Related Experiment Video
Updated: Jul 18, 2026

Tracking Single Proteins in Lipid Bilayers Using Fluorescence Microscopy
Published on: December 12, 2025
Aquaporin-11 containing a divergent NPA motif has normal water channel activity
Kaya Yakata1, Yoko Hiroaki, Kenichi Ishibashi
1Department of Biophysics, Faculty of Science, Kyoto University, Oiwake, Kitashirakawa, Sakyo-ku Kyoto 606-8502, Japan.
Abstract:
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.
Related Concept Videos
Aquaporins
Reabsorption and Secretion in the DCT and Collecting Duct
The distal part of the DCT, along with the...
ATP Driven Pumps III: V-type Pumps
The peripheral or cytosolic V1 domain with eight subunits is involved in ATP hydrolysis. The integral or transmembrane V0 domain containing at least five subunits...
Primary Active Transport
Primary Active Transport
Non-gated Ion Channels
Compared to the gated ion channels, the non-gated channels, also known as leakage or passive channels, have no gating mechanism.

