|
rdf:type |
|
|
lifeskim:mentions |
|
|
pubmed:dateCreated |
1995-2-16
|
|
pubmed:abstractText |
The midgut of the tobacco hornworm secretes K+ across the apical plasma membrane of its goblet cells. This secondary K+ transport results from K+/H+ antiport energized by the proton-motive force generated by a primary, H(+)-transporting plasma membrane V-ATPase. Thus, the lepidopteran midgut constitutes a well-established example of the emerging concept that the proton-motive force is an alternative to the classical sodium-motive force for the energization of animal plasma membranes. K+/H+ antiport in the tobacco hornworm midgut is electrophoretic, exchanging 2H+ for 1K+. Under physiological conditions, it is energized by the voltage component of the proton-motive force. The strong coupling of electrophoretic K+/2H+ antiport with the electrogenic V-ATPase provides, in principle, the minimal device for the alkalization of the midgut lumen to pH values higher than 11. K+/H+ antiport is insensitive to bafilomycin A1, but is inhibited by amiloride or Concanavalin A. Lectin staining of blots after SDS-PAGE revealed several glycosylated polypeptides in the goblet cell apical membrane which are not part of the V-ATPase and thus are candidates for the antiporter protein. Current efforts are focused on the isolation of the K+/H+ antiporter.
|
|
pubmed:grant |
|
|
pubmed:language |
eng
|
|
pubmed:journal |
|
|
pubmed:citationSubset |
IM
|
|
pubmed:chemical |
|
|
pubmed:status |
MEDLINE
|
|
pubmed:month |
Nov
|
|
pubmed:issn |
0022-0949
|
|
pubmed:author |
|
|
pubmed:issnType |
Print
|
|
pubmed:volume |
196
|
|
pubmed:owner |
NLM
|
|
pubmed:authorsComplete |
Y
|
|
pubmed:pagination |
361-73
|
|
pubmed:dateRevised |
2008-11-21
|
|
pubmed:meshHeading |
pubmed-meshheading:7823034-Amino Acid Sequence,
pubmed-meshheading:7823034-Animals,
pubmed-meshheading:7823034-Antiporters,
pubmed-meshheading:7823034-Base Sequence,
pubmed-meshheading:7823034-Biological Transport, Active,
pubmed-meshheading:7823034-DNA Primers,
pubmed-meshheading:7823034-Digestive System Physiological Phenomena,
pubmed-meshheading:7823034-Humans,
pubmed-meshheading:7823034-Hydrogen,
pubmed-meshheading:7823034-Manduca,
pubmed-meshheading:7823034-Models, Biological,
pubmed-meshheading:7823034-Molecular Sequence Data,
pubmed-meshheading:7823034-Polymerase Chain Reaction,
pubmed-meshheading:7823034-Potassium,
pubmed-meshheading:7823034-Potassium-Hydrogen Antiporters,
pubmed-meshheading:7823034-Sequence Homology, Amino Acid,
pubmed-meshheading:7823034-Sodium-Hydrogen Antiporter,
pubmed-meshheading:7823034-Sodium-Potassium-Exchanging ATPase
|
|
pubmed:year |
1994
|
|
pubmed:articleTitle |
K+/H+ antiport in the tobacco hornworm midgut: the K(+)-transporting component of the K+ pump.
|
|
pubmed:affiliation |
Zoologisches Institut der Universität, München, Germany.
|
|
pubmed:publicationType |
Journal Article,
Comparative Study,
Research Support, U.S. Gov't, P.H.S.,
Review,
Research Support, Non-U.S. Gov't
|
