Linked Life Data

11588168

Source:http://linkedlifedata.com/resource/pubmed/id/11588168

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
20
pubmed:dateCreated
2001-10-5
pubmed:abstractText
Synapsins are major neuronal phosphoproteins involved in regulation of neurotransmitter release. Synapsins are well established targets for multiple protein kinases within the nerve terminal, yet little is known about dephosphorylation processes involved in regulation of synapsin function. Here, we observed a reciprocal relationship in the phosphorylation-dephosphorylation of the established phosphorylation sites on synapsin I. We demonstrate that, in vitro, phosphorylation sites 1, 2, and 3 of synapsin I (P-site 1 phosphorylated by cAMP-dependent protein kinase; P-sites 2 and 3 phosphorylated by Ca(2+)-calmodulin-dependent protein kinase II) were excellent substrates for protein phosphatase 2A, whereas P-sites 4, 5, and 6 (phosphorylated by mitogen-activated protein kinase) were efficiently dephosphorylated only by Ca(2+)-calmodulin-dependent protein phosphatase 2B-calcineurin. In isolated nerve terminals, rapid changes in synapsin I phosphorylation were observed after Ca(2+) entry, namely, a Ca(2+)-dependent phosphorylation of P-sites 1, 2, and 3 and a Ca(2+)-dependent dephosphorylation of P-sites 4, 5, and 6. Inhibition of calcineurin activity by cyclosporin A resulted in a complete block of Ca(2+)-dependent dephosphorylation of P-sites 4, 5, and 6 and correlated with a prominent increase in ionomycin-evoked glutamate release. These two opposing, rapid, Ca(2+)-dependent processes may play a crucial role in the modulation of synaptic vesicle trafficking within the presynaptic terminal.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
1529-2401
pubmed:author
pubmed:issnType
Electronic
pubmed:day
15
pubmed:volume
21
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
7944-53
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Opposing changes in phosphorylation of specific sites in synapsin I during Ca2+-dependent glutamate release in isolated nerve terminals.
pubmed:affiliation
Laboratory of Molecular and Cellular Neuroscience, The Rockefeller University, New York, New York 10021, USA. j.jovanovic@ucl.ac.uk
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't