-type lectin that in humans is encoded by the CLEC5A gene.