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Vsetko je Glykobiologia A co to vlastne je?

Vsetko je Glykobiologia A co to vlastne je?. Lubor Borsig Univerzita Zürich Bratislava, Maj 2008. „CURRENT“. Co je glykobiologia?. „OLD“. Linkage variability of monosaccharides. Three nucleotide bases or amino acids can only generate 6 variations.

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Vsetko je Glykobiologia A co to vlastne je?

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  1. Vsetko je GlykobiologiaA co to vlastne je? Lubor Borsig Univerzita Zürich Bratislava, Maj 2008

  2. „CURRENT“ Co je glykobiologia? „OLD“

  3. Linkage variability of monosaccharides Three nucleotide bases or amino acids can only generate 6 variations Three hexoses can generate from 1‘056 to 27‘648 unique structures

  4. [Glc(b1-4)Glc] [Glc(a1-4)Glc] n n Biological relevance of oligosaccharide linkages

  5. Definition of Glycosylation Classes O-(Xyl) linked oligosaccharide Glycosaminoglycan N-(GlcNAc) linked oligosaccharide N-glycan Glycophospholipid anchor GPI anchor O-(GalNAc) linked oligosaccharide O-glycan Ceramide-linked oligosaccharides Glycolipids O-linked (GlcNAc) O-GlcNAc Varki A. et al Essentials in Glycobiology 1999

  6. AsN AsN AsN dolichol GlcNAc Man Glc N-linked protein glycosylation Golgi Endoplasmic Reticulum Cytoplasm Lumen

  7. N-linked glycosylation in the ER

  8. U D P G U D P - C T P C D P P PP UDP M M M M M M M M M M M M M M M M M M M M M G D M M M M M M M M M M M M M M M Fru-6-P Man-6-P N-linked glycosylation:the human pathway PMM2 PMI Man-1-P PSA1 Cytoplasm UMP UDP G DP - M G D P G M DPM1/2/3 SEC59 ALG5 Lec35/MPDU1 P P P P P UDP P CWH8 GPT G M P ALG1 Lumen M STT3 RIB1 WBP1 OST3 RIB2 DAD1 OST5 OST4 G G ALG2 G G G G G G G M G G M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M ALG11 M M M M M M M M G D P RFT1 ALG3 ALG9 ALG12 ALG9 ALG6 ALG8 ALG10 = G glucose = M mannose = dolichol = GlcNAc

  9. Congenital disorders of glycosylation(CDG) • clinical symptomes: • developmental delay • psychomotor retardation, mental deficiency, • often epilepsy • variable dysmorphic features • 20% mortality, occurring nearly exclusively • before the age of 6 years

  10. - - - - N N N N Hypoglycosylation of serum transferrin in CDG type I patient - - - N N CDGS type II CDG type Ia CDG type Ic - - normal + 4 3 N N 2 0 - CDG type II (defect after OTase) CDG type I (defect before OTase)

  11. Golgi glycosylation • Glycoproteins trafficking • Glycosyltransferase localization • Nucleotide sugar synthesis and transporters

  12. Golgi organization Pictures and movie from J. Rohrer & B. Schaub

  13. Golgi organization Vesicles and stacks Difference vertebrate vs insects Golgi Structure in Three Dimensions: Functional Insights from the Normal Rat Kidney Cell Mark S. Ladinsky M et al., J.Cell Biol. (1999) 144, 1135-1149

  14. Golgi dynamics

  15. Topology of glycosyltransferases • Localization and trafficking signals • Regulatory function (phosphorylation) • Donor and acceptor substrate binding • Regulatory elements ? Catalytic domain Lumen Stem region Membrane Transmembrane domain Cytosol N C

  16. N-linked glycosylation pathway

  17. Golgi stack Glycosyltransferase reaction NDP + Acceptor-sugar NDP-sugar + Acceptor NMP NDP-sugar NMP NDP-sugar Acceptor Pi NDP Acceptor-sugar

  18. Man Man Man Man Man Man Man Man Man Man Man Man Man Man GlcNAc GlcNAc N N N-glycan maturation: trimming Man Man GlcNAc Man Man Man GlcNAc Man Man Man GlcNAc GlcNAc GlcNAc Mannosidase-IIa Mannosidase-IIx GnT1 Mannosidase-I GlcNAc GlcNAc GlcNAc N N

  19. GalNAc Man Man Man Man GlcNAc GlcNAc GlcNAc GlcNAc GlcNAc GlcNAc GlcNAc Gal Gal Gal Gal B3GALT B4GALT ST3GAL ST6GAL FUT B4GALNT N N Fuc Fuc N-glycan maturation: elongation Sia Man Man Man Man Man Man Man Man GlcNAc GlcNAc GlcNAc GlcNAc GnT2 GlcNAc GlcNAc GlcNAc GlcNAc N N

  20. GnT3 GnT4 GnT2 GnT5 GnT1 Man b4 b4 b2 b6 b2 N-glycan maturation: branching GlcNAc GlcNAc GlcNAc GlcNAc GlcNAc a6 a3 Man GlcNAc Man GlcNAc N

  21. Typical N-glycan chains Sia GlcNAc Gal Sia GlcNAc Sia Gal Gal GlcNAc Fuc GlcNAc Gal Gal GlcNAc Gal GalNAc GalNAc GlcNAc GlcNAc Sia Gal Gal Fuc Fuc GlcNAc Gal Gal Gal GlcNAc GlcNAc Gal S GlcNAc Sialylated LacNAc SialylatedLacto-N-biose Sialyl-LewisX Sulfo-4-GalNAc Blood group A Blood group B Gallili epitope Poly-LacNAc

