PMID- 10564231
OWN - NLM
STAT- MEDLINE
DCOM- 19991220
LR  - 20180921
IS  - 0002-9513 (Print)
IS  - 0002-9513 (Linking)
VI  - 277
IP  - 5
DP  - 1999 Nov
TI  - Functional and molecular characterization of the human neutral solute channel
      aquaporin-9.
PG  - F685-96
LID - 10.1152/ajprenal.1999.277.5.F685 [doi]
AB  - In metabolically active cells, the coordinated transport of water and solutes is 
      important for maintaining osmotic homeostasis. We recently identified a broad
      selective-neutral solute channel, AQP9, from rat liver that allows the passage of
      a wide variety of water and neutral solutes (H. Tsukaguchi, C. Shayakul, U. V.
      Berger, B. Mackenzie, S. Devidas, W. B. Guggino, A. N. van Hoek, and M. A.
      Hediger. J. Biol. Chem. 273: 24737-24743, 1998). A human homolog (hAQP9) with 76%
      amino acid sequence identity to rat AQP9 (rAQP9) was described, but its
      permeability was found to be restricted to water and urea (K. Ishibashi, M.
      Kuwahara, Y. Gu, Y. Tanaka, F. Marumo, and S. Sasaki. Biochem. Biophys. Res.
      Commun. 244: 268-274, 1998). Here we report a reevaluation of the functional
      characteristics of hAQP9, its tissue distribution, the structure of its gene, and
      its chromosomal localization. When expressed in Xenopus oocytes, hAQP9 allowed
      passage of a wide variety of noncharged solutes, including carbamides, polyols,
      purines, and pyrimidines in a phloretin- and mercurial-sensitive manner. These
      functional characteristics are similar to those of rAQP9. Based on Northern blot 
      analysis, both rat and human AQP9 are abundantly expressed in liver, whereas, in 
      contrast to rAQP9, hAQP9 is also expressed in peripheral leukocytes and in
      tissues that accumulate leukocytes, such as lung, spleen, and bone marrow. The
      human AQP9 gene is composed of 6 exons and 5 introns distributed over
      approximately approximately 25 kb. The gene organization is strikingly similar to
      that reported for human AQP3 and AQP7, suggesting their evolution from a common
      ancestral gene. The promoter region contains putative tonicity and
      glucocorticoid-responsive elements, suggesting that AQP9 may be regulated by
      osmolality and catabolism. Fluorescence in situ hybridization assigned its locus 
      to chromosome 15 q22.1-22.2. Our data show that hAQP9 serves as a promiscuous
      solute channel expressed in both liver and peripheral leukocytes, where it is
      ideally suited to transport of metabolites and/or nutrients into and out of these
      cells
FAU - Tsukaguchi, H
AU  - Tsukaguchi H
AD  - Membrane Biology Program, Department of Medicine, Brigham and Women's Hospital
      and Harvard Medical School, Boston, Massachusetts 02115, USA.
FAU - Weremowicz, S
AU  - Weremowicz S
FAU - Morton, C C
AU  - Morton CC
FAU - Hediger, M A
AU  - Hediger MA
LA  - eng
GR  - R01-DK-46289/DK/NIDDK NIH HHS/United States
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - Am J Physiol
JT  - The American journal of physiology
JID - 0370511
RN  - 0 (AQP9 protein, human)
RN  - 0 (Aqp9 protein, rat)
RN  - 0 (Aquaporins)
RN  - 0 (DNA, Complementary)
SB  - IM
MH  - Amino Acid Sequence/genetics
MH  - Animals
MH  - Aquaporins/*genetics/metabolism/*physiology
MH  - Base Sequence/genetics
MH  - Chromosome Mapping
MH  - Cloning, Molecular
MH  - DNA, Complementary/genetics
MH  - Exons/genetics
MH  - Female
MH  - Genome, Human
MH  - Humans
MH  - Introns/genetics
MH  - Molecular Sequence Data
MH  - Oocytes/metabolism
MH  - Tissue Distribution
MH  - Transcription, Genetic
MH  - Xenopus laevis
EDAT- 1999/11/24 00:00
MHDA- 1999/11/24 00:01
CRDT- 1999/11/24 00:00
PHST- 1999/11/24 00:00 [pubmed]
PHST- 1999/11/24 00:01 [medline]
PHST- 1999/11/24 00:00 [entrez]
AID - 10.1152/ajprenal.1999.277.5.F685 [doi]
PST - ppublish
SO  - Am J Physiol. 1999 Nov;277(5):F685-96. doi: 10.1152/ajprenal.1999.277.5.F685.