Linked Life Data

7867640

Source:http://linkedlifedata.com/resource/pubmed/id/7867640

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1995-3-28
pubmed:abstractText
Proteasomes are high-molecular-mass multisubunit complexes which are believed, either by themselves or as a part of the 26S proteinase complex, to play a central role in extralysosomal pathways of intracellular protein breakdown. We have addressed the degradation of proteasomes in rat liver, investigating the possible role of lysosomes. Affinity-purified antibodies against rat liver proteasomes were used for immunoblot analysis of isolated lysosomes. Although proteasomes are not found in lysosomes from normally fed rats, they were found to accumulate in lysosomes of rats treated with leupeptin (an inhibitor of lysosomal proteases) and could also be detected in lysosomes isolated from livers of starved (24 h) rats. Proteinase-K treatment of these fractions, as well as immunogold procedures, show that a proportion of the proteasomes are inside lysosomes. Comparison of the amount of proteasomes found in lysosomes by immunoblotting with their experimentally determined half life (8.3 days) is consistent with an important role of these organelles in the degradation of rat liver proteasomes. Nevertheless, these data do not exclude the possibility that some nonlysosomal degradation of proteasome components also occurs. Since proteasomes were localized in autophagic vacuoles, it is likely that they are taken up mainly by nonselective autophagy. However, using an in vitro system, it was found that, under conditions of starvation, proteasomes may also be taken up into lysosomes and degraded via the heat-shock cognate protein of 73 kDa (hsc73)-mediated transport.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0014-2956
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
227
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
792-800
pubmed:dateRevised
2007-7-23
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Degradation of proteasomes by lysosomes in rat liver.
pubmed:affiliation
Instituto de Investigaciones Citológicas, Fundación Valenciana de Investigaciones Biomédicas, Spain.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't