Identification and characterization of a new cationic amino acid transporter named PQ-Loop-Containing protein 2 (PQLC2)
Résumé
Cystinosin, the lysosomal cystine exporter defective in cystinosis, is the founding member of a 7-TM membrane protein family related to bacteriorhodopsin and characterized by a duplicated motif termed PQ loop. The molecular function of the other PQ-loop proteins remains unknown.
Recently, we used proteomics, yeast genetic and transport studies to characterize PQLC2, a new lysosomal cationic amino acid (CAA) transporter (Jezegou et al., PNAS 2012). Here, we present some aspects of this work and give new elements concerning its biophysical mechanism.
This study also brings new insights concerning the molecular mechanism by which cysteamine acts in cystinosis treatment. It shows also that PQLC2, despite its pH sensitivity, is not coupled to proton transport. This feature support that PQLC2 activity is very sensitive to lysosomal voltage.
Domaines
Sciences du Vivant [q-bio]| Origine | Fichiers produits par l'(les) auteur(s) |
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