Linked Life Data

19309463

Source:http://linkedlifedata.com/resource/pubmed/id/19309463

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2009-7-2
pubmed:abstractText
During leaf senescence, resources are recycled by redistribution to younger leaves and reproductive organs. Candidate pathways for the regulation of onset and progression of leaf senescence include ubiquitin-dependent turnover of key proteins. Here, we identified a novel plant U-box E3 ubiquitin ligase that prevents premature senescence in Arabidopsis plants, and named it SENESCENCE-ASSOCIATED E3 UBIQUITIN LIGASE 1 (SAUL1). Using in vitro ubiquitination assays, we show that SAUL1 has E3 ubiquitin ligase activity. We isolated two alleles of saul1 mutants that show premature senescence under low light conditions. The visible yellowing of leaves is accompanied by reduced chlorophyll content, decreased photochemical efficiency of photosystem II and increased expression of senescence genes. In addition, saul1 mutants exhibit enhanced abscisic acid (ABA) biosynthesis. We show that application of ABA to Arabidopsis is sufficient to trigger leaf senescence, and that this response is abolished in the ABA-insensitive mutants abi1-1 and abi2-1, but enhanced in the ABA-hypersensitive mutant era1-3. We found that increased ABA levels coincide with enhanced activity of Arabidopsis aldehyde oxidase 3 (AAO3) and accumulation of AAO3 protein in saul1 mutants. Using label transfer experiments, we showed that interactions between SAUL1 and AAO3 occur. This suggests that SAUL1 participates in targeting AAO3 for ubiquitin-dependent degradation via the 26S proteasome to prevent premature senescence.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
1365-313X
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
59
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
39-51
pubmed:dateRevised
2010-4-21
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Identification of a novel E3 ubiquitin ligase that is required for suppression of premature senescence in Arabidopsis.
pubmed:affiliation
Molekulare Pflanzenphysiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstrasse 5, D-91058 Erlangen, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't