PMID- 21880864
OWN - NLM
STAT- MEDLINE
DCOM- 20111222
LR  - 20211020
IS  - 1522-1490 (Electronic)
IS  - 0363-6119 (Print)
IS  - 0363-6119 (Linking)
VI  - 301
IP  - 5
DP  - 2011 Nov
TI  - Identification and apical membrane localization of an electrogenic Na(+)/Ca(2)(+) 
      exchanger NCX2a likely to be involved in renal Ca(2)(+) excretion by seawater fish.
PG  - R1427-39
LID - 10.1152/ajpregu.00165.2011 [doi]
AB  - Seawater (SW) contains  approximately 10 mM Ca(2+), yet marine fish must drink seawater as 
      their major water source. Thus marine teleosts fish need to excrete Ca(2+) to 
      maintain whole body Ca(2+) homeostasis. In the intestine, seawater Ca(2+) 
      interreacts with epithelial-secreted HCO(3)(-) by the intestinal epithelium, and 
      the resulting CaCO(3) precipitates, which is rectally excreted. Recently the 
      transporters involved in intestinal HCO(3)(-) secretion were identified. Ca(2+) 
      is also excreted by the kidney, but the protein(s) involved in renal Ca(2+) 
      excretion have not been identified. Here we identified a candidate transporter by 
      using SW pufferfish torafugu (Takifugu rubripes) and its closely related 
      euryhaline species mefugu (Takifugu obscurus), which are becoming useful animal 
      models for studying molecular mechanisms of seawater adaptation. RT-PCR analyses 
      of Na(+)/Ca(2+) exchanger (NCX) family members in various torafugu tissues 
      demonstrated that only NCX2a is highly expressed in the kidney. Renal expression 
      of NCX2a was markedly elevated when mefugu were transferred from freshwater to 
      seawater. In situ hybridization and immunohistochemical analyses indicated that 
      NCX2a is expressed in the proximal tubule at the apical membrane. NCX2a, 
      expressed in Xenopus oocytes, conferred [Ca(2+)](out)- and Na(+)-dependent 
      currents. These results suggest that NCX2a mediates renal Ca(2+) secretion at the 
      apical membrane of renal proximal tubules and has an important role in whole body 
      Ca(2+) homeostasis of marine teleosts.
FAU - Islam, Zinia
AU  - Islam Z
AD  - Department of Biological Sciences, Tokyo Institute of Technology, Midori-ku, 
      Yokohama, Japan.
FAU - Kato, Akira
AU  - Kato A
FAU - Romero, Michael F
AU  - Romero MF
FAU - Hirose, Shigehisa
AU  - Hirose S
LA  - eng
GR  - DK083007/DK/NIDDK NIH HHS/United States
GR  - DK090728/DK/NIDDK NIH HHS/United States
GR  - EY017732/EY/NEI NIH HHS/United States
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
PT  - Research Support, Non-U.S. Gov't
DEP - 20110831
PL  - United States
TA  - Am J Physiol Regul Integr Comp Physiol
JT  - American journal of physiology. Regulatory, integrative and comparative 
      physiology
JID - 100901230
RN  - 0 (Fish Proteins)
RN  - 0 (RNA, Messenger)
RN  - 0 (Sodium-Calcium Exchanger)
RN  - 9NEZ333N27 (Sodium)
RN  - SY7Q814VUP (Calcium)
SB  - IM
MH  - Amino Acid Sequence
MH  - Animals
MH  - Calcium/blood/*metabolism/urine
MH  - Cell Membrane/*metabolism
MH  - Female
MH  - Fish Proteins/genetics/*metabolism
MH  - Homeostasis
MH  - Immunohistochemistry
MH  - In Situ Hybridization
MH  - Kidney/*metabolism
MH  - Molecular Sequence Data
MH  - Oocytes
MH  - Phylogeny
MH  - RNA, Messenger/metabolism
MH  - Real-Time Polymerase Chain Reaction
MH  - Reverse Transcriptase Polymerase Chain Reaction
MH  - Seawater
MH  - Sodium/*metabolism
MH  - Sodium-Calcium Exchanger/genetics/*metabolism
MH  - Takifugu/genetics/*metabolism
MH  - Xenopus laevis
PMC - PMC3213929
EDAT- 2011/09/02 06:00
MHDA- 2011/12/23 06:00
PMCR- 2012/11/01
CRDT- 2011/09/02 06:00
PHST- 2011/09/02 06:00 [entrez]
PHST- 2011/09/02 06:00 [pubmed]
PHST- 2011/12/23 06:00 [medline]
PHST- 2012/11/01 00:00 [pmc-release]
AID - ajpregu.00165.2011 [pii]
AID - R-00165-2011 [pii]
AID - 10.1152/ajpregu.00165.2011 [doi]
PST - ppublish
SO  - Am J Physiol Regul Integr Comp Physiol. 2011 Nov;301(5):R1427-39. doi: 
      10.1152/ajpregu.00165.2011. Epub 2011 Aug 31.