Linked Life Data

8848168

Source:http://linkedlifedata.com/resource/pubmed/id/8848168

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1996-10-23
pubmed:abstractText
We have examined whether p21Ras proteins can rescue nerve growth factor-deprived rat sympathetic neurons from death, to test further our hypothesis that p21Ras is a central mediator in the nerve growth factor-to-survival signalling pathway. After crosslinking [125I]nerve growth factor to live neurons, two forms of Trk (molecular weight approximately 140,000 and 115,000) were immunoprecipitated with anti-Trk antibodies. Nerve growth factor induced tyrosine phosphorylation of both Trk forms and at least two additional proteins. When these phosphorylations were prevented by staurosporine (in a protein kinase C-independent manner) the neurons died. However, neurons were rescued from death due to staurosporine treatment by intracellular loading of oncogenic Ha-Ras(val12) protein. Both Ha-Ras(val12) and cellular Ha-Ras proteins maintained survival for several days in the absence of nerve growth factor and mimicked other actions of nerve growth factor, inducing rapid c-Fos protein expression and robust neurite outgrowth. Conversely, Fab fragments of neutralizing antibodies to p21Ras which blocked the capacity of nerve growth factor to promote neuron survival were also found to inhibit the early expression of c-Fos protein in these neurons. The close correspondence observed between the timing of onset of c-Fos responsiveness and acquisition of nerve growth factor-dependence in embryonic day 17 sympathetic neurons, and the coordinate increase found in both parameters until embryonic day 19 indicates that c-Fos protein expression is a good biochemical indicator of the presence of a functional nerve growth factor-to-survival signal transduction pathway. Nevertheless, expression of c-Fos is not sufficient for survival since phorbol esters induce c-Fos with no effect on survival. These data strengthen our proposal that p21Ras proteins are crucial anti-apoptotic mediators of survival in rat sympathetic neurons by demonstrating that p21Ras is both necessary and sufficient to rescue neurons which are disabled from signalling through Trk receptors.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0306-4522
pubmed:author
pubmed:issnType
Print
pubmed:volume
70
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1067-79
pubmed:dateRevised
2009-9-29
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Active p21Ras is sufficient for rescue of NGF-dependent rat sympathetic neurons.
pubmed:affiliation
Department of Human Anatomy, University of Oxford, U.K.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't