title: Mannose-6-phosphate: a regulator of LLO destruction.
abstract: Oligosaccharyltransferase (OT) catalyzes the signature reaction of the asparagine-linked glycosylation pathway, namely, the transfer of preformed glycans from the lipid-linked oligosaccharide Glc3Man9GlcNAc2-P-P-Dolichol (G3M9Gn2-LLO) to appropriate asparaginyl residues on acceptor polypeptides. We have identified a reaction, possibly catalyzed by OT, that results in the hydrolysis or "transfer to water" of host LLOs in response to viral infection with release of a free G3M9Gn2 glycan. The loss of LLO ostensibly hinders N-glycosylation of viral polypeptides. This response is achieved by a novel stress-activated signaling pathway in which free mannose-6-phosphate (M6P) acts as a second-messenger. Here, we describe methods with permeabilized mammalian cells for activation of the M6P-regulated LLO hydrolysis, or transfer of glycan to water, in vitro.
authors.affiliation: Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas, USA.
authors.forename: Ningguo
authors.initials: N
authors.lastname: Gao
authors.forename: Mark A
authors.initials: MA
authors.lastname: Lehrman
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism; D018929:Cell Culture Techniques / Q000379:methods; D002463:Cell Membrane Permeability; D006031:Glycosylation; D006868:Hydrolysis; D008070:Lipopolysaccharides / Q000378:metabolism*; D008360:Mannosephosphates / Q000378:metabolism*; D011105:Polyisoprenyl Phosphate Sugars / Q000378:metabolism; D011134:Polysaccharides / Q000378:metabolism; D013301:Streptolysins / Q000378:metabolism; D014867:Water / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; C066723:Glc(3)Man(9)(GlcNAc)(2)-diphosphate-dolichol; D008070:Lipopolysaccharides; D008360:Mannosephosphates; D011105:Polyisoprenyl Phosphate Sugars; D011134:Polysaccharides; D013301:Streptolysins; C023023:lipid-linked oligosaccharides; C025964:streptolysin O; D014867:Water; C027693:mannose-6-phosphate