English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Pig liver oligosaccharyltransferase (OST) is aheterooligomeric protein complex responsible for the cotranslational transferof GlcNAc[2]Man[9]Glc[3] from Dol PP onto specific asparagine residues in thenascent polypeptide. OST48, one of the catalytic subunits in this complex,exerts a typical type I membrane topology, containing a large luminal domain, ahydrophobic transmembrane domain and a short cytosolic peptide tail. BecauseOST48 is found within the endoplasmic reticulum (ER) when overexpressed inCOS-1 cells, we carried out experiments to identify structural signalspotentially capable of directing ERtargeting, using OST48 mutants and hybridproteins consisting of individual OST48 domains and Man[9] mannosidase.Immunofluorescence microscopy showed that OST48 mutants in which the Cterminallysine-3 or lysine-5, but not lysine-7, had been replaced by leucine (OST48?K)could be detected on the cell surface. This indicates that these two lysineresidues are sufficient for conferring ERresidency on OST48. The doublelysinemotif operates only when exposed cytosolically, where it acts as a relocationsignal rather than causing retention. OST48?K-3, when coexpressed in COS-1cells together with myctagged ribophorin I, was quantitatively retained in theER. By contrast, coexpression in the presence of ribophorin I resulted in noreduction of cell surface fluorescence for the OMO?K-5 chimera containing thecytosolic and transmembrane domain of OST48 attached to the Cterminus of theMan[9]mannosidase luminal domain. Thus ERlocalisation of OST48 is probablybrought about by complex formation with ribophorin I and this most likelyinvolves the luminal domains of both proteins. Consequently, the doublelysinemotif in the cytosolic domain of OST48 is unlikely to have a primary functionexcept being involved in recapture of molecules which have escaped from theER.

Analysis of Structural Signals Conferring Localisation of Pig OST48 to the Endoplasmic Reticulum