Linked Life Data

10799514

Source:http://linkedlifedata.com/resource/pubmed/id/10799514

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
19
pubmed:dateCreated
2000-6-8
pubmed:abstractText
Eukaryotic cells contain various types of proteasomes. Core 20 S proteasomes (abbreviated 20 S below) have two binding sites for the regulatory particles, PA700 and PA28. PA700-20 S-PA700 complexes are known as 26 S proteasomes and are ATP-dependent machines that degrade cell proteins. PA28 is found both in previously described complexes of the type PA28-20 S-PA28 and in complexes that also contain PA700, as PA700-20 S-PA28. We refer to the latter as "hybrid proteasomes." The relative amounts of the various types of proteasomes in HeLa extracts were determined by a combination of immunoprecipitation and immunoblotting. Hybrid proteasomes accounted for about a fourth of all proteasomes in the extracts. Association of PA28 and proteasomes proved to be ATP-dependent. Hybrid proteasomes catalyzed ATP-dependent degradation of ornithine decarboxylase (ODC) without ubiquitinylation, as do 26 S proteasomes. In contrast, the homo-PA28 complex (PA28-20 S-PA28) was incapable of degrading ODC. Intriguingly, a major immunomodulatory cytokine, interferon-gamma, appreciably enhanced the ODC degradation in HeLa and SW620 cells through induction of the hybrid proteasome, which may also be responsible for the immunological processing of intracellular antigens. Taken together, we report here for the first time the existence of two types of ATP-dependent proteases, the 26 S proteasome and the hybrid proteasome, which appear to share the ATP-dependent proteolytic pathway in mammalian cells.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
12
pubmed:volume
275
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
14336-45
pubmed:dateRevised
2011-1-7
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Hybrid proteasomes. Induction by interferon-gamma and contribution to ATP-dependent proteolysis.
pubmed:affiliation
Tokyo Metropolitan Institute of Medical Science and Core Rsearch for Evolutional Science and Technology, Japan Science and Technology Corporation, 3-18-22 Honkomagome, Bunkyo-ku, Tokyo 113-8613, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't