Description
Cation-independent electroneutral transporter (not associated with membrane depolarization) of a variety of tricarboxylic and dicarboxylic acid-cycle intermediates. There is also small, but detectable, transport of monocarboxylics. Transport is through the epithelium of the gut and across the plasma membranes of organs involved in intermediary metabolism and storage. Affinity for substrates is citrate > succinate > pyruvate. Fumarate, a-ketoglutarate, and glutarate are also transported, but not lactate. Transport mechanism that is not coupled to Na(+), K(+), or Cl(-). Function is shown in Xenopus oocytes and human retinal pigment epithelial (HRPE) cell lines.
Subunit of the oligosaccharyl transferase (OST) complex that catalyzes the initial transfer of a defined glycan (Glc(3)Man(9)GlcNAc(2) in eukaryotes) from the lipid carrier dolichol-pyrophosphate to an asparagine residue within an Asn-X-Ser/Thr consensus motif in nascent polypeptide chains, the first step in protein N-glycosylation. N-glycosylation occurs cotranslationally and the complex associates with the Sec61 complex at the channel-forming translocon complex that mediates protein translocation across the endoplasmic reticulum (ER).