Linked Life Data

2540710

Source:http://linkedlifedata.com/resource/pubmed/id/2540710

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1989-6-7
pubmed:abstractText
The localization, expression, and transport of two lysosomal integral membrane glycoproteins of human cells, hLAMP-1 and hLAMP-2, have been studied in mucolipidosis II (I-cell disease) fibroblasts. These cells are deficient in N-acetylglucosaminylphosphotransferase, one of the enzymes required for addition of the mannose 6-phosphate recognition signal to newly synthesized lysosomal hydrolases and a prerequisite for the sorting and transport of the hydrolases to lysosomes. I-cells analyzed by immunofluorescence microscopy with monoclonal antibodies against hLAMP-1 and hLAMP-2 showed intense staining of the inclusion bodies covering most of the cytoplasm of the cells. Immunoelectron microscopy confirmed this localization and showed that the hLAMP-positive vesicles commonly contained membrane structures or electron-dense homogeneous material characteristic of secondary lysosomes. Studies of the biosynthesis of hLAMP-2 in I-cells pulse-labeled with [35S]methionine indicated that the molecule is glycosylated in the Golgi system, is transported to vesicles with the high density characteristic of lysosomes, and has chemical properties similar to those of the glycoprotein synthesized in normal cells. The concentration of the hLAMP-2 glycoprotein was three- to fourfold greater than that in normal fibroblasts, in sharp contrast to the reduced levels of lysosomal hydrolases seen in I-cells. These experiments demonstrate that the inclusion bodies in I-cells have properties of secondary lysosomes and that the transport and targeting of the lysosomal membrane glycoproteins to the inclusion bodies of these cells is not coupled to the mannose 6-phosphate system for transporting soluble acid hydrolases.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0003-9861
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
271
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
157-67
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Lysosomal integral membrane glycoproteins are expressed at high levels in the inclusion bodies of I-cell disease fibroblasts.
pubmed:affiliation
Cell Biology and Metabolism Branch, National Institute of Child Health and Human Development, Bethesda, Maryland 20892.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.