Molecular mapping of the conductance activity linked to tAE1 expressed in Xenopus oocyte.
It was previously shown that expressed in Xenopus oocyte the trout (tAE1) and the mouse (mAE1) anion exchangers behave differently: both elicit anion exchange activity but only tAE1 induces a transport of organic solutes correlated with an anion conductance. In order to identify the structural domains involved in the induction of tAE1 channel activity, chimeras have been prepared between mouse and trout AE1. As some constructs were not expressed at the plasma membrane, skate exchanger (skAE1) was used instead of mouse exchanger to complete the structure-function analysis. The present paper shows that skAE1, highly similar to mAE1, does not induce a chloride conductance when expressed in Xenopus oocyte. Construct expression analysis showed that only tAE1 transmembrane domain is linked to the anion conductance. More precisely, we identified two regions composed of helices 6, 7 and 8 and putative helices 12 and 13 which are required for this function.
Borgese
Franck
F
Laboratoire de Physiologie des Membranes Cellulaires, FRE 2721, CNRS-Université de Nice, Bâtiment Jean Maetz, 284 chemin du Lazaret, 06230 Villefranche/Mer, France. borgese@obs-vlfr.fr
Renard
Céline
C
Gabillat
Nicole
N
Pellissier
Bernard
B
Guizouarn
Hélène
H
D000818:Animals; D001457:Anion Exchange Protein 1, Erythrocyte / Q000737:chemistry* / Q000235:genetics*; D001639:Bicarbonates / Q000737:chemistry; D015153:Blotting, Western; D002462:Cell Membrane / Q000378:metabolism; D018118:Chloride Channels / Q000737:chemistry; D004594:Electrophysiology / Q000379:methods*; D051379:Mice; D008954:Models, Biological; D009865:Oocytes / Q000378:metabolism*; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D018075:RNA, Complementary / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000737:chemistry; D013329:Structure-Activity Relationship; D014337:Trout; D014982:Xenopus laevis / Q000378:metabolism*
D001457:Anion Exchange Protein 1, Erythrocyte; D001639:Bicarbonates; D018118:Chloride Channels; D018075:RNA, Complementary; D011993:Recombinant Fusion Proteins