C-type lectin

A C-type lectin (CLEC) is a type of carbohydrate-binding protein domain known as a lectin. The C-type designation is from their requirement for calcium 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 each protein. This classification was subsequently updated in 2002, leading to seven additional groups (VIII to XIV). Most recently a further three subgroups were added (XV to XVII).

CLECs include:


 * CLEC1A, CLEC1B
 * CLEC2A, CLEC2B, CD69 (CLEC2C), CLEC2D, CLEC2L
 * CLEC3A, CLEC3B
 * CLEC4A, CLEC4C, CLEC4D, CLEC4E, CLEC4F, CLEC4G, ASGR1 (CLEC4H1), ASGR2 (CLEC4H2), FCER2 (CLEC4J), CD207 (CLEC4K), CD209 (CLEC4L), CLEC4M
 * CLEC5A
 * CLEC6A
 * CLEC7A
 * OLR1 (CLEC8A)
 * CLEC9A
 * CLEC10A
 * CLEC11A
 * CLEC12A, CLEC12B
 * CD302 (CLEC13A), LY75 (CLEC13B), PLA2R1 (CLEC13C), MRC1 (CLEC13D), MRC2 (CLEC13E)
 * CLEC14A
 * CLEC16A
 * CLEC17A

The "NK Cell lectin-like receptors" are a very closely related group:
 * KLRA1
 * KLRB1 (CLEC5B)
 * KLRC1, KLRC2, KLRC3, KLRC4
 * KLRD1
 * KLRF1 (CLEC5C)
 * KLRG1 (CLEC15A), KLRG2 (CLEC15B)
 * KLRK1

Additional proteins containing this domain include:


 * AGC1; ATRNL1
 * BCAN
 * CD248; CD72; CD93; CHODL; CL-K1-Ia; CL-K1-Ib; CL-K1-Ic; CLECSF5; COLEC10; COLEC11; COLEC12; CSPG3
 * FCER2; FREM1; HBXBP;
 * LAYN; LOC348174; LOC728276
 * MAFA; MBL2; MGC34761; MICL; MRC1L1
 * OLR1
 * PAP; PKD1; PKD1L2; PLA2R1; PRG2; PRG3
 * REG1A; REG1B; REG3A; REG3G; REG4
 * SELE; SELL; SELP; SFTPA1; SFTPA2; SFTPA2B; SFTPD; SRCL
 * THBD
 * VCAN