Membrane topology of system xc-light subunit reveals a re-entrant loop with substrate-restricted accessibility
E Gasol, M Jiménez-Vidal, J Chillarón… - Journal of Biological …, 2004 - ASBMB
Heteromeric amino acid transporters are composed of a heavy and a light subunit linked by
a disulfide bridge. 4F2hc/xCT elicits sodium-independent exchange of anionic l-cysteine
and l-glutamate (system xc−). Based on the accessibility of single cysteines to 3-(N-
maleimidylpropionyl) biocytin, we propose a topological model for xCT of 12 transmembrane
domains with the N and C termini located inside the cell. This location of N and C termini
was confirmed by immunofluorescence. Studies of biotinylation and accessibility to …
a disulfide bridge. 4F2hc/xCT elicits sodium-independent exchange of anionic l-cysteine
and l-glutamate (system xc−). Based on the accessibility of single cysteines to 3-(N-
maleimidylpropionyl) biocytin, we propose a topological model for xCT of 12 transmembrane
domains with the N and C termini located inside the cell. This location of N and C termini
was confirmed by immunofluorescence. Studies of biotinylation and accessibility to …
