Linked Life Data

9548941

Source:http://linkedlifedata.com/resource/pubmed/id/9548941

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
16
pubmed:dateCreated
1998-5-14
pubmed:abstractText
Proline residues provide a backbone switch in a polypeptide chain, which is controlled by the cis/trans isomerization about the peptidyl-prolyl bond. Phosphorylation of serine- and threonine-proline motifs has been shown to be a critical regulatory event for many proteins. The biological significance of these motifs has been further highlighted by the discovery of a novel and essential peptidyl-prolyl cis/trans isomerase Pin1. Pin1 is required for progression through mitosis via catalyzing the isomerization of phosphorylated Ser/Thr-Pro motifs specifically present in mitosis-specific phosphoproteins. However, little is known whether the phosphorylation regulates the conformational switch of the Ser/Thr-Pro bonds. Here, we report the synthesis and conformational characterization of a series of peptides that contain the phosphorylated or nonphosphorylated Ser/Thr-Pro motifs. Phosphorylation affected the rate of the cis to trans isomerization of the Thr/Ser-Pro bonds. As determined by a protease-coupled assay, the isomerization rate of phosphorylated Thr-Pro bond was found to be 8-fold slower than that of the nonphosphorylated analogue. Furthermore, studies of the pH dependence of the isomerization of the phosphopeptides reveal that both cis content and the rate constant of prolyl cis to trans isomerization are lower for the dianionic state of the phosphothreonine-containing peptides. These effects of phosphorylation are specific for phosphorylated Ser/Thr since neither phosphorylated Tyr nor glutamic acid was able to affect the prolyl isomerization. Finally, our experiments provide evidence that effective catalysis of cis/trans isomerization of phosphorylated Ser/Thr-Pro bonds by Pin1 is specific to the dianionic form of the substrate. Thus, our results demonstrate that protein phosphorylation specifically regulates the backbone dynamics of the Ser/Thr-Pro motifs and that Pin1 specifically isomerizes the certain conformation of the phosphorylated Ser/Thr-Pro motifs.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
21
pubmed:volume
37
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5566-75
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Role of phosphorylation in determining the backbone dynamics of the serine/threonine-proline motif and Pin1 substrate recognition.
pubmed:affiliation
Max-Planck-Research Unit Enzymology of Protein Folding, Halle, Germany.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't