Linked Life Data

10430655

Source:http://linkedlifedata.com/resource/pubmed/id/10430655

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1999-9-24
pubmed:abstractText
The activation kinetics of outward currents in protoplasts from barley root xylem parenchyma was investigated using the patch-clamp technique. The K(+) outward rectifying conductance (KORC), providing the main pathway for K(+) transport to the xylem, could be described in terms of a Hodgkin-Huxley model with four independent gates. Gating of KORC depended on voltage and the external K(+) concentration. An increase in the external K(+) concentration resulted in a shift in the voltage dependence of gating. This could be explained by a K(+) dependence of the rate constant beta for channel closure, indicating binding of K(+) to a regulatory site exposed to the bath. Occasionally, KORC was observed to inactivate; this inactivation occurred and vanished spontaneously. In some of the whole cell and excised patch recordings, a stepwise increase in outward current was observed upon a depolarizing voltage pulse, indicating that several populations of 'sleepy' channels existed in the plasma membrane that activated with a certain lag time. It is discussed whether this observation can be explained by a putative subunit, which retards channel activation, or by a scheme of cooperative gating. A quantitative description of outward rectifying K(+) channels in xylem parenchyma cells is a major step forward towards a mathematical model of salt transport into the xylem.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0022-2631
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
170
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
103-19
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Activation kinetics of the K(+) outward rectifying conductance (KORC) in xylem parenchyma cells from barley roots.
pubmed:affiliation
Faculty of Biology, Department of Molecular Genetics, Section of Plant Physiology, Vrije Universiteit Amsterdam, De Boelelaan 1087, 1081HV Amsterdam, The Netherlands.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't