Linked Life Data

3856614

Source:http://linkedlifedata.com/resource/pubmed/id/3856614

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1985-5-23
pubmed:abstractText
We have sought to understand the role of the electrophoretically invariant chain (Ii) in class II antigen functions, particularly in certain transformed cells in which we have previously demonstrated hyperexpression of Ii. Molecular structures and relative kinetics of Ii synthesis, processing and turnover were compared in paired, Ia+ and Ia- Burkitt's lymphoma (BL) cell lines and in hairy cell leukemia (HCL) cells. Cells were metabolically labeled with [35S] methionine for 15 min (with or without a cold methionine chase to 3 hr) or were continuously labeled for 3 hr. One- and two-dimensional gel electrophoresis resolved immunoprecipitates formed with a) a heteroantiserum to purified class II antigen (demonstrating alpha and beta chains and Ii associated with that complex), b) a heteroantiserum to hairy cell leukemia (HCL) membranes (demonstrating principally the dominant, basic form of Ii molecules, class I antigens, and some additional proteins), and c) a monoclonal antibody to human Ii. Treatment of Ia+ Jijoye and its daughter, Ia- P3HR-1, BL cells with 4 mM butyrate for 48 hr enhanced the synthesis of the dominant, basic form of Ii but did not affect apparent turnover rates of that pool of Ii chains in either cell line. In Ia+ Jijoye cells but not in Ia- P3HR-1 cells Ii was terminally processed to more acidic, sialic acid-derivatized forms. Butyrate treatment did not alter the relative turnover rate of terminally processed Ii in Jijoye cells. The level of the dominant, basic form of Ii in HCL cells equaled that in butyrate-treated Jijoye cells, and relative turnover rates of this terminally unprocessed Ii pool were similar in HCL and Jijoye cells. However, HCL Ia-associated Ii was not terminally processed, as was Ia-associated Ii in Jijoye cells. The expression of Ia auxiliary proteins, p41 and p25, was also enhanced in Jijoye cells by butyrate treatment and was prominent in HCL cells. From these experiments, we may hypothesize the following. In lymphoblastoid cells, two pathways for Ii turnover could exist. One is through association with Ia complexes and progressive terminal processing of carbohydrate side chains and a second is not associated with Ia or, apparently, with such processing. Because Ii is not found to be terminally processed in the absence of class II antigen, Ia might be considered to direct the processing of a subset of Ii towards some function (rather than vice versa).(ABSTRACT TRUNCATED AT 400 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0022-1767
pubmed:author
pubmed:issnType
Print
pubmed:volume
134
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3539-49
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1985
pubmed:articleTitle
Kinetics of Ii synthesis, processing, and turnover in n-butyrate-treated Burkitt's lymphoma cell lines which express or do not express class II antigens and in hairy leukemic cells.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.