Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2006-1-23
pubmed:abstractText
The mouse anion exchanger AE2/SLC4A2 Cl(-)/HCO(-)(3) exchanger is essential to post-weaning life. AE2 polypeptides regulate pH(i), chloride concentration, cell volume, and transepithelial ion transport in many tissues. Although the AE2a isoform has been extensively studied, the function and regulation of the other AE2 N-terminal variant mRNAs of mouse (AE2b1, AE2b2, AE2c1, and AE2c2) have not been examined. We now present an extended analysis of AE2 variant mRNA tissue distribution and function. We show in Xenopus oocytes that all AE2 variant polypeptides except AE2c2 mediated Cl(-) transport are subject to inhibition by acidic pH(i) and to activation by hypertonicity and NH(+)(4). However, AE2c1 differs from AE2a, AE2b1, and AE2b2 in its alkaline-shifted pH(o)((50)) (7.70 +/- 0.11 versus 6.80 +/- 0.05), suggesting the presence of a novel AE2a pH-sensitive regulatory site between amino acids 99 and 198. Initial N-terminal deletion mutagenesis restricted this site to the region between amino acids 120 and 150. Further analysis identified AE2a residues 127-129, 130-134, and 145-149 as jointly responsible for the difference in pH(o)((50)) between AE2c1 and the longer AE2a, AE2b1, and AE2b2 polypeptides. Thus, AE2c1 exhibits a unique pH(o) sensitivity among the murine AE2 variant polypeptides, in addition to a unique tissue distribution. Physiological coexpression of AE2c1 with other AE2 variant polypeptides in the same cell should extend the range over which changing pH(o) can regulate AE2 transport activity.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
27
pubmed:volume
281
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1885-96
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:16286476-Animals, pubmed-meshheading:16286476-Anion Transport Proteins, pubmed-meshheading:16286476-Antiporters, pubmed-meshheading:16286476-Cell Line, pubmed-meshheading:16286476-Chromatography, Ion Exchange, pubmed-meshheading:16286476-Cytoplasm, pubmed-meshheading:16286476-DNA, Complementary, pubmed-meshheading:16286476-Gene Deletion, pubmed-meshheading:16286476-Genetic Variation, pubmed-meshheading:16286476-Humans, pubmed-meshheading:16286476-Hydrogen-Ion Concentration, pubmed-meshheading:16286476-Mice, pubmed-meshheading:16286476-Mutagenesis, pubmed-meshheading:16286476-Mutagenesis, Site-Directed, pubmed-meshheading:16286476-Mutation, pubmed-meshheading:16286476-Oocytes, pubmed-meshheading:16286476-Peptides, pubmed-meshheading:16286476-Protein Structure, Tertiary, pubmed-meshheading:16286476-RNA, Messenger, pubmed-meshheading:16286476-Reverse Transcriptase Polymerase Chain Reaction, pubmed-meshheading:16286476-Tissue Distribution, pubmed-meshheading:16286476-Transcription, Genetic, pubmed-meshheading:16286476-Xenopus
pubmed:year
2006
pubmed:articleTitle
Alkaline-shifted pHo sensitivity of AE2c1-mediated anion exchange reveals novel regulatory determinants in the AE2 N-terminal cytoplasmic domain.
pubmed:affiliation
Molecular and Vascular Medicine and Renal Units, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Boston, MA 02215, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural