ESSENTIALS OF GLYCOBIOLOGY

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ESSENTIALS OF GLYCOBIOLOGY LECTURE 22 MAY 7,
2002 Richard D. Cummings, Ph.D. University of
Oklahoma Health Sciences Center College of
Medicine Oklahoma Center for Medical
Glycobiology THE C-TYPE LECTINS
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Prototype C-type lectin Asialoglycoprotein
receptor

• Ashwell and Morell 1960s and 1970s
• Rapid clearance of desialylated, radioactive
  glycoprotein after injection into circulation
• Removal of galactose prolonged serum lifetime
• Radioactive glycoproteins sequestered in liver
• Ca2-dependent receptor purified from rabbit
  liver membranes
• Two subunits, trimeric structure
• Other related proteins purified trimeric
  structures with sequence similarities

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Conserved Carbohydrate-Recognition Domain of
C-type Lectins
Rat Mannose Binding Protein C
-ENWGAGEPNNKKSKEDCVEIYIKRERDSGKWNDDACHKRKAALCY-
-TNWNEGEPNNVGSGENCVVLLT-----NGKWNDVPCSDSFLVVCE-
Mouse L-selectin
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Variations in Structures of C-type Lectins
Proteoglycans
Endocytic Receptors
Selectins
Collectins
N
OUT
N
N
Plasma Membrane
N
N
N
N
N
Lectin Domain
C
IN
Complement Regulatory Repeat (Consensus Repeat)
EGF-Like Domain
Fibronectin Type II Repeat
a
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Variations in Structures of C-type Lectins
Bouquet
Examples Mannose-binding protein A
Surfactant SP-A
Cruciform
Examples Conglutinin Surfactant SP-D
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Types of C-type Lectins

• Endocytic receptors
• rat kupffer cell receptor
• human macrophage mannose receptor
• rat asialoglycoprotein receptor R2/3 (hepatic
  lectin 2/3)
• human asialoglycoprotein receptor (hepatic lectin
  H1)
• chicken hepatic lectin
• dendritic cell and thymic epithelial cells
  DEC-205
• (homolog of macrophage mannose receptor)
• murine macrophage asialoglycoprotein-binding
  protein
• (macrophage Gal/GalNAc-specific
  lectin - MMGL)
• bovine 180 kD secretory phospholipase A2 receptor
• DEC 205 receptor
• Minkle (macrophage lectin inducible by TNF, IL-6
  and INF-?)
• DC-SIGN(R) appears to mediate interaction of T
  cells with dendritic cells via recognition of
  mannose containing glycans on ICAM-3Geijtenbeek
  et al, 2000.

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Types of C-type Lectins

• Collectins (collagen-like sequences function in
  innate immunity fix complement and have opsonin
  activity)
• bovine collectin-43
• bovine conglutinin
• rat mannose-binding protein A and C
• human mannose-binding protein
• human pulmonary surfactant-associated protein A
  (SP-A)
• human pulmonary surfactant-associated protein D
  (SP-D)
• human tetranectin (TN) (Plasminogen-kringle 4
  binding
• protein)

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Types of C-type Lectins

• Selectins
• L-selectin
• E-selectin
• P-selectin
• Lymphocyte lectins
• NK receptors (required for MHC-1 recognition)
• (the CTLD functions in protein-protein
  interaction)
• Ly49A through W
• NKR-P1
• CD94/NKG2A/B, -C or -E
• NKG2D
• CD69
• human mast cell function associated antigen
  (MCFA)
• activation-induced C-type lectin (AICL)
• human eosinophil granule major basic protein
• human low affinity immunoglobulin epsilon Fc
  receptor (CD23)
• P47 or LSLCL (lymphocytic secreted long form of
  C-type lectin)
• CIRE (expressed by splenic dendritic cells)

