The role of N ‐glycosylation in transport function and surface targeting of the human solute carrier PAT1
2009; Wiley; Volume: 583; Issue: 10 Linguagem: Inglês
10.1016/j.febslet.2009.04.037
ISSN1873-3468
AutoresMadlen Dorn, Michael Jaehme, Matthias Weiwad, F Markwárdt, Rainer Rudolph, Matthias Brandsch, Eva Bosse-Doenecke,
Tópico(s)Adenosine and Purinergic Signaling
ResumoIn the present study we show in the Xenopus laevis expression system that the proton‐coupled amino acid transporter 1 (PAT1, SLC36A1) is glycosylated at asparagine residues N174, N183 and N470. To determine the functional role of N ‐glycosylation, glycosylation‐deficient mutants were analyzed by two‐electrode voltage‐clamp measurements after expression in X. laevis oocytes. Single replacements of asparagine residues had no effect on transport activity. However, multiple substitutions resulted in a decreased transport rate, leaving K t unchanged. Immunofluorescence localisation revealed a diminished plasma membrane expression of glycosylation‐defective mutants. This indicates that N ‐glycans are not required for transport function, but are important for membrane targeting.
Referência(s)