Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2005-5-25
pubmed:abstractText
The cyclin-dependent kinase inhibitors (CKIs) bind to and directly regulate the catalytic activity of cyclin-dependent kinase (Cdk)/cyclin complexes involved in cell cycle control and do not regulate other, closely related Cdks. We showed previously that the CKI, p27, binds to Cdk2/cyclin A though a sequential mechanism that involves folding-on-binding. The first step in the kinetic mechanism is interaction of a small, highly dynamic domain of p27 (domain 1) with the cyclin subunit of the Cdk2/cyclin A complex, followed by much slower binding of a more lengthy and less flexible domain (domain 2) to Cdk2. The second step requires folding of domain 2 into the kinase inhibitory conformation. Rapid binding of p27 domain 1 to cyclin A tethers the inhibitor to the binary Cdk2/cyclin A complex, which reduces the entropic barrier associated with slow binding of domain 2 to the catalytic subunit. We show here that p27/cyclin interactions are an important determinant of p27 specificity towards cell cycle Cdks. We used surface plasmon resonance, limited proteolysis, mass spectrometry, and NMR spectroscopy to study the interaction of p27 with Cdk2/cyclin A, and with another Cdk complex, Cdk5/p25, that is involved in neurodegeneration. Importantly, Cdk5/p35 (the parent complex of Cdk5/p25) is not regulated by p27 in neurons. Our results show that p27 binds to Cdk5 and Cdk2 with similar, slow kinetics. However, p27 fails to interact with p25 within the Cdk5/p25 complex, which we believe prevents formation of a kinetically trapped, inhibited p27/Cdk5/p25 complex in vivo. The helical topology of p25 is very similar to that of cyclin A. However, p25 lacks the MRAIL sequence in one helix that, in the cell cycle cyclins, mediates specific interactions with domain 1 of p21 and p27. Our results strongly suggest that p21 and p27, related Cdk inhibitors, select their cell cycle regulatory Cdk targets by binding specifically to the cyclin subunit of these Cdk/cyclin complexes as a first step in a sequential, folding-on-binding mechanism.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/CDC2-CDC28 Kinases, http://linkedlifedata.com/resource/pubmed/chemical/CDK2 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/CDK5 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/Cell Cycle Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Cyclin A, http://linkedlifedata.com/resource/pubmed/chemical/Cyclin-Dependent Kinase 2, http://linkedlifedata.com/resource/pubmed/chemical/Cyclin-Dependent Kinase 5, http://linkedlifedata.com/resource/pubmed/chemical/Cyclin-Dependent Kinase Inhibitor..., http://linkedlifedata.com/resource/pubmed/chemical/Cyclin-Dependent Kinases, http://linkedlifedata.com/resource/pubmed/chemical/Peptide Hydrolases, http://linkedlifedata.com/resource/pubmed/chemical/Tumor Suppressor Proteins
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0022-2836
pubmed:author
pubmed:issnType
Print
pubmed:day
17
pubmed:volume
349
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
764-73
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:15890360-Amino Acid Sequence, pubmed-meshheading:15890360-CDC2-CDC28 Kinases, pubmed-meshheading:15890360-Cell Cycle Proteins, pubmed-meshheading:15890360-Cell Division, pubmed-meshheading:15890360-Cyclin A, pubmed-meshheading:15890360-Cyclin-Dependent Kinase 2, pubmed-meshheading:15890360-Cyclin-Dependent Kinase 5, pubmed-meshheading:15890360-Cyclin-Dependent Kinase Inhibitor p27, pubmed-meshheading:15890360-Cyclin-Dependent Kinases, pubmed-meshheading:15890360-Humans, pubmed-meshheading:15890360-Kinetics, pubmed-meshheading:15890360-Molecular Sequence Data, pubmed-meshheading:15890360-Nuclear Magnetic Resonance, Biomolecular, pubmed-meshheading:15890360-Peptide Hydrolases, pubmed-meshheading:15890360-Protein Binding, pubmed-meshheading:15890360-Protein Structure, Tertiary, pubmed-meshheading:15890360-Sequence Alignment, pubmed-meshheading:15890360-Spectrometry, Mass, Matrix-Assisted Laser..., pubmed-meshheading:15890360-Structure-Activity Relationship, pubmed-meshheading:15890360-Substrate Specificity, pubmed-meshheading:15890360-Surface Plasmon Resonance, pubmed-meshheading:15890360-Tumor Suppressor Proteins
pubmed:year
2005
pubmed:articleTitle
Molecular basis for the specificity of p27 toward cyclin-dependent kinases that regulate cell division.
pubmed:affiliation
Department of Structural Biology, St Jude Children's Research Hospital, Memphis, TN 38105, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural