Rho family GTPases is ubiquitous molecular switches that control extraordinarily diverse cellular processes. They are activated by guanine nucleotide exchange factors (GEFs) that are roughly 5-fold more numerous than the GTPases themselves and integrate the many cellular inputs controlling GTPase function. GEFs and GTPases form complex networks that are constituted transiently and locally for specific purposes. Biochemical, genetic, molecular, and structural analyses have unraveled a great deal about these critically important pathways, but the most important functional property, their spatio-temporal regulation, can only be fully understood in the context of intact cells. This PPG brings together team members with diverse expertise to develop innovative technologies enabling the study of GEF/GTPase networks in vivo, computational tools to extract network architecture and signaling kinetics from imaging data, and in-depth knowledge of cell behaviors critically dependent on GEF/GTPase dynamics: (Project 1- Hahn) will deliver GEF biosensors based on designs addressing different GEF structural classes. In a collaborative effort with Sondek, expert in GEF structure, different biosensor designs will report GEF activation by specific upstream inputs, and activation of endogenous GEFs. (Project 2- Danuser) will develop the ability to simultaneously image and/or photomanipulate the activity of any pair of GEFs and GTPases, for high resolution studies of GEF/GTPase spatio-temporal coordination. New computational tools will combine data from different experiments to model large networks, and to extract network architecture and signaling kinetics from imaging data. These methods will be tested in studies of complex GEF-GTPase feedback interactions. (Project 3- Hall): This biologically focused project will extend our work to multicellular systems. We will focus on GEF activation in cell-cell junctions and cryptic lamellipodia, and identify GEFs regulating collective migration. (Project 4- Burridge) will address the role of GEF/GTPase netvvorks in mechanotransduction, exploring novel findings regarding the mechanical regulation of RhoA signaling at cell-matrix and cell-cell adhesions during initiation of protrusions, and in the nucleus.
Little is known about how the cell uses networks of 'signaling proteins'for many purposes by controlling when and where they assemble. We will generate tools to address the dynamics of such networks in space and time within living cells, and study specific networks composed of GEFs and GTPases, ubiquitous proteins involved in many basic cell behaviors and diseases.
|Woodham, Emma F; Paul, Nikki R; Tyrrell, Benjamin et al. (2017) Coordination by Cdc42 of Actin, Contractility, and Adhesion for Melanoblast Movement in Mouse Skin. Curr Biol 27:624-637|
|Takano, Tetsuya; Wu, Mengya; Nakamuta, Shinichi et al. (2017) Discovery of long-range inhibitory signaling to ensure single axon formation. Nat Commun 8:33|
|Zaritsky, Assaf; Obolski, Uri; Gan, Zhuo et al. (2017) Decoupling global biases and local interactions between cell biological variables. Elife 