Linked Life Data

12728008

Source:http://linkedlifedata.com/resource/pubmed/id/12728008

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
Pt 11
pubmed:dateCreated
2003-5-2
pubmed:abstractText
Secretory activity in blowfly salivary glands is activated by the hormone serotonin. We have investigated the distribution and activity of two cation pumps that are possibly involved with transepithelial ion transport, i.e. Na(+)/K(+)-ATPase and vacuolar-type H(+)-ATPase (V-ATPase). By immunofluorescence labelling of secretory cells, Na(+)/K(+)-ATPase was localized on the basolateral plasma membrane and V-ATPase on the highly folded apical membrane. Activities of both ATPases were probed in salivary gland homogenates by applying specific inhibitors for these ion pumps, namely ouabain and bafilomycin A(1). In control glands, bafilomycin-A(1)-sensitive V-ATPase activity and ouabain-sensitive Na(+)/K(+)-ATPase activity accounted for 36% and 19%, respectively, of the total ATPase activity. V-ATPase activity increased approximately twofold after stimulation with serotonin, whereas Na(+)/K(+)-ATPase activity was not significantly affected. Biochemical assays provided evidence that the serotonin-induced activation of V-ATPase activity was accompanied by a recruitment of peripheral V(1) subunits from the cytosol to the plasma membrane, indicative of the assembly of V(0)V(1) holoenzymes. These data show that a V-ATPase located in the apical plasma membranes of the secretory cells is a component of the apical "potassium pump" that has been identified previously by physiological approaches. The V-ATPase energizes the apical membrane and provides the primary driving force for fuelling a putative K(+)/nH(+) antiporter and, thus, for fluid secretion. Serotonin-induced assembly of V(0)V(1) holoenzymes might constitute a regulatory mechanism for the control of pump activity.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0022-0949
pubmed:author
pubmed:issnType
Print
pubmed:volume
206
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1867-76
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Distribution and serotonin-induced activation of vacuolar-type H+-ATPase in the salivary glands of the blowfly Calliphora vicina.
pubmed:affiliation
Institut für Biochemie und Biologie, Zoophysiologie, Universität Potsdam, Lennéstrasse 7a, D-14471 Potsdam, Germany.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't