ZFIN ID: ZDB-PUB-101209-3
The NPC motif of aquaporin-11, unlike the NPA motif of known aquaporins, is essential for full expression of molecular function
Ikeda, M., Andoo, A., Shimono, M., Takamatsu, N., Taki, A., Muta, K., Matsushita, W., Uechi, T., Matsuzaki, T., Kenmochi, N., Takata, K., Sasaki, S., Ito, K., and Ishibashi, K.
Date: 2011
Source: The Journal of biological chemistry   286(5): 3342-3350 (Journal)
Registered Authors: Kenmochi, Naoya, Uechi, Tamayo
Keywords: Endoplasmic reticulum(ER), Kidney, Membrane proteins, Water channel, Zebra fish, aquaporin
MeSH Terms:
  • Amino Acid Motifs/genetics
  • Animals
  • Aquaporins/administration & dosage
  • Aquaporins/genetics*
  • Aquaporins/pharmacology
  • Aquaporins/physiology
  • CHO Cells
  • Cell Membrane Permeability
  • Cricetinae
  • Cricetulus
  • Dipeptides*
  • Humans
  • Mice
  • Mutation*
  • Transfection
  • Water/metabolism
  • Zebrafish
PubMed: 21118806 Full text @ J. Biol. Chem.
FIGURES
ABSTRACT
The recently identified molecule aquaporin-11 (AQP11) has a unique amino acid sequence pattern that includes an Asn-Pro-Cys (NPC) motif, corresponding to the N-terminal Asn-Pro-Ala (NPA) signature motif of conventional AQPs. In this study we examined the effect of the mutation of the NPC motif on the subcellular localization, oligomerization, and water permeability of AQP11 in transfected mammalian cells. Furthermore the effect was also assessed using zebrafish. Site-directed mutation at the NPC motif did not affect the subcellular localization of AQP11, but reduced its oligomerization. A cell swelling assay revealed that cells expressing AQP11 with a mutated NPC motif had significantly lower osmotic water permeability than cells expressing wild-type AQP11. Zebrafish deficient in endogenous AQP11 showed a deformity in the tail region at an early stage of development. This phenotype was dramatically rescued by injection of human wild-type AQP11 mRNA, whereas the effect of mRNA for AQP11 with a mutated NPC motif was less marked. Although the NPA motif is known to be important for formation of water-permeable pores by conventional AQPs, our observations suggest that the corresponding NPC motif of AQP11 is essential for full expression of molecular function.
ADDITIONAL INFORMATION