Linked Life Data

9368009

Source:http://linkedlifedata.com/resource/pubmed/id/9368009

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
47
pubmed:dateCreated
1997-12-23
pubmed:abstractText
Thyroid peroxidase (TPO1) is a membrane-bound heme-containing glycoprotein that catalyzes the synthesis of thyroid hormones. We generated stable cell lines expressing TPO1 and the alternatively spliced isoform TPO2. Pulse-chase studies showed that TPO2 half-life was dramatically decreased as compared with TPO1. The sensitivity of TPO2 to endo-beta-N-acetylglucosaminidase H indicated that the protein is processed through the endoplasmic reticulum and bears high mannose-type structures. Cell surface biotinylation experiments showed that the two isoforms also differ in their intracellular trafficking. TPO2 was totally retained in the cell, whereas 15% of TPO1 reached the cell surface. The inability of TPO2 to come out of the intracellular compartments was related to structural changes in the molecule. Evidence of these changes was obtained through the lack of recognition of TPO2 by half of the 13 TPO monoclonal antibodies tested in immunoprecipitation experiments. Our data suggest that because of an improper folding, TPO2 is trapped in the endoplasmic reticulum and rapidly degraded. The failure of incorporation of [14C]aminolevulinic acid in the cultured cells showed that TPO2 did not bind to heme, whereas TPO1 did. This result was confirmed through a guaiacol assay showing that TPO2 is enzymatically inactive.
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
21
pubmed:volume
272
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
29487-92
pubmed:dateRevised
2005-11-17
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Human thyroperoxidase in its alternatively spliced form (TPO2) is enzymatically inactive and exhibits changes in intracellular processing and trafficking.
pubmed:affiliation
INSERM U38, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille, cedex 05, France.
pubmed:publicationType
Journal Article