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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
14
pubmed:dateCreated
2000-5-8
pubmed:abstractText
By forming a molecular tether between two membranes, p115, giantin, and GM130 may mediate multiple Golgi-related processes including vesicle transport, cisternae formation, and cisternal stacking. The tether is proposed to involve the simultaneous binding of p115 to giantin on one membrane and to GM130 on another membrane. To explore this model, we tested for the presence of the putative giantin-p115-GM130 ternary complex. We first mapped p115-binding site in giantin to a 70-amino acid coiled-coil domain at the extreme N terminus, a position that may exist up to 400 nm away from the Golgi membrane. We then generated glutathione S-transferase (GST) fusion proteins containing either giantin's or GM130's p115 binding site and tested whether such proteins could bind p115 and GM130 or bind p115 and giantin, respectively. Unexpectedly, GST fusions containing either the giantin or the GM130 p115 binding site efficiently bound p115, but the p115 bound to GST-giantin did not bind GM130, and the p115 bound to GST-GM130 did not bind giantin. To explain this result, we mapped the giantin binding site in p115 and found that it is located at the C-terminal acidic domain, the same domain involved in binding GM130. The presence of a single binding site in p115 for giantin and GM130 was confirmed by demonstration that giantin and GM130 compete for binding to p115. These results question a simple tethering model involving a ternary giantin-p115-GM130 complex and suggest that p115-giantin and p115-GM130 interactions might mediate independent membrane tethering events.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
7
pubmed:volume
275
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
10196-201
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:10744704-Amino Acid Sequence, pubmed-meshheading:10744704-Animals, pubmed-meshheading:10744704-Autoantigens, pubmed-meshheading:10744704-Binding Sites, pubmed-meshheading:10744704-Carrier Proteins, pubmed-meshheading:10744704-Cell Line, pubmed-meshheading:10744704-Cloning, Molecular, pubmed-meshheading:10744704-Escherichia coli, pubmed-meshheading:10744704-Golgi Apparatus, pubmed-meshheading:10744704-Kidney, pubmed-meshheading:10744704-Membrane Fusion, pubmed-meshheading:10744704-Membrane Proteins, pubmed-meshheading:10744704-Molecular Sequence Data, pubmed-meshheading:10744704-Peptide Fragments, pubmed-meshheading:10744704-Protein Binding, pubmed-meshheading:10744704-Rats, pubmed-meshheading:10744704-Recombinant Fusion Proteins, pubmed-meshheading:10744704-Restriction Mapping, pubmed-meshheading:10744704-Vesicular Transport Proteins
pubmed:year
2000
pubmed:articleTitle
Binding relationships of membrane tethering components. The giantin N terminus and the GM130 N terminus compete for binding to the p115 C terminus.
pubmed:affiliation
Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA. linstedt@andrew.cmu.edu
pubmed:publicationType
Journal Article