St. Jude Children's Research Hospital

About: St. Jude Children's Research Hospital is a healthcare organization based out in Memphis, Tennessee, United States. It is known for research contribution in the topics: Population & Virus. The organization has 9344 authors who have published 19233 publications receiving 1233399 citations. The organization is also known as: St. Jude Children's Hospital & St. Jude Hospital.

p120, a novel substrate of protein tyrosine kinase receptors and of p60v-src, is related to cadherin-binding factors beta-catenin, plakoglobin and armadillo.

Abstract: A novel protein tyrosine kinase (PTK) substrate, p120, has been previously implicated in ligand-induced signaling through the epidermal growth factor, platelet-derived growth factor and colony-stimulating factor 1 receptors, and in cell transformation by p60v-src. We have isolated a near full-length cDNA encoding murine p120. The encoded protein lacks significant homology with any reported protein, but it contains four copies of an imperfect 42 amino acid repeat that occurs 12.5 times in the protein encoded by Drosophila armadillo (arm), and its direct homologs, human plakoglobin (plak) and Xenopus laevis beta-catenin (beta-cat). The presence of this motif implies that p120 may share at least one aspect of its function with the arm protein and its homologs.

p27 binds cyclin-CDK complexes through a sequential mechanism involving binding-induced protein folding.

Abstract: p27 controls cell proliferation by binding and regulating nuclear cyclin-dependent kinases (CDKs). In addition, p27 interacts with other nuclear and cytoplasmic targets and has diverse biological functions. We seek to understand how the structural and dynamic properties of p27 mediate its several functions. We show that, despite showing disorder before binding its targets, p27 has nascent secondary structure that may have a function in molecular recognition. Binding to Cdk2-cyclin A is accompanied by p27 folding, and kinetic data suggest a sequential mechanism that is initiated by binding to cyclin A. p27 regulates CDK-cyclin complexes involved directly in cell cycle control and does not interact with other closely related CDKs. We show that p27-cyclin interactions are an important determinant of this specificity and propose that the homologous cell cycle regulators p21 and p57 function by a similar sequential, folding-on-binding mechanism.