Linked Life Data

10206996

Source:http://linkedlifedata.com/resource/pubmed/id/10206996

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
17
pubmed:dateCreated
1999-5-20
pubmed:abstractText
Nerve growth factor (NGF)-induced neurite outgrowth from rat PC12 cells was coincident with elevated (>/=2-fold) levels of endogenous ubiquitin (Ub) protein conjugates, elevated rates of formation of 125I-labeled Ub approximately E1 (Ub-activating enzyme) thiol esters and 125I-labeled Ub approximately E2 (Ub carrier protein) thiol esters in vitro, and enhanced capacity to synthesize 125I-labeled Ub-protein conjugates de novo. Activities of at least four E2s were increased in NGF-treated cells, including E2(14K), a component of the N-end rule pathway. Ubiquitylation of 125 I-labeled beta-lactoglobulin was up to 4-fold greater in supernatants from NGF-treated cells versus untreated cells and was selectively inhibited by the dipeptide Leu-Ala, an inhibitor of Ub isopeptide ligase (E3). However, Ub-dependent proteolysis of 125I-labeled beta-lactoglobulin was not increased in supernatants from NGF-treated cells, suggesting that neurite outgrowth is promoted by enhanced rates of synthesis (rather than degradation) of Ub-protein conjugates. Consistent with this observation, neurite outgrowth was induced by proteasome inhibitors (lactacystin and clasto-lactacystin beta-lactone) and was associated with elevated levels of ubiquitylated protein and stabilization of the Ub-dependent substrate, p53. Lactacystin-induced neurite outgrowth was blocked by the dipeptide Leu-Ala (2 mM) but not by His-Ala. These data 1) demonstrate that the enhanced pool of ubiquitylated protein observed during neuritogenesis in PC12 cells reflects coordinated up-regulation of Ub-conjugating activity, 2) suggest that Ub-dependent proteolysis is a negative regulator of neurite outgrowth in vitro, and 3) support a role for E2(14K)/E3-mediated protein ubiquitylation in PC12 cell neurite outgrowth.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
23
pubmed:volume
274
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
11789-95
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Neurite outgrowth in PC12 cells. Distinguishing the roles of ubiquitylation and ubiquitin-dependent proteolysis.
pubmed:affiliation
Laboratory for Nutrition and Vision Research, Jean Mayer United States Department of Agriculture-Human Nutrition Research Center on Aging at Tufts University, Boston, Massachusetts 02111, USA. Obin_c1@HNRC.tufts.edu
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.