Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1994-2-28
pubmed:abstractText
Src-homology region 2 (SH2) domains are stretches of about 100 amino acids which are found to be structurally conserved in a number of signaling molecules. These regions have been shown to bind with high affinity to phosphotyrosine residues within activated receptor tyrosine kinases. Here we report the bacterial expression and purification of individual N-terminal SH2 (NSH2) domains of phosphatidylinositol 3-kinase (PI-3K) binding subunit (p85) and Ras GTPase activating protein (GAP) in amounts suitable for structure-function studies. The p85NSH2 domain stains dark purple and absorbs around 620-640 nm with Stains-all, a dye known to bind to calcium binding proteins. This effect was not observed for the GAPNSH2 domain. Circular dichroism analysis of the N-terminal SH2 domain of these proteins shows that p85NSH2, but not GAPNSH2, undergoes a significant dose-dependent change in conformation in the presence of increasing calcium concentrations. Moreover, the conformational change of p85NSH2 induced by calcium could be replicated by addition of a phosphorylated hexapeptide (DYpMDMK) representing the alpha-PDGFR binding site for p85. Limited proteolysis studies showed a significant calcium-dependent increase in protection of p85NSH2 but not GAPNSH2 from degradation by subtilisin. Our results further indicate that holmium, a trivalent lanthanide ion, which has been previously shown to substitute for calcium, could also protect the p85NSH2 domain from proteolysis even at 10-fold lower concentrations. In vitro binding studies using purified preparations of activated alpha-PDGFR show that calcium did not affect the binding of GAPNSH2 domains to activated alpha-PDGFR.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Calcium, http://linkedlifedata.com/resource/pubmed/chemical/Carbocyanines, http://linkedlifedata.com/resource/pubmed/chemical/GTPase-Activating Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Oligopeptides, http://linkedlifedata.com/resource/pubmed/chemical/Oncogene Protein pp60(v-src), http://linkedlifedata.com/resource/pubmed/chemical/Peptide Fragments, http://linkedlifedata.com/resource/pubmed/chemical/Phosphatidylinositol 3-Kinases, http://linkedlifedata.com/resource/pubmed/chemical/Phosphotransferases (Alcohol Group..., http://linkedlifedata.com/resource/pubmed/chemical/Platelet-Derived Growth Factor, http://linkedlifedata.com/resource/pubmed/chemical/Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Recombinant Proteins, http://linkedlifedata.com/resource/pubmed/chemical/ras GTPase-Activating Proteins, http://linkedlifedata.com/resource/pubmed/chemical/stains-all
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
33
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
746-54
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed-meshheading:8292602-Amino Acid Sequence, pubmed-meshheading:8292602-Calcium, pubmed-meshheading:8292602-Carbocyanines, pubmed-meshheading:8292602-Circular Dichroism, pubmed-meshheading:8292602-Dose-Response Relationship, Drug, pubmed-meshheading:8292602-GTPase-Activating Proteins, pubmed-meshheading:8292602-Models, Chemical, pubmed-meshheading:8292602-Molecular Sequence Data, pubmed-meshheading:8292602-Oligopeptides, pubmed-meshheading:8292602-Oncogene Protein pp60(v-src), pubmed-meshheading:8292602-Peptide Fragments, pubmed-meshheading:8292602-Phosphatidylinositol 3-Kinases, pubmed-meshheading:8292602-Phosphotransferases (Alcohol Group Acceptor), pubmed-meshheading:8292602-Platelet-Derived Growth Factor, pubmed-meshheading:8292602-Protein Biosynthesis, pubmed-meshheading:8292602-Protein Conformation, pubmed-meshheading:8292602-Proteins, pubmed-meshheading:8292602-Recombinant Proteins, pubmed-meshheading:8292602-Sequence Homology, Amino Acid, pubmed-meshheading:8292602-Signal Transduction, pubmed-meshheading:8292602-Spectrophotometry, Ultraviolet, pubmed-meshheading:8292602-ras GTPase-Activating Proteins
pubmed:year
1994
pubmed:articleTitle
Comparison of calcium-dependent conformational changes in the N-terminal SH2 domains of p85 and GAP defines distinct properties for SH2 domains.
pubmed:affiliation
Macromolecular Structure Laboratory, NCI-FCDRC, ABL-Basic Research Program, Frederick, Maryland 21702.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S.