PMID- 21191106
OWN - NLM
STAT- MEDLINE
DCOM- 20110520
LR  - 20211020
IS  - 1522-1563 (Electronic)
IS  - 0363-6143 (Print)
IS  - 0363-6143 (Linking)
VI  - 300
IP  - 4
DP  - 2011 Apr
TI  - NHERF1 and NHERF2 are necessary for multiple but usually separate aspects of 
      basal and acute regulation of NHE3 activity.
PG  - C771-82
LID - 10.1152/ajpcell.00119.2010 [doi]
AB  - Na(+)/H(+) exchanger 3 (NHE3) is expressed in the brush border (BB) of intestinal 
      epithelial cells and accounts for the majority of neutral NaCl absorption. It has 
      been shown that the Na(+)/H(+) exchanger regulatory factor (NHERF) family members 
      of multi-PDZ domain-containing scaffold proteins bind to the NHE3 COOH terminus 
      and play necessary roles in NHE3 regulation in intestinal epithelial cells. Most 
      studies of NHE3 regulation have been in cell models in which NHERF1 and/or NHERF2 
      were overexpressed. We have now developed an intestinal Na(+) absorptive cell 
      model in Caco-2/bbe cells by expressing hemagglutinin (HA)-tagged NHE3 with an 
      adenoviral infection system. Roles of NHERF1 and NHERF2 in NHE3 regulation were 
      determined, including inhibition by cAMP, cGMP, and Ca(2+) and stimulation by 
      EGF, with knockdown (KD) approaches with lentivirus (Lenti)-short hairpin RNA 
      (shRNA) and/or adenovirus (Adeno)-small interfering RNA (siRNA). Stable infection 
      of Caco-2/bbe cells by NHERF1 or NHERF2 Lenti-shRNA significantly and 
      specifically reduced NHERF protein expression by >80%. NHERF1 KD reduced basal 
      NHE3 activity, while NHERF2 KD stimulated NHE3 activity. siRNA-mediated 
      (transient) and Lenti-shRNA-mediated (stable) gene silencing of NHERF2 (but not 
      of NHERF1) abolished cGMP- and Ca(2+)-dependent inhibition of NHE3. KD of NHERF1 
      or NHERF2 alone had no effect on cAMP inhibition of NHE3, but KD of both 
      simultaneously abolished the effect of cAMP. The stimulatory effect of EGF on 
      NHE3 was eliminated in NHERF1-KD but occurred normally in NHERF2-KD cells. These 
      findings show that both NHERF2 and NHERF1 are involved in setting NHE3 activity. 
      NHERF2 is necessary for cGMP-dependent protein kinase (cGK) II- and 
      Ca(2+)-dependent inhibition of NHE3. cAMP-dependent inhibition of NHE3 activity 
      requires either NHERF1 or NHERF2. Stimulation of NHE3 activity by EGF is NHERF1 
      dependent.
FAU - Sarker, Rafiquel
AU  - Sarker R
AD  - Gastroenterology and Hepatology Division, Department of Medicine, Johns Hopkins 
      Univ. School of Medicine, Baltimore, MD 21205-2195, USA.
FAU - Valkhoff, Vera E
AU  - Valkhoff VE
FAU - Zachos, Nicholas C
AU  - Zachos NC
FAU - Lin, Rong
AU  - Lin R
FAU - Cha, Boyoung
AU  - Cha B
FAU - Chen, Tian-e
AU  - Chen TE
FAU - Guggino, Sandra
AU  - Guggino S
FAU - Zizak, Mirza
AU  - Zizak M
FAU - de Jonge, Hugo
AU  - de Jonge H
FAU - Hogema, Boris
AU  - Hogema B
FAU - Donowitz, Mark
AU  - Donowitz M
LA  - eng
GR  - R01-DK-61765/DK/NIDDK NIH HHS/United States
GR  - R03 DK091482/DK/NIDDK NIH HHS/United States
GR  - R01 DK026523/DK/NIDDK NIH HHS/United States
GR  - P01-DK-072084/DK/NIDDK NIH HHS/United States
GR  - R01-DK-26523/DK/NIDDK NIH HHS/United States
GR  - T32-DK-2007632/DK/NIDDK NIH HHS/United States
GR  - R24-DK-64388/DK/NIDDK NIH HHS/United States
GR  - R01 DK061765/DK/NIDDK NIH HHS/United States
GR  - K01 DK080930/DK/NIDDK NIH HHS/United States
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
PT  - Research Support, Non-U.S. Gov't
DEP - 20101229
PL  - United States
TA  - Am J Physiol Cell Physiol
JT  - American journal of physiology. Cell physiology
JID - 100901225
RN  - 0 (Cholinergic Agonists)
RN  - 0 (Phosphoproteins)
RN  - 0 (RNA, Small Interfering)
RN  - 0 (SLC9A3 protein, human)
RN  - 0 (Slc9a3 protein, mouse)
RN  - 0 (Sodium-Hydrogen Exchanger 3)
RN  - 0 (Sodium-Hydrogen Exchangers)
RN  - 0 (sodium-hydrogen exchanger regulatory factor)
RN  - 62229-50-9 (Epidermal Growth Factor)
RN  - 8Y164V895Y (Carbachol)
RN  - E0399OZS9N (Cyclic AMP)
RN  - H2D2X058MU (Cyclic GMP)
SB  - IM
MH  - Adenoviridae/genetics/metabolism
MH  - Animals
MH  - Caco-2 Cells
MH  - Carbachol/metabolism
MH  - Cholinergic Agonists/metabolism
MH  - Cyclic AMP/metabolism
MH  - Cyclic GMP/metabolism
MH  - Epidermal Growth Factor/metabolism
MH  - Epithelial Cells/cytology/metabolism
MH  - Genetic Vectors
MH  - Humans
MH  - Mice
MH  - Microvilli/metabolism
MH  - Phosphoproteins/genetics/*metabolism
MH  - RNA, Small Interfering/genetics/metabolism
MH  - Sodium-Hydrogen Exchanger 3
MH  - Sodium-Hydrogen Exchangers/antagonists & inhibitors/genetics/*metabolism
PMC - PMC3074635
EDAT- 2010/12/31 06:00
MHDA- 2011/05/21 06:00
PMCR- 2012/04/01
CRDT- 2010/12/31 06:00
PHST- 2010/12/31 06:00 [entrez]
PHST- 2010/12/31 06:00 [pubmed]
PHST- 2011/05/21 06:00 [medline]
PHST- 2012/04/01 00:00 [pmc-release]
AID - ajpcell.00119.2010 [pii]
AID - C-00119-2010 [pii]
AID - 10.1152/ajpcell.00119.2010 [doi]
PST - ppublish
SO  - Am J Physiol Cell Physiol. 2011 Apr;300(4):C771-82. doi: 
      10.1152/ajpcell.00119.2010. Epub 2010 Dec 29.