Linked Life Data

8757605

Source:http://linkedlifedata.com/resource/pubmed/id/8757605

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1996-9-26
pubmed:abstractText
Evidence suggests that peptide loading onto MHC class II molecules occurs in a specialized late endocytic compartment (MIIC) where HLA-DM predominantly resides and in which MHC class II transiently accumulates before transport to the cell surface. We examined the targeting signals and compartments involved in the intracellular trafficking of human HLA-DM by expressing hybrid molecules comprising the cytoplasmic domain of DMB and luminal and transmembrane domains of CD8 in HeLa cells. A tyrosine-based tetrapeptide motif present in the cytoplasmic domain of DMB targeted hybrid molecules to intracellular vesicles. Mutation of the tyrosine residue to alanine resulted in redistribution of hybrid molecules to the cell surface. Correct intracellular targeting of HLA-DM was crucial for normal function in B cells. Immunoelectron microscopy on ultrathin cryosections showed that CD8-DMB molecules accumulated in late endocytic compartments sharing characteristics with lysosomes, like MHC class II compartments in APCs. Thus far, the exit of DMB from the Golgi complex has not been elucidated. Interestingly, we found that although the mannose 6-phosphate receptor and CD8-DMB contain similar tyrosine signals, no co-localization was observed in the trans-Golgi network, suggesting that these proteins are differentially sorted at this site. Co-transfection of CD8-DMB, HLA-DR alpha, HLA-DR beta, and an invariant chain revealed that HLA-DR molecules accumulated together with CD8-DMB in these lysosomal compartments. The similarity of these lysosomal-like compartments in wild-type and transfected cells suggests that they are part of the normal endocytic pathway in non-APCs.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0022-1767
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
157
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1017-27
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Targeting signal and subcellular compartments involved in the intracellular trafficking of HLA-DMB.
pubmed:affiliation
Renal Laboratories, United Medical and Dental Schools, Guy's Campus, London, United Kingdom.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't