title: N-glycosylation in Haloferax volcanii: adjusting the sweetness.
abstract: Long believed to be restricted to Eukarya, it is now known that cells of all three domains of life perform N-glycosylation, the covalent attachment of glycans to select target protein asparagine residues. Still, it is only in the last decade that pathways of N-glycosylation in Archaea have been delineated. In the haloarchaeon Haloferax volcanii, a series of Agl (archaeal glycosylation) proteins is responsible for the addition of an N-linked pentasaccharide to modified proteins, including the surface (S)-layer glycoprotein, the sole component of the surface layer surrounding the cell. The S-layer glycoprotein N-linked glycosylation profile changes, however, as a function of surrounding salinity. Upon growth at different salt concentrations, the S-layer glycoprotein is either decorated by the N-linked pentasaccharide introduced above or by both this pentasaccharide as well as a tetrasaccharide of distinct composition. Recent efforts have identified Agl5-Agl15 as components of a second Hfx. volcanii N-glycosylation pathway responsible for generating the tetrasaccharide attached to S-layer glycoprotein when growth occurs in 1.75 M but not 3.4 M NaCl-containing medium.
authors.affiliation: Department of Life Sciences, Ben Gurion University of the Negev Beersheva, Israel.
authors.forename: Jerry
authors.initials: J
authors.lastname: Eichler
authors.affiliation: Department of Life Sciences, Ben Gurion University of the Negev Beersheva, Israel.
authors.forename: Adi
authors.initials: A
authors.lastname: Arbiv
authors.affiliation: Department of Life Sciences, Ben Gurion University of the Negev Beersheva, Israel.
authors.forename: Chen
authors.initials: C
authors.lastname: Cohen-Rosenzweig
authors.affiliation: Department of Life Sciences, Ben Gurion University of the Negev Beersheva, Israel.
authors.forename: Lina
authors.initials: L
authors.lastname: Kaminski
authors.affiliation: Department of Life Sciences, Ben Gurion University of the Negev Beersheva, Israel.
authors.forename: Lina
authors.initials: L
authors.lastname: Kandiba
authors.affiliation: Department of Life Sciences, Ben Gurion University of the Negev Beersheva, Israel.
authors.forename: Zvia
authors.initials: Z
authors.lastname: Konrad
keywords: Archaea; Haloferax volcanii; N-glycosylation; S-layer glycoprotein; post-translational modification; protein glycosylation