S-layer glycoproteins and flagellins: reporters of archaeal posttranslational modifications.
Many archaeal proteins undergo posttranslational modifications. S-layer proteins and flagellins have been used successfully to study a variety of these modifications, including N-linked glycosylation, signal peptide removal and lipid modification. Use of these well-characterized reporter proteins in the genetically tractable model organisms, Haloferax volcanii, Methanococcus voltae and Methanococcus maripaludis, has allowed dissection of the pathways and characterization of many of the enzymes responsible for these modifications. Such studies have identified archaeal-specific variations in signal peptidase activity not found in the other domains of life, as well as the enzymes responsible for assembly and biosynthesis of novel N-linked glycans. In vitro assays for some of these enzymes have already been developed. N-linked glycosylation is not essential for either Hfx. volcanii or the Methanococcus species, an observation that allowed researchers to analyze the role played by glycosylation in the function of both S-layers and flagellins, by generating mutants possessing these reporters with only partial attached glycans or lacking glycan altogether. In future studies, it will be possible to consider questions related to the heterogeneity associated with given modifications, such as differential or modulated glycosylation.
Jarrell
Ken F
KF
Department of Microbiology and Immunology, Queen's University, Kingston, ON, Canada. jarrellk@queensu.ca
Jones
Gareth M
GM
Kandiba
Lina
L
Nair
Divya B
DB
Eichler
Jerry
J
D019843:Archaeal Proteins / Q000737:chemistry* / Q000302:isolation & purification; D005408:Flagellin / Q000737:chemistry* / Q000302:isolation & purification; D019622:Haloferax volcanii / Q000235:genetics / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000737:chemistry* / Q000302:isolation & purification; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D053858:Metabolic Networks and Pathways / Q000235:genetics; D017017:Methanococcus / Q000235:genetics / Q000378:metabolism*; D011134:Polysaccharides / Q000737:chemistry / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D012697:Serine Endopeptidases / Q000235:genetics / Q000378:metabolism
D019843:Archaeal Proteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D011134:Polysaccharides; C055764:S-layer proteins; D005408:Flagellin; D012697:Serine Endopeptidases; C026515:type I signal peptidase