  22. Sia Sia Sia Sia Gal Gal Gal Gal Branching defects DGnT2: peri-natal lethality (CDG-IIa) DGnT4: type 2 diabetes GlcNAc GlcNAc GlcNAc Man GlcNAc DGnT5: T-cell hyperreactivity, endocytosis of membrane receptors Man DGnT1: embryonic lethality Man GlcNAc GlcNAc N

  23. Biology of Glycans Glycans during evolution

  24. Gal Gal Gal Loss of a1-3 GalT in Old-World primates GlcNAc GlcNAc a1-3 GalT R R

  25. „Exposed“ Sialic acid Varki A. Nature 446: 1023 (2007)

  26. What is Ac and Gc Sialic Acid? Sialic acid comes in more than 40 modifications Neu5Ac (human) Neu5Gc (nonhuman) CMP-Neu5Ac hydroxylase

  27. Sialic Acid binding Lectins

  28. The Red Queen effect "Well, in our country," said Alice, still panting a little, "you'd generally get to somewhere else — if you run very fast for a long time, as we've been doing.„ "A slow sort of country!" said the Queen. "Now, here, you see, it takes all the running you can do, to keep in the same place. If you want to get somewhere else, you must run at least twice as fast as that!" Lewis Carroll, Through the Looking-Glass

  29. Host-pathogen interactions drives glycan evolution Host glycans mediate intrinsic functions and pathogen binding Host glycans as decoys to divert pathogens Pathogens evolve to bind to host glycans Pathogens evolve to avoid host decoy glycans RED QUEEN EFFECT RED QUEEN EFFECT Host with altered Glycans survives RED QUEEN EFFECT Pathogens evolve molecular mimics of host glycans Host recognizes pathogen glycans as „non-self“ Varki A. Cell 126: 841 (2006)

  30. Influenza epidemics

  31. a2-6Sia vs. a2-3Sia specificity a2-6Sia a2-3Sia Arg139 Gly139 Lys182 Asn182 Arg192 Gln192 Yamada et al. (2006) Nature444, 378-382

  32. Neuraminidase inhibition

  33. Glycosaminoglycans

  34. Synthesis of glycosaminoglycans Bishop JR et al, Nature 446:1030 (2007)

  35. Many roles of heparan sulphate proteoglycans in cell physiology Bishop JR et al, Nature 446:1030 (2007)

  36. Proteoglycans and Glycosaminoglycans • Heparan sulfate • Chondroitin sulfate • Dermatan sulfate • Hyaluronan • Keratan sulfate • Diseases of GAG biosynthesis

  37. Glycosaminoglycan (GAG) chains Chondroitin sulfate Gal NAc Gal Dermatan sulfate NAc S GlcA S Glc S S Gal GlcA NAc S NAc Gal Heparan sulfate NAc GlcA GlcA S S Gal IdoA Glc S S NAc Gal NAc S NAc GlcA S IdoA S S IdoA Gal NAc Gal Glc NAc NAc GlcA GlcA GlcA Gal Gal Gal Gal Gal Gal GlcA Xyl Xyl Xyl Gal Gal a4GlcNAcT b4GalNAcT Xyl Gal Gal Gal Xyl Xyl Xyl Ser Ser Ser Ser

  38. GlcA GlcA GlcA GlcA GlcA GlcA GlcA GlcNAc GlcNAc GlcNAc GlcNAc GlcNAc GlcNAc GlcNAc UDP- UDP- Hyaluronan [GlcNAc(b1-3)GlcA(b1-4)]n outside inside HAS in bacteria (Streptococcus, Pasteurella), vertebrates and even viruses (Paramecium bursaria Chlorella virus)

  39. Heparan sulfate proteoglycans

  40. Proteoglycans

  41. Proteoglycan Aggrecan Hyaluronic acid Core protein Glycosaminoglycans Protein-Ser-Xyl-Gal-Gal-GlcUS-[Disaccharid]n Non-covalent association

  42. S S S S S S S S S S S S S S S S S S P P Local growth factors BMP4 FGF2 FGF2 FGF2 Proteoglycan FGF2- Receptor

  43. Hereditary Multiple Exostoses EXT and EXTL mutations Cartillage tumors close to the ends of long bones (osteochondromas, exostoses)

  44. Defects in GAG synthesis FGF2 00 FGF18 BMPs Normal Exostoses

  45. Glycolipids

  46. Gal Gal Glc Cer Gal Gal Gal Gal GalNAc GalNAc Gal Glc Glc Glc Glc Sia Gal Cer Cer Cer Cer Cer GlcNAc Glycolipid classes Globosides Lactosides Gangliosides GM1

  47. Glycolipids and lipid rafts Degroote et al., Seminars in Cell & Developmental Biology, 15, 375-87, 2004

  48. Glycolipids in signalling GM1 in signalling: closely associated with neurotrophic tyrosine kinase receptor EGF

  49. The ABO-System: ABO blood group system

  50. Man GlcNAc GlcNAc Gal Gal Fuc Analysis of glycans • Protein backbone sequence • Glycosidic Linkages • Branching points • Monosaccharide composition • Modifications (e.g. sulfation) Sia Man Man GlcNAc S Sia Gal GlcNAc Sia GalNAc -GDSVCTNQSRLFQLKSPTTQNFDAS- GalNAc

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