Linked Life Data

9119074

Source:http://linkedlifedata.com/resource/pubmed/id/9119074

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2-3
pubmed:dateCreated
1997-4-18
pubmed:abstractText
Recently, we have reported the isolation and purification of 20S proteasomes from both the procyclic and bloodstream forms of Trypanosoma brucei, but no 26S proteasome was identified under those experimental conditions (Hua et al., Mol. Biochem. Parasitol. (1996) 78, 33-46). Subsequent attempts to identify a 26S proteasome in T. brucei led to the discovery of another form of the 20S proteasome designated the activated 20S proteasome because it exhibited much higher peptidase activities than the original 20S proteasome on all the fluorogenic peptides tested, and it crossreacted with the rabbit antisera against the 20S proteasomes purified from T. brucei. The activated 20S proteasome can be isolated from both procyclic and bloodstream forms of T. brucei and has a slightly higher molecular weight than the 20S proteasome. It is stable in the absence of ATP but susceptible to elution through a DE52 column. Analysis of the activated 20S proteasome in SDS-PAGE showed the presence of all the subunit proteins from the 20S proteasome plus an extra protein with an estimated molecular mass of 26 kDa. This protein, designated PA26, is not a degradation product of the 20S proteasomal subunit proteins. It could be a homolog of the bovine PA28 and human 11S regulator protein which form complexes with the 20S proteasomes resulting in activation of their peptidase activities. This likelihood was confirmed in a reconstitution experiment in which PA26 separated from the proteasome by a DE52 column chromatography was re-introduced into the purified 20S proteasome, and resulted in the emergence of a new protein band with the same mobility and peptidase activities as the activated 20S proteasome in native polyacrylamide gel electrophoresis. The presence of an activated 20S proteasome rather than a homolog of the 26S proteasome in T. brucei suggests that PA26 may play an important role in regulating the proteasome-mediated protein degradations in trypanosomes.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0014-5793
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
404
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
253-62
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:9119074-Adenosine Triphosphate, pubmed-meshheading:9119074-Animals, pubmed-meshheading:9119074-Blood Cells, pubmed-meshheading:9119074-Cattle, pubmed-meshheading:9119074-Chromatography, DEAE-Cellulose, pubmed-meshheading:9119074-Cross Reactions, pubmed-meshheading:9119074-Cysteine Endopeptidases, pubmed-meshheading:9119074-Electrophoresis, Polyacrylamide Gel, pubmed-meshheading:9119074-Enzyme Activation, pubmed-meshheading:9119074-Humans, pubmed-meshheading:9119074-Immune Sera, pubmed-meshheading:9119074-Immunoblotting, pubmed-meshheading:9119074-Molecular Weight, pubmed-meshheading:9119074-Multienzyme Complexes, pubmed-meshheading:9119074-Proteasome Endopeptidase Complex, pubmed-meshheading:9119074-Rabbits, pubmed-meshheading:9119074-Rats, pubmed-meshheading:9119074-Rats, Sprague-Dawley, pubmed-meshheading:9119074-Substrate Specificity, pubmed-meshheading:9119074-Trypanosoma brucei brucei, pubmed-meshheading:9119074-Trypanosomiasis, African
pubmed:year
1997
pubmed:articleTitle
Identification and characterization of an activated 20S proteasome in Trypanosoma brucei.
pubmed:affiliation
Department of Pharmaceutical Chemistry, University of California San Francisco, 94143-0446, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.