Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6834
pubmed:dateCreated
2001-5-10
pubmed:databankReference
pubmed:abstractText
Small G proteins are GTP-dependent molecular switches that regulate numerous cellular functions. They can be classified into homologous subfamilies that are broadly associated with specific biological processes. Cross-talk between small G-protein families has an important role in signalling, but the mechanism by which it occurs is poorly understood. The coordinated action of Arf and Rho family GTPases is required to regulate many cellular processes including lipid signalling, cell motility and Golgi function. Arfaptin is a ubiquitously expressed protein implicated in mediating cross-talk between Rac (a member of the Rho family) and Arf small GTPases. Here we show that Arfaptin binds specifically to GTP-bound Arf1 and Arf6, but binds to Rac.GTP and Rac.GDP with similar affinities. The X-ray structure of Arfaptin reveals an elongated, crescent-shaped dimer of three-helix coiled-coils. Structures of Arfaptin with Rac bound to either GDP or the slowly hydrolysable analogue GMPPNP show that the switch regions adopt similar conformations in both complexes. Our data highlight fundamental differences between the molecular mechanisms of Rho and Ras family signalling, and suggest a model of Arfaptin-mediated synergy between the Arf and Rho family signalling pathways.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0028-0836
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
411
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
215-9
pubmed:dateRevised
2010-10-11
pubmed:meshHeading
pubmed-meshheading:11346801-ADP-Ribosylation Factor 1, pubmed-meshheading:11346801-ADP-Ribosylation Factors, pubmed-meshheading:11346801-Adaptor Proteins, Signal Transducing, pubmed-meshheading:11346801-Amino Acid Sequence, pubmed-meshheading:11346801-Binding, Competitive, pubmed-meshheading:11346801-Calorimetry, pubmed-meshheading:11346801-Carrier Proteins, pubmed-meshheading:11346801-Crystallography, X-Ray, pubmed-meshheading:11346801-Dimerization, pubmed-meshheading:11346801-Fluorescence Polarization, pubmed-meshheading:11346801-Guanosine Diphosphate, pubmed-meshheading:11346801-Guanosine Triphosphate, pubmed-meshheading:11346801-Guanylyl Imidodiphosphate, pubmed-meshheading:11346801-Humans, pubmed-meshheading:11346801-Models, Molecular, pubmed-meshheading:11346801-Molecular Sequence Data, pubmed-meshheading:11346801-Mutation, pubmed-meshheading:11346801-Protein Binding, pubmed-meshheading:11346801-Protein Conformation, pubmed-meshheading:11346801-Sequence Alignment, pubmed-meshheading:11346801-Signal Transduction, pubmed-meshheading:11346801-Temperature, pubmed-meshheading:11346801-Titrimetry, pubmed-meshheading:11346801-rac GTP-Binding Proteins
pubmed:year
2001
pubmed:articleTitle
The structural basis of Arfaptin-mediated cross-talk between Rac and Arf signalling pathways.
pubmed:affiliation
Division of Protein Structure, National Institute for Medical Research, Mill Hill, London NW7 IAA, UK.
pubmed:publicationType
Journal Article