Linked Life Data

10194759

Source:http://linkedlifedata.com/resource/pubmed/id/10194759

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1999-5-27
pubmed:abstractText
Sorting of the prohormone POMC to the regulated secretory pathway necessitates the binding of a sorting signal to a sorting receptor, identified as membrane carboxypeptidase E (CPE). The sorting signal, located at the N terminus of POMC consists of two acidic (Asp10, Glu14) and two hydrophobic (Leu11, Leu18) residues exposed on the surface of an amphipathic loop. In this study, molecular modeling of CPE predicted that the acidic residues in the POMC-sorting signal bind specifically to two basic residues, Arg255 and Lys260, present in a loop unique to CPE, compared with other carboxypeptidases. To test the model, these two residues on CPE were mutated to Ser or Ala, followed by baculovirus expression of the mutant CPEs in Sf9 cells. Sf9 cell membranes containing CPE mutants with either Arg255 or Lys260, or both residues substituted, showed no binding of [125I]N-POMC1-26 (which contains the POMC-sorting signal motif), proinsulin, or proenkephalin. In contrast, substitution of an Arg147 to Ala147 at a substrate-binding site, Arg259 to Ala259 and Ser202 to Pro202, in CPE did not affect the level of [125I]N-POMC1-26 binding when compared with-wild type CPE. Furthermore, mutation of the POMC-sorting signal motif (Asp10, Leu11, Glu14, Leu18) eliminated binding to wild-type CPE. These results indicate that the sorting signal of POMC, proinsulin, and proenkephalin specifically interacts with Arg255 and Lys260 at a novel binding site, independent of the active site on CPE.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0888-8809
pubmed:author
pubmed:issnType
Print
pubmed:volume
13
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
527-36
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed-meshheading:10194759-Animals, pubmed-meshheading:10194759-Arginine, pubmed-meshheading:10194759-Baculoviridae, pubmed-meshheading:10194759-Binding Sites, pubmed-meshheading:10194759-Carboxypeptidase H, pubmed-meshheading:10194759-Carboxypeptidases, pubmed-meshheading:10194759-Cell Membrane, pubmed-meshheading:10194759-Enkephalins, pubmed-meshheading:10194759-Insects, pubmed-meshheading:10194759-Lysine, pubmed-meshheading:10194759-Models, Molecular, pubmed-meshheading:10194759-Mutagenesis, Site-Directed, pubmed-meshheading:10194759-Mutation, pubmed-meshheading:10194759-Peptide Fragments, pubmed-meshheading:10194759-Pro-Opiomelanocortin, pubmed-meshheading:10194759-Proinsulin, pubmed-meshheading:10194759-Protein Conformation, pubmed-meshheading:10194759-Protein Precursors, pubmed-meshheading:10194759-Recombinant Proteins, pubmed-meshheading:10194759-Signal Transduction
pubmed:year
1999
pubmed:articleTitle
Identification of a novel prohormone sorting signal-binding site on carboxypeptidase E, a regulated secretory pathway-sorting receptor.
pubmed:affiliation
Section on Cellular Neurobiology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA.
pubmed:publicationType
Journal Article