Linked Life Data

9873001

Source:http://linkedlifedata.com/resource/pubmed/id/9873001

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1999-2-5
pubmed:abstractText
The vesicular acetylcholine transporter (VAChT) is responsible for the transport of the neurotransmitter acetylcholine (ACh) into synaptic vesicles using an electrochemical gradient to drive transport. Rat VAChT has a number of aspartate residues within its predicted transmembrane domains (TM) and cytoplasmic loops, which may play important structural or functional roles in acetylcholine transport. In order to identify functional charged residues, site-directed mutagenesis of rVAChT was undertaken. No effect on ACh transport was observed when any of the five aspartate residues in the cytoplasmic loop were converted to asparagine. Similarly, changing Asp-46 (D46N) in TM1 or Asp-255 (D255N) in TM6 had no effect on ACh transport or vesamicol binding. However, replacement of Asp-398 in TM10 with Asn completely eliminated both ACh transport and vesamicol binding. The conservative mutant D398E retained transport activity, but not vesamicol binding, suggesting this residue is critical for transport. Mutation of Asp-193 in TM4 did not affect ACh transport activity; however, vesamicol binding was dramatically reduced. With mutant D425N of TM11 transport activity for ACh was completely blocked, without an effect on vesamicol binding. Activity was not restored in the conservative mutant D425E, suggesting the side chain as well as the negative charge of Asp-425 is important for substrate binding. These mutants, as well as mutant D193N, clearly dissociated ACh binding and transport from vesamicol binding. These data suggest that Asp-398 in TM10 and Asp-425 in TM11 are important for ACh binding and transport, while Asp-193 and Asp-398 in TM4 and TM10, respectively, are involved in vesamicol binding.
pubmed:grant
pubmed:commentsCorrections
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
8
pubmed:volume
274
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
673-80
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Mutational analysis of aspartate residues in the transmembrane regions and cytoplasmic loops of rat vesicular acetylcholine transporter.
pubmed:affiliation
Department of Biochemistry, University of Kentucky, Lexington, Kentucky 40536, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.