Linked Life Data

21680735

Source:http://linkedlifedata.com/resource/pubmed/id/21680735

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
31
pubmed:dateCreated
2011-8-1
pubmed:abstractText
The ubiquitous enzyme carbonic anhydrase isoform II (CAII) has been shown to enhance transport activity of the proton-coupled monocarboxylate transporters MCT1 and MCT4 in a non-catalytic manner. In this study, we investigated the role of cytosolic CAII and of the extracellular, membrane-bound CA isoform IV (CAIV) on the lactate transport activity of the high-affinity monocarboxylate transporter MCT2, heterologously expressed in Xenopus oocytes. In contrast to MCT1 and MCT4, transport activity of MCT2 was not altered by CAII. However, coexpression of CAIV with MCT2 resulted in a significant increase in MCT2 transport activity when the transporter was coexpressed with its associated ancillary protein GP70 (embigin). The CAIV-mediated augmentation of MCT2 activity was independent of the catalytic activity of the enzyme, as application of the CA-inhibitor ethoxyzolamide or coexpressing the catalytically inactive mutant CAIV-V165Y did not suppress CAIV-mediated augmentation of MCT2 transport activity. Furthermore, exchange of His-88, mediating an intramolecular H(+)-shuttle in CAIV, to alanine resulted only in a slight decrease in CAIV-mediated augmentation of MCT2 activity. The data suggest that extracellular membrane-bound CAIV, but not cytosolic CAII, augments transport activity of MCT2 in a non-catalytic manner, possibly by facilitating a proton pathway other than His-88.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
1083-351X
pubmed:author
pubmed:issnType
Electronic
pubmed:day
5
pubmed:volume
286
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
27781-91
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Transport activity of the high-affinity monocarboxylate transporter MCT2 is enhanced by extracellular carbonic anhydrase IV but not by intracellular carbonic anhydrase II.
pubmed:affiliation
Abteilung für Allgemeine Zoologie, Fachbereich Biologie, Technische Universität Kaiserslautern, P. O. Box 3049, 67653 Kaiserslautern, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't