From: Introduction to glycopathology: the concept, the tools and the perspectives
Activity | Example of lectin |
---|---|
Recognition of stem region of N-glycans, a signal for ubiquitin conjugation when accessible in incorrectly folded glycoproteins | F-box proteins Fbs1 and Fbs2, which comprise the ligand-specific part of SCFb ubiquitin ligase complexes |
Molecular chaperones with dual specificity for Glc2/Glc1Man9GlcN Ac2 and protein part of nascent glycoproteins in the ER | Malectin/ribophorin I complex, calnexin, calreticulin |
Targeting of misfolded glycoproteins with Man8-5GlcN Ac2 as carbohydrate ligand to ER-associated degradation (ERAD) | EDEM1,2c/Mnl1 (Htm1) (lectins or glycosidases?), Yos9p (MRHd domain) in yeast, erlectin (XTP3-Be) and OS-9f in mammals |
Intracellular routing of glycoproteins and vesicles and apical delivery | Comitin, ERGIC53g and VIP36h (probably also ERGLi and VIPLj), galectins-3, -4 and -9, P-type lectins |
Intracellular transport and extracellular assembly | Non-integrin 67 kDa elastin/laminin-binding protein |
Enamel formation and biomineralization | Amelogenin |
Inducer of membrane superimposition and zippering (formation of Birbeck granules) | Langerin (CD207) |
Cell type-specific endocytosis | Cysteine-rich domain (β-trefoil) of the dimeric form of mannose receptor for GalN Ac-4-SO4-bearing glycoprotein hormones in hepatic endothelial cells, dendritic cell and macrophage C-type lectins (mannose receptor family members (tandem-repeat type) and single-CRDk lectins such as trimeric langerin/CD207 or tetrameric DC-SIGNl/CD209), hepatic and macrophage asialoglycoprotein receptors, HAREm, P-type lectins |
Recognition of foreign glycans (β1,3-glucans, cell wall peptidoglycan, LOSn and LPSo), mycobacterial glycolipid or host-like epitopes | CR3p (CD11b/CD18, Mac-1 antigen), C-type lectins such as collectins, DC-SIGN, dectin-1, Mincle and RegIIIγ (murine)q or HIP/PAP (human), ficolins, galectins, immulectins, intelectins, Limulus coagulation factors C and G, siglecs, tachylectins |
Recognition of foreign or aberrant glycosignatures on cells (including endocytosis or initiation of opsonization or complement activation) and of apoptotic/necrotic cells (glycans or peptide motifs) | Collectins, C-type macrophage and dendritic cell lectins, CR3 (CD11b/CD18, Mac-1 antigen), α/Θ-defensins, ficolins, galectins, pentraxins (CRP, limulin), RegIIIγ (HIP/PAP), siglecs, tachylectins |
Targeting of enzymatic activity in multimodular proteins | Acrosin, Limulus coagulation factor C, laforin, β-trefoil fold ((QxW)3 domain) of GalN Ac-Tsr involved in mucin-type O-glycosylation, frequent in microbial glycosylhydrolases for plant cell wall polysaccharides, termed carbohydrate-binding modules |
Bridging of molecules | Cerebellar soluble lectin, cytokines (e.g. IL-2s–IL-2R and CD3 of TCR), galectins |
Induction or suppression of effector release (H2O2, cytokines etc.) | Chitinase-like YKL-40, galectins, I-type lectins (e.g. CD33 (siglec-3), siglecs-7 and -9), selectins and other C-type lectins such as CD23, BDCA2 and dectin-1, Toll-like receptor 4 |
Alteration of enzymatic activities in modular proteins/receptor endocytosis via lattice formation | Mannan-binding lectin (acting on meprins); galectins |
Cell growth control, induction of apoptosis/anoikis and axonal regeneration | Amphoterin and other heparin-binding proteins, cerebellar soluble lectin, chitinase-like lectins, C-type lectins, galectins, hyaluronic acid-binding proteins, siglecs (e.g. CD22 and CD33) |
Cell migration and routing | Galectins, hyaluronic acid-binding proteins (CD44, hyalectans/lecticans, RHAMMt), I-type lectins, selectins and other C-type lectins |
Cell–cell interactions | Galectins, gliolectin, I-type lectins (e.g. siglecs, N-CAMu, P0 or L1), selectins and other C-type lectins such as DC-SIGN or macrophage mannose receptor |
Cell–matrix interactions | Calreticulin, discoidin I, galectins, heparin- and hyaluronic acid-binding lectins including hyalectans/lecticans |
Matrix network assembly | Galectins (e.g. galectin-3/hensin), non-integrin 67 kDa elastin/laminin-binding protein, proteoglycan core proteins (C-type CRD and G1 domain of hyalectans/lecticans) |