Notable Aspects of Glycan-Protein Interactions.
This mini review highlights several interesting aspects of glycan-mediated interactions that are common between cells, bacteria, and viruses. Glycans are ubiquitously found on all living cells, and in the extracellular milieu of multicellular organisms. They are known to mediate initial binding and recognition events of both immune cells and pathogens with their target cells or tissues. The host target tissues are hidden under a layer of secreted glycosylated decoy targets. In addition, pathogens can utilize and display host glycans to prevent identification as foreign by the host's immune system (molecular mimicry). Both the host and pathogens continually evolve. The host evolves to prevent infection and the pathogens evolve to evade host defenses. Many pathogens express both glycan-binding proteins and glycosidases. Interestingly, these proteins are often located at the tip of elongated protrusions in bacteria, or in the leading edge of the cell. Glycan-protein interactions have low affinity and, as a result, multivalent interactions are often required to achieve biologically relevant binding. These enable dynamic forms of adhesion mechanisms, reviewed here, and include rolling (cells), stick and roll (bacteria) or surfacing (viruses).
Depatment of Cellular and Molecular Medicine, University of California, San Diego, 9500 Gilman Drive, BRF2 MC 0687, La Jolla, CA 92093-0687, USA. micohen@ucsd.edu.
Miriam
M
Cohen
D000818:Animals; D001419:Bacteria / Q000472:pathogenicity; D018407:Bacterial Physiological Phenomena; D054884:Host-Pathogen Interactions; D006801:Humans; D011134:Polysaccharides / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism*; D018406:Virus Physiological Phenomena; D014780:Viruses / Q000472:pathogenicity
D011134:Polysaccharides; D011506:Proteins
FimH; cumulus oophorus; glycans; hyaluronan; influenza A; leukocytes; mucus; rolling adhesion; sialic acids; sperm; stick and roll; surfacing