SH2/SH3 adaptors of the Crk and Nck families transduce signals by bringing together tyrosine-phosphorylated proteins that bind their SH2 domains with downstream effectors that bind their SH3 domains. These adaptors play a critical role in regulating a variety of normal cell behaviors such as adhesion and motility, while abnormal signaling by Crk can induce oncogenic transformation and may play a role in human cancer. Despite their central role in signaling, understanding their mechanism of action is challenging because they bind to many proteins in the cell with similar affinity, and their activities are highly dependent on their subcellular localization and the local concentration of potential binding partners. We propose an interdisciplinary research plan, using approaches ranging from quantitative computational modeling, phosphoproteomics, live-cell imaging, and in vivo tumorigenicity assays, to reveal in molecular detail the mechanism of action of Crk and Nck adaptors in important biological activities. Specifically, the experiments proposed here will 1.) elucidate the molecular basis for the positive role for the Sos1 guanine nucleotide exchange factor (GEF) and the negative role for Abl tyrosine kinases in transformation by Crk;2.) elucidate the mechanisms whereby Abl-Crk and Abl-Nck complexes regulate local actin cytoskeletal organization, such as the balance between filopodia and lamellipodia in spreading cells;and 3.) use a spatial computational model of actin dynamics, together with experimental methods to manipulate local concentrations of Nck and other signaling proteins in living cells, to obtain a quantitative understanding o how Nck controls the local state of actin polymerization in the cell.
Signals mediated by tyrosine phosphorylation control a host of important biological activities, and when dysregulated can cause human diseases such as cancer and immune disorders. SH2/SH3 adaptors play a central role in tyrosine kinase signaling, but their specific mechanism of action is poorly understood. The proposed studies will provide specific, mechanistic details about adaptor function that will provide insight into basic biological processes as well as how these processes can be subverted in disease.
|Borinskaya, Sofya; Velle, Katrina B; Campellone, Kenneth G et al. (2016) Integration of linear and dendritic actin nucleation in Nck-induced actin comets. Mol Biol Cell 27:247-59|
|Ng, K Y; Yin, T; Machida, K et al. (2015) Phosphorylation of Dok1 by Abl family kinases inhibits CrkI transforming activity. Oncogene 34:2650-9|
|Gifford, Stacey M; Liu, Weizhi; Mader, Christopher C et al. (2014) Two amino acid residues confer different binding affinities of Abelson family kinase SRC homology 2 domains for phosphorylated cortactin. J Biol Chem 289:19704-13|
|Taslimi, Amir; Vrana, Justin D; Chen, Daniel et al. (2014) An optimized optogenetic clustering tool for probing protein interaction and function. Nat Commun 5:4925|
|Jones, Matthew C; Machida, Kazuya; Mayer, Bruce J et al. (2013) Paxillin kinase linker (PKL) regulates Vav2 signaling during cell spreading and migration. Mol Biol Cell 24:1882-94|
|Ditlev, Jonathon A; Mayer, Bruce J; Loew, Leslie M (2013) There is more than one way to model an elephant. Experiment-driven modeling of the actin cytoskeleton. Biophys J 104:520-32|
|Gutierrez-Uzquiza, Alvaro; Colon-Gonzalez, Francheska; Leonard, Thomas A et al. (2013) Coordinated activation of the Rac-GAP ?2-chimaerin by an atypical proline-rich domain and diacylglycerol. Nat Commun 4:1849|
|Oh, Dongmyung; Ogiue-Ikeda, Mari; Jadwin, Joshua A et al. (2012) Fast rebinding increases dwell time of Src homology 2 (SH2)-containing proteins near the plasma membrane. Proc Natl Acad Sci U S A 109:14024-9|
|Ditlev, Jonathon A; Michalski, Paul J; Huber, Greg et al. (2012) Stoichiometry of Nck-dependent actin polymerization in living cells. J Cell Biol 197:643-58|
|Sriram, G; Reichman, C; Tunceroglu, A et al. (2011) Phosphorylation of Crk on tyrosine 251 in the RT loop of the SH3C domain promotes Abl kinase transactivation. Oncogene 30:4645-55|
Showing the most recent 10 out of 33 publications