Linked Life Data

8799850

Source:http://linkedlifedata.com/resource/pubmed/id/8799850

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1997-2-28
pubmed:abstractText
When expressed in pituitary AtT-20 cells, parotid proline-rich proteins enter the regulated pathway. Because the short N-terminal domain of a basic proline-rich protein is necessary for efficient export from the ER, it has not been possible to evaluate the role of this polypeptide segment as a sorting signal for regulated secretion. We now show that addition of the six-amino acid propeptide of proparathyroid hormone to the proline-rich protein, and especially to a deletion mutant lacking the N-terminal domain, dramatically accelerates intracellular transport of these polypeptides. Under these conditions the chimeric deletion mutant is stored as effectively as the full-length protein in dense core granules. The propeptide does not function as a sorting signal in AtT-20 cells as it does not reroute a constitutively secreted reporter protein to the regulated pathway. During transit, the propeptide is cleaved from the chimeric polypeptides such that the original structures of the full-length and the deletion mutant proline-rich proteins are reestablished. We have also found that the percentage stimulated secretion of the proline-rich proteins increases incrementally (almost twofold) as their level of expression is elevated. The increase reflects an enrichment of these polypeptides in the granule pool and its incremental nature suggests that sorting of proline-rich proteins involves an aggregation-based process. Because we can now rule out contributions to sorting by both N- and C-terminal segments of the proline-rich protein, we deduce that the unique proline-rich domain is responsible for storage. Thus at least some of the determinants of sorting for regulated secretion are protein-specific rather than universal.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0021-9533
pubmed:author
pubmed:issnType
Print
pubmed:volume
109 ( Pt 6)
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1637-45
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:8799850-Animals, pubmed-meshheading:8799850-Binding Sites, pubmed-meshheading:8799850-Cell Line, pubmed-meshheading:8799850-Endoplasmic Reticulum, pubmed-meshheading:8799850-Membrane Glycoproteins, pubmed-meshheading:8799850-Mice, pubmed-meshheading:8799850-Molecular Structure, pubmed-meshheading:8799850-Mutagenesis, Site-Directed, pubmed-meshheading:8799850-Parathyroid Hormone, pubmed-meshheading:8799850-Parotid Gland, pubmed-meshheading:8799850-Peptides, pubmed-meshheading:8799850-Proline, pubmed-meshheading:8799850-Proline-Rich Protein Domains, pubmed-meshheading:8799850-Protein Precursors, pubmed-meshheading:8799850-Protein Processing, Post-Translational, pubmed-meshheading:8799850-Protein Sorting Signals, pubmed-meshheading:8799850-Recombinant Proteins, pubmed-meshheading:8799850-Transfection, pubmed-meshheading:8799850-Viral Envelope Proteins
pubmed:year
1996
pubmed:articleTitle
The unique proline-rich domain of parotid proline-rich proteins functions in secretory sorting.
pubmed:affiliation
Department of Cell Biology, University of Virginia Health Sciences Center, Charlottesville 22908, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.