Aquaporin-11 containing a divergent NPA motif has normal water channel activity.
Recently, two novel mammalian aquaporins (AQPs), AQPs 11 and 12, have been identified and classified as members of a new AQP subfamily, the "subcellular AQPs". In members of this subfamily one of the two asparagine-proline-alanine (NPA) motifs, which play a crucial role in selective water conduction, are not completely conserved. Mouse AQP11 (mAQP11) was expressed in Sf9 cells and purified using the detergent Fos-choline 10. The protein was reconstituted into liposomes, which were used for water conduction studies with a stopped-flow device. Single water permeability (pf) of AQP11 was measured to be 1.72+/-0.03x10(-13) cm(3)/s, suggesting that other members of the subfamily with incompletely conserved NPA motifs may also function as water channels.
Yakata
Kaya
K
Department of Biophysics, Faculty of Science, Kyoto University, Oiwake, Kitashirakawa, Sakyo-ku Kyoto 606-8502, Japan.
Hiroaki
Yoko
Y
Ishibashi
Kenichi
K
Sohara
Eisei
E
Sasaki
Sei
S
Mitsuoka
Kaoru
K
Fujiyoshi
Yoshinori
Y
D000409:Alanine / Q000235:genetics*; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D020346:Aquaporins / Q000032:analysis / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D001216:Asparagine / Q000235:genetics*; D016367:Baculoviridae / Q000235:genetics; D002478:Cells, Cultured; D008081:Liposomes / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D011392:Proline / Q000235:genetics*; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D018411:Spodoptera / Q000166:cytology / Q000378:metabolism; D014162:Transfection; D014867:Water / Q000378:metabolism*
D020346:Aquaporins; D008081:Liposomes; D011994:Recombinant Proteins; D014867:Water; D001216:Asparagine; D011392:Proline; D000409:Alanine