PMID- 10318966
OWN - NLM
STAT- MEDLINE
DCOM- 19990617
LR  - 20191003
IS  - 0027-8424 (Print)
IS  - 0027-8424 (Linking)
VI  - 96
IP  - 10
DP  - 1999 May 11
TI  - Aquaporin-6: An intracellular vesicle water channel protein in renal epithelia.
PG  - 5808-13
AB  - All characterized mammalian aquaporins (AQPs) are localized to plasma membranes
      where they function chiefly to mediate water transport across cells. Here we show
      that AQP6 is localized exclusively in intracellular membranes in renal epithelia.
      By using a polyclonal antibody to the C terminus of AQP6, immunoblots revealed a 
      major 30-kDa band in membranes from rat renal cortex and medulla. Endoglycosidase
      treatment demonstrated presence of an intracellular high mannose glycan on each
      subunit. Sequential ultracentrifugation of rat kidney homogenates confirmed that 
      AQP6 resides predominantly in vesicular fractions, and immunohistochemical and
      immunoelectron microscopic studies confirmed that >98% of AQP6 is located in
      intracellular membrane vesicles. In glomeruli, AQP6 is present in membrane
      vesicles within podocyte cell bodies and foot processes. In proximal tubules,
      AQP6 is also abundant in membrane vesicles within the subapical compartment of
      segment 2 and segment 3 cells, but was not detected in the brush border or
      basolateral membranes. In collecting duct, AQP6 resides in intracellular membrane
      vesicles in apical, mid, and basolateral cytoplasm of type A intercalated cells, 
      but was not observed in the plasma membrane. Unlike other members of the AQP
      family, the unique distribution in intracellular membrane vesicles in multiple
      types of renal epithelia indicates that AQP6 is not simply involved in
      transcellular fluid absorption. Moreover, our studies predict that AQP6
      participates in distinct physiological functions such as glomerular filtration,
      tubular endocytosis, and acid-base metabolism.
FAU - Yasui, M
AU  - Yasui M
AD  - Departments of Biological Chemistry and Medicine, Johns Hopkins University School
      of Medicine, Baltimore, MD 21205-2185, USA.
FAU - Kwon, T H
AU  - Kwon TH
FAU - Knepper, M A
AU  - Knepper MA
FAU - Nielsen, S
AU  - Nielsen S
FAU - Agre, P
AU  - Agre P
LA  - eng
SI  - GENBANK/AF083879
GR  - Z01 HL001285-21/Intramural NIH HHS/United States
GR  - Z99 HL999999/Intramural NIH HHS/United States
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - Proc Natl Acad Sci U S A
JT  - Proceedings of the National Academy of Sciences of the United States of America
JID - 7505876
RN  - 0 (Aqp2 protein, rat)
RN  - 0 (Aqp6 protein, rat)
RN  - 0 (Aquaporin 2)
RN  - 0 (Aquaporin 6)
RN  - 0 (Aquaporins)
RN  - 0 (Membrane Glycoproteins)
RN  - EC 3.5.- (Amidohydrolases)
RN  - EC 3.5.1.52 (Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase)
SB  - IM
MH  - Amidohydrolases/metabolism
MH  - Amino Acid Sequence
MH  - Animals
MH  - Aquaporin 2
MH  - Aquaporin 6
MH  - Aquaporins/*metabolism
MH  - Cell Membrane/metabolism
MH  - Kidney Cortex/*metabolism
MH  - Kidney Glomerulus/chemistry
MH  - Kidney Tubules/chemistry
MH  - Membrane Glycoproteins/chemistry
MH  - Molecular Sequence Data
MH  - Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase
MH  - Rats
PMC - PMC21942
EDAT- 1999/05/13 00:00
MHDA- 1999/05/13 00:01
CRDT- 1999/05/13 00:00
PHST- 1999/05/13 00:00 [pubmed]
PHST- 1999/05/13 00:01 [medline]
PHST- 1999/05/13 00:00 [entrez]
AID - 10.1073/pnas.96.10.5808 [doi]
PST - ppublish
SO  - Proc Natl Acad Sci U S A. 1999 May 11;96(10):5808-13. doi:
      10.1073/pnas.96.10.5808.