Linked Life Data

18379771

Source:http://linkedlifedata.com/resource/pubmed/id/18379771

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2009-2-17
pubmed:abstractText
The ether-à-go-go potassium channels hEag1 and hEag2 are highly homologous. Even though both possess identical voltage-sensing domain S4, the channels act differently in response to voltage. Therefore we asked whether transmembrane domains other than the voltage sensor could contribute to the voltage-dependent behaviour of these potassium channels. For this chimaeras were created, in which each single transmembrane domain of hEag1 was replaced by the corresponding segment of hEag2. The voltage-dependent properties of the chimaeras were analysed after expression in Xenopus laevis oocytes using the two-electrode voltage-clamp method. By this we found, that only the mutations in transmembrane domains S5 and S6 are able to change the voltage sensitivity of hEag1 by shifting the half-activation potential (V(50)) to values intermediate between the two wild types. Moreover, the presence of Mg2+ has strong effects on the voltage sensitivity of hEag2 shifting V(50) by more than 50 mV to more positive values. Interestingly, despite the identical binding site Mg2+ showed only little effects on hEag1 or the chimaeras. Altogether, our data suggest that not only transmembrane spanning regions, but also non-membrane spanning regions are responsible for differences in the behaviour of the hEag1 and hEag2 potassium channels.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1432-1017
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
38
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
279-84
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
The voltage dependence of hEag currents is not determined solely by membrane-spanning domains.
pubmed:affiliation
Max-Planck Institute of Experimental Medicine, Hermann-Rein Str. 3, 37075 Göttingen, Germany.
pubmed:publicationType
Journal Article