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Types of C-type Lectins
Proteoglycans human versican core protein (large
fibroblasts proteoglycan - CS proteoglycan
core protein-2 - glial hyaluronate binding
protein) human aggregan core protein
(cartilage-specific proteoglycan core protein -
CSPCP- CS proteoglycan core protein-1) rat
brevican core protein (brain-enriched HA
binding protein) rat neurocan core protein (245
kD early post-natalcore glycoprotein)
Others human integral membrane protein
DGCR2/IDD human lithostathine 1 aprecursor
(pancreatic stone protein - PSP) human
polycystin human endothelial cell scavenger
receptor human pancreatitis-associated protein 1
(PAP or HIP) human pancreatic beta cell growth
factor (INGAP)
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Types of C-type Lectins
Invetebrate Lectins Limulus clotting factor
(hemolymph of horseshoe crabTachypleus
tridentatus) Lectin BRA-2 (coelomic fluid of
acorn barnacle Megabalanus rosa) Newt Lectin
(oviduct of iberian ribbed newt Pleurodeles
waltii) Inducible Flesh fly lectin (Sarcophaga
peregrina) Tunicate lectin (Polyandrocarpa
misakiensis) Integral Spicule matrix lectin in
sea urchin (Strongylocentrotus purpuratus)
Sea urchin Echinoidin (Anthocidaris crassispina)
Cockroach lectin (hemolymph of Periplaneta
americana) Antifreeze protein (AFP) from the
sea raven (Hemitripterus americanus) Viral
Lectins Hepatic lectin homolog in Fowlpox
virus gp22-24 in Vaccinia virus
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Types of C-type Lectins
Snakes and Venoms Alboaggregin A subunit 1
(white-lipped pit viper Trimeresurus
albolabris) Phospholipase A2 inhibitor subunit
B (Trimeresurus flavoviridis) Echicetin alpha
subunit (saw-scaled viper Echis carinatus)
Coagulation factor IX/factor X-binding protein A
(IX/X-BP) (Trimeresurus flavoviridis)
Galactose-specific lectin (Crotalus atrox)
Botrocetin, alpha chain (platelet coagglutinin)
(Bothrops jararaca)
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Crystal structure of a trimeric rat
mannose-binding protein A (MBP-A) complexed with
mannose at 1.8 Å resolution. Mannose is
indicated in the stick figure and Ca2 and Cl are
indicated by the green and blue balls,
respectively. Note that Ca2 is closely
coordinated with the bound sugar.
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Ca2-Coordination by C-type Lectins
Left Structure of the CRD of DC-SIGN bound to
GlcNAc2Man3 Right Rat serum mannose-binding
protein bound to a high-mannose oligosaccharide
(From Feinberg et al, 2001)
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Ca2-Coordination by C-type Lectins
Interaction of the 1-3-linked branch with
DC-SIGNR. For clarity, the remaining sugar
residues are shown schematically. Ca2
coordination bonds are shown as solid black
lines hydrogen bonds, as dashed lines. Large
cyan sphere is Ca2 red, oxygen blue, nitrogen
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Ca2-Coordination by C-type Lectins
Interactions of the 1-3-linked branch with
DC-SIGN. The terminal GlcNAc1 forms a cross-link
by forming the typical C-type lectin interactions
with the principal Ca2 site of another CRD. For
clarity, only the coordination bonds to the Ca2
(gray) are shown
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Convergent Evolusion of C-type Lectin Domains
(CTLDs)
C-type lectin-like domains (CTLDs) of higher
eukaryotes are protein modules originally
identified as carbohydrate-recognition domains
(CRDs) in a family of Ca2-dependent animal
lectins. Less closely related but still
definitely homologous CTLDs have been identified
in a variety of proteins that do not appear to
have carbohydrate-binding activity. All of the
domains in the CTLD group show distinct evidence
of sequence similarity and are thus believed to
have descended from a common ancestor by a
process of divergent evolution. (from Drickamer,
K and Dodd, RB (1999) Glycobiology, 9, 1357-1369.
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Types of C-type Lectins
(From Dodd RB, Drickamer K. (2001) Lectin-like
proteins in model organisms implications for
evolution of carbohydrate-binding activity.
Glycobiology 11(5)71R-9R)
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Classification of C-type Lectins and Proteins
with C-type Lectin Domains (CTLDs)
Sushi Domain
I - Proteoglycans Aggrecan (major component of
extracellular matrix of cartilagenous tissues. a
major function of this protein is to resist
compression in cartilage. it binds avidly to HA
via an amino-terminal globular region.) Versican N
eurocan Brevican
EGF Domain
GAG Domain
Link Region
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Classification of C-type Lectins and Proteins
with C-type Lectin Domains (CTLDs)
II - Type 2 receptor IgE FcR (CD23) Asialoglycop
rotein Receptor Subunit 1 Asialoglycoprotein
Receptor Subunit 2 Macrophage Asialoglycoprotein
Receptor Kupffer cell receptor DC
immunoreceptor Scavenger receptor with
CTLD Mincle Langerin DC-SIGN DC-SIGNR Blood
Dendritic Cell Antigen 2 (BDCA-2)
Dendritic Lectin CLECSF11
HECL (CLECSF7) C-type
lectin-like receptor CLEC-6
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Classification of C-type Lectins and Proteins
with C-type Lectin Domains (CTLDs)
III - Collectins Mannose-binding protein
C Pulmonary Surfactant SP-A Mannose-binding
protein A Pulmonary Surfactant
SP-D Collectin-K1 Collectin-L1
IV - Selectins L-selectin E-Selectin P-selectin
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Classification of C-type Lectins and Proteins
with C-type Lectin Domains (CTLDs)
V - NK receptors Dectin-1 Mast cell
function-associated antigen HNKR-P1A LLT1 CD69
CD69 homolog CD72 CD94 KLRF1 Oxidised LDL
receptor CLEC-1 and -2 NKG2 A, C, D, E,
H Myeloid DAP12-associating lectin (MDL-1)
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Classification of C-type Lectins and Proteins
with C-type Lectin Domains (CTLDs)
VI - MMR family Mannose Receptor Endo180 Phosph
olipase-A2 receptor DEC205 (GP200-MR6)
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Classification of C-type Lectins and Proteins
with C-type Lectin Domains (CTLDs)
VII Free CTLDs Lithostathine/Reg
1alpha Lithostathine/Reg 1beta Pancreatitis-asso
ciated protein/HIP Pancreatic beta cell Growth
Factor Regenerating gene type IV
VIII Simple Type 1
receptors Layilin Layilin homolog
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Classification of C-type Lectins and Proteins
with C-type Lectin Domains (CTLDs)

