Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
46
pubmed:dateCreated
1996-1-17
pubmed:abstractText
Hepatocytes must transport newly synthesized apical membrane proteins from the basolateral to the apical plasma membrane. Our earlier morphological study showed that the apical proteins share a late (subapical) part of the transcytotic pathway with the well characterized polymeric immunoglobulin A receptor (Barr, V. A., and Hubbard, A. L. (1993) Gastroenterology 105, 554-571). Starting with crude microsomes from the livers of [35S]methionine-labeled rats, we sequentially immunoadsorbed first vesicles containing the endocytic asialoglycoprotein receptor and then (from the depleted supernatant) vesicles containing the polymeric IgA receptor. Biochemical characterization indicated that early basolateral and late endosomes were present in the first population but not in the second. Neither Golgi-, apical plasma membrane (PM)-, nor basolateral PM-derived vesicles were significant contaminants of either population. Both vesicle populations contained 35S-labeled receptor and 35S-labeled-dipeptidyl peptidase IV. Importantly, the elevated relative specific activity of the dipeptidyl peptidase (% of 35S-labeled/% immunoblotted) in the second population indicated that these vesicles must transport newly synthesized dipeptidyl peptidase IV. A distinct kind of vesicle was immunoadsorbed from a "carrier-vesicle fraction"; surprisingly, these vesicles contained little 35S-receptor and virtually no dipeptidyl peptidase IV. These results, together with previous kinetic data from in vivo experiments, are consistent with a computer-generated model predicting that newly synthesized dipeptidyl peptidase IV is delivered to basolateral endosomes, which also contain newly synthesized polymeric immunoglobulin A receptor. The two proteins are then transcytosed together to the subapical region.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
17
pubmed:volume
270
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
27834-44
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed-meshheading:7499255-Animals, pubmed-meshheading:7499255-Asialoglycoprotein Receptor, pubmed-meshheading:7499255-Asialoglycoproteins, pubmed-meshheading:7499255-Cell Fractionation, pubmed-meshheading:7499255-Cycloheximide, pubmed-meshheading:7499255-Dipeptidyl Peptidase 4, pubmed-meshheading:7499255-Endocytosis, pubmed-meshheading:7499255-Immunoglobulin A, pubmed-meshheading:7499255-Immunosorbent Techniques, pubmed-meshheading:7499255-Kinetics, pubmed-meshheading:7499255-Male, pubmed-meshheading:7499255-Methionine, pubmed-meshheading:7499255-Microsomes, Liver, pubmed-meshheading:7499255-Models, Biological, pubmed-meshheading:7499255-Organelles, pubmed-meshheading:7499255-Protein Synthesis Inhibitors, pubmed-meshheading:7499255-Rats, pubmed-meshheading:7499255-Rats, Sprague-Dawley, pubmed-meshheading:7499255-Receptors, Cell Surface, pubmed-meshheading:7499255-Receptors, Fc, pubmed-meshheading:7499255-Subcellular Fractions, pubmed-meshheading:7499255-Sulfur Radioisotopes, pubmed-meshheading:7499255-Time Factors
pubmed:year
1995
pubmed:articleTitle
Immunoadsorption of hepatic vesicles carrying newly synthesized dipeptidyl peptidase IV and polymeric IgA receptor.
pubmed:affiliation
Diabetes Branch, National Institutes of Health, Bethesda, Maryland 20892, USA.
pubmed:publicationType
Journal Article