Linked Life Data

6134785

Source:http://linkedlifedata.com/resource/pubmed/id/6134785

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1983-8-11
pubmed:abstractText
We report here characterization of calmodulin-stimulated Ca2+ transport activities in synaptic plasma membranes (SPM). The calcium transport activity consists of a Ca2+-stimulated, Mg2+-dependent ATP hydrolysis coupled with ATP-dependent Ca2+ uptake into membraneous sacs on the cytosolic face of the synaptosomal membrane. These transport activities have been found in synaptosomal subfractions to be located primarily in SPM-1 and SPM-2. Both Ca2+-ATPase and ATP-dependent Ca2+ uptake require calmodulin for maximal activity (KCm for ATPase = 60 nM; KCm for uptake = 50 nM). In the reconstituted membrane system, KCa was found to be 0.8 microM for Ca2+-ATPase and 0.4 microM for Ca2+ uptake. These results demonstrate for the first time the calmodulin requirements for the Ca2+ pump in SPM when Ca2+ ATPase and Ca2+ uptake are assayed under functionally coupled conditions. They suggest that calmodulin association with the membrane calcium pump is regulated by the level of free Ca2+ in the cytoplasm. The activation by calmodulin, in turn, regulates the cytosolic Ca2+ levels in a feedback process. These studies expand the calmodulin hypothesis of synaptic transmission to include activation of a high-affinity Ca2+ + Mg2+ ATPase as a regulator for cytosolic Ca2+.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0022-3042
pubmed:author
pubmed:issnType
Print
pubmed:volume
41
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
161-71
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
1983
pubmed:articleTitle
Calmodulin stimulation of Ca2+-dependent ATP hydrolysis and ATP-dependent Ca2+ transport in synaptic membranes.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.