• IX - Tetranectin
• Tetranectin (plasminogen-binding protein)
• Cartilage-derived CTL
• Stem cell growth factor
• X - Polycystin
• Polycystin

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Classification of C-type Lectins and Proteins
with C-type Lectin Domains (CTLDs)

• XI - Attractin
• Attractin (rapidly and transiently expressed on
  the activated T lymphocyte that aids in the
  formation of clusters with monocytes
  macrophages)
• Attractin homolog
• XII - CTLD acidic neck
• KIAA0022 protein
• Eosinophil Major Basic Protein (predominant
  constituent of
• the crystalline core of the eosinophil
  primary granule)
• Eosinophil Major Basic Protein homolog

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Classification of C-type Lectins and Proteins
with C-type Lectin Domains (CTLDs)

• XIII - IDD (DGCR2 DiGeorge syndrome critical
  region gene 2)
• IDD (may play a role in so-called Catch22
  syndromes resulting from deletions on
  Chromosome 22)
• XIV - Endosialin
• Endosialin

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A
B
Structure of the CRD-4 of the macrophage mannose
receptor (A) and comparison to the CRD-A of the
rat mannose-binding protein (MBP-A) (B).
Disulfide bonds are shown in pink ball-and-stick
representation, and the Ca2 is shown as a
blue-green sphere. The two segments that connect
the extended loop to the core of the CRD, region
I (residues 701-708) and region II (residues
729-734), are shown in yellow. For the MBP-A CRD,
Ca2 site 1 is the auxiliary site, and Ca2 site
2 is the principal site.
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Structures of CRDs in C-type Lectins
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Recognition of Glycosulfopeptides By P-selectin
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Similarities in C-type Lectin Domain Structure
E-Selectin
P-Selectin
MBP-C
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Ly49A
Ly49I
Anatomy of C-type lectin-like domains of NK
receptors. Ribbon diagrams of Ly49A, Ly49I
(1JA3), NKG2D (1HQ8), CD69 (1FM5), CD94 (1B6E),
and MBP-A. The secondary structural elements
are colored as follows b-strands blue, -helices
red, and loop regions gold. The disulphide bonds
are shown in green as ball-and-stick
representation. The Ca2 ions bound to MBP-A are
drawn as magenta spheres.
NKG2D
CD69
MBP-A
CD94
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Recognition of MHC-I by the Ly49A, KIR2DL and
NKG2D NK cell receptors. The KIR2DL2/HLA-Cw3 and
NKG2D/MICA complexes (50, 58) were superimposed
onto the Ly49A/H-2Dd complex using equivalent C
atoms of the 1 and 2 domains of the MHC-I
molecules. For clarity, the only MHC-I molecule
shown is H-2Dd. The H-2Dd heavy chain is gold,
the peptide is blue, and ß2m is gray. The Ly49A
monomers interacting at Site 2 are cyan and light
blue, KIR2DL is magenta, and the NKG2D monomers
are green and pink. The overlapping area of
KIR2DL and NKG2D is transparent.
From Natarajan K, Dimasi N, Wang J, Mariuzza
RA, Margulies DH. (2002)STRUCTURE AND FUNCTION OF
NATURAL KILLER CELL RECEPTORS Multiple Molecular
Solutions to Self, Nonself Discrimination. Annu
Rev Immunol 20853-85