PMID- 10409305
OWN - NLM
STAT- MEDLINE
DCOM- 19990830
LR  - 20181106
IS  - 0002-9513 (Print)
IS  - 0002-9513 (Linking)
VI  - 277
IP  - 1
DP  - 1999 Jul
TI  - Cloning and functional expression of the mouse epithelial sodium channel.
PG  - F121-9
LID - 10.1152/ajprenal.1999.277.1.F121 [doi]
AB  - The epithelial sodium channel (ENaC) plays a major role in the transepithelial
      reabsorption of sodium in the renal cortical collecting duct, distal colon, and
      lung. ENaCs are formed by three structurally related subunits, termed alpha-,
      beta-, and gammaENaC. We previously isolated and sequenced cDNAs encoding a
      portion of mouse alpha-, beta-, and gammaENaC (alpha-, beta-, and gammamENaC).
      These cDNAs were used to screen an oligo-dT-primed mouse kidney cDNA library.
      Full-length betamENaC and partial-length alpha- and gammamENaC clones were
      isolated. Full-length alpha- and gammamENaC cDNAs were subsequently obtained by
      5'-rapid amplification of cDNA ends (5'-RACE) PCR. Injection of mouse alpha-,
      beta-, and gammaENaC cRNAs into Xenopus oocytes led to expression of
      amiloride-sensitive (K(i) = 103 nM), Na(+)-selective currents with a
      single-channel conductance of 4.7 pS. Northern blots revealed that alpha-, beta-,
      and gammamENaC were expressed in lung and kidney. Interestingly, alphamENaC was
      detected in liver, although transcript sizes of 9.8 kb and 3.1 kb differed in
      size from the 3.2-kb message observed in other tissues. A partial cDNA clone was 
      isolated from mouse liver by 5'-RACE PCR. Its sequence was found to be nearly
      identical to alphamENaC. To begin to identify regions within alphamENaC that
      might be important in assembly of the native heteroligomeric channel, a series of
      functional experiments were performed using a construct of alphamENaC encoding
      the predicted cytoplasmic NH(2) terminus. Coinjection of wild-type alpha-, beta-,
      and gammamENaC with the intracellular NH(2) terminus of alphamENaC abolished
      amiloride-sensitive currents in Xenopus oocytes, suggesting that the NH(2)
      terminus of alphamENaC is involved in subunit assembly, and when present in a
      10-fold excess, plays a dominant negative role in functional ENaC expression.
FAU - Ahn, Y J
AU  - Ahn YJ
AD  - Departments of Medicine and Physiology, University of Pennsylvania, and Veterans 
      Affairs Medical Center, Philadelphia, Pennsylvania 19104-6144, USA.
      yahn@mail.med.upenn.edu
FAU - Brooker, D R
AU  - Brooker DR
FAU - Kosari, F
AU  - Kosari F
FAU - Harte, B J
AU  - Harte BJ
FAU - Li, J
AU  - Li J
FAU - Mackler, S A
AU  - Mackler SA
FAU - Kleyman, T R
AU  - Kleyman TR
LA  - eng
SI  - GENBANK/AF112185
SI  - GENBANK/AF112186
SI  - GENBANK/AF112187
GR  - DK-51391/DK/NIDDK NIH HHS/United States
GR  - DK-54354/DK/NIDDK NIH HHS/United States
GR  - HL-07027/HL/NHLBI 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 (Sodium Channels)
SB  - IM
MH  - Amino Acid Sequence
MH  - Animals
MH  - Cloning, Molecular
MH  - Epithelium/metabolism
MH  - Mice
MH  - Molecular Sequence Data
MH  - Oocytes/metabolism
MH  - Sodium Channels/*metabolism
MH  - Xenopus
EDAT- 1999/07/17 00:00
MHDA- 1999/07/17 00:01
CRDT- 1999/07/17 00:00
PHST- 1999/07/17 00:00 [pubmed]
PHST- 1999/07/17 00:01 [medline]
PHST- 1999/07/17 00:00 [entrez]
AID - 10.1152/ajprenal.1999.277.1.F121 [doi]
PST - ppublish
SO  - Am J Physiol. 1999 Jul;277(1):F121-9. doi: 10.1152/ajprenal.1999.277.1.F121.