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Table 3 Functions of animal and human lectins a

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)

  1. aadapted from [42], with permission, and extended.
  2. bSkp-1-Cul1-F-box protein complex.
  3. cER degradation enhancing α-mannosidase-like protein.
  4. dmannose-6-phosphate receptor homology.
  5. eXTP3-transactivated gene B precursor.
  6. fosteosarcoma 9.
  7. gER-Golgi intermediate compartment protein (lectin) (MW: 53 kDa).
  8. hvesicular-integral (membrane) protein (lectin) (MW: 36 kDa).
  9. iERGIC-53-like protein.
  10. jVIP-36-like protein.
  11. kcarbohydrate recognition domain.
  12. ldendritic cell-specific ICAM-3-grabbing nonintegrin.
  13. mhyaluronan receptor for endocytosis.
  14. nlipooligosaccharide.
  15. olipopolysaccharide.
  16. pcomplement receptor type 3.
  17. qmember of regenerating (reg) gene family of secreted proteins.
  18. rUDP-GalNAc:polypeptide N-acetylgalactosaminyltransferases.
  19. sinterleukin-2.
  20. treceptor for hyaluronan-mediated motility.
  21. uneural cell adhesion molecule.