Figure 2.

N-glycans occupy the atypical motif Asn¹⁷-X-Cys¹⁹ of hGPR109A. A) The amino acid sequence of hGPR109A was obtained from the UniprotKB/Swiss-Prot database (ID: Q8TDS4). Putative transmembrane domains are boxed and 6 Asn residues within the extracellular regions are shown in bold. B) hGPR109A/WT and Ala substitution mutations (1 of 6 extracellular Asn residues) were each transiently expressed in HeLa cells, and the molecular mass of each product was determined using SDS-PAGE and Western blot analyses. C) hGPR109A/WT and Ala substitution mutants (amino acids proximal to Asn¹⁷) were each transiently expressed in HeLa cells and the molecular mass of each product was determined using SDS-PAGE and Western blot analyses, as described in the Materials and Methods. The positions of molecular markers are indicated on the right, and the approximate molecular sizes are shown on the left. Data are representative of 3 independent experiments that yielded similar results.