PMID- 19879980
OWN - NLM
STAT- MEDLINE
DCOM- 20100401
LR  - 20211020
IS  - 0006-3002 (Print)
IS  - 0006-3002 (Linking)
VI  - 1804
IP  - 2
DP  - 2010 Feb
TI  - Evaluating the role of carbonic anhydrases in the transport of HCO3--related 
      species.
PG  - 410-21
LID - 10.1016/j.bbapap.2009.10.021 [doi]
AB  - The soluble enzyme carbonic anhydrase II (CAII) plays an important role in CO(2) 
      influx and efflux by red blood cells (RBCs), a process initiated by changes in 
      the extracellular [CO(2)] (CO(2)-initiated CO(2) transport). Evidence suggests 
      that CAII may be part of a macromolecular complex at the inner surface of the RBC 
      membrane. Some have suggested CAII specifically binds to a motif on the 
      cytoplasmic C terminus (Ct) of the Cl-HCO(3) exchanger AE1 and some other members 
      of the SLC4 family of HCO(3)(-) transporters, a transport metabolon. Moreover, 
      others have suggested that this bound CAII enhances the transport of 
      HCO(3)(-)-related species-HCO(3)(-), CO(3)(), or CO(3)() ion pairs-when the 
      process is initiated by altering the activity of the transporter 
      (HCO(3)(-)-initiated HCO(3)(-) transport). In this review, I assess the 
      theoretical roles of CAs in the transport of CO(2) and HCO(3)(-)-related species, 
      concluding that although the effect of bound CAII on CO(2)-initiated CO(2) 
      transport is expected to be substantial, the effect of bound CAs on 
      HCO(3)(-)-initiated HCO(3)(-) transport is expected to be modest at best. I also 
      assess the experimental evidence for CAII binding to AE1 and other transporters, 
      and the effects of this binding on HCO(3)(-)-initiated HCO(3)(-) transport. The 
      early conclusion that CAII binds to the Ct of AE1 appears to be the result of 
      unpredictable effects of GST in the GST fusion proteins used in the studies. The 
      early conclusion that bound CAII speeds HCO(3)(-)-initiated HCO(3)(-) transport 
      appears to be the result of CAII accelerating the pH changes used as a read-out 
      of transport. Thus, it appears that CAII does not bind directly to AE1 or other 
      SLC4 proteins, and that bound CAII does not substantially accelerate 
      HCO(3)(-)-initiated HCO(3)(-) transport.
CI  - Copyright 2009. Published by Elsevier B.V.
FAU - Boron, Walter F
AU  - Boron WF
AD  - Department of Physiology and Biophysics, Case Western Reserve University School 
      of Medicine, Cleveland, OH 44106-4970, USA. walter.boron@case.edu
LA  - eng
GR  - R01 NS018400/NS/NINDS NIH HHS/United States
GR  - R01 DK030344/DK/NIDDK NIH HHS/United States
GR  - R01 DK081567/DK/NIDDK NIH HHS/United States
GR  - R37 DK030344/DK/NIDDK NIH HHS/United States
GR  - DK30344/DK/NIDDK NIH HHS/United States
GR  - R37 DK030344-28/DK/NIDDK NIH HHS/United States
GR  - R01 NS018400-20/NS/NINDS NIH HHS/United States
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
PT  - Review
DEP - 20091030
PL  - Netherlands
TA  - Biochim Biophys Acta
JT  - Biochimica et biophysica acta
JID - 0217513
RN  - 0 (Bicarbonates)
RN  - EC 4.2.1.1 (Carbonic Anhydrases)
SB  - IM
MH  - Animals
MH  - Bicarbonates/*metabolism
MH  - Biological Transport
MH  - Carbonic Anhydrases/*physiology
MH  - Erythrocytes/metabolism
MH  - Humans
PMC - PMC4699190
MID - NIHMS604657
EDAT- 2009/11/03 06:00
MHDA- 2010/04/02 06:00
PMCR- 2016/01/04
CRDT- 2009/11/03 06:00
PHST- 2009/09/11 00:00 [received]
PHST- 2009/10/23 00:00 [revised]
PHST- 2009/10/23 00:00 [accepted]
PHST- 2009/11/03 06:00 [entrez]
PHST- 2009/11/03 06:00 [pubmed]
PHST- 2010/04/02 06:00 [medline]
PHST- 2016/01/04 00:00 [pmc-release]
AID - S1570-9639(09)00310-0 [pii]
AID - 10.1016/j.bbapap.2009.10.021 [doi]
PST - ppublish
SO  - Biochim Biophys Acta. 2010 Feb;1804(2):410-21. doi: 10.1016/j.bbapap.2009.10.021. 
      Epub 2009 Oct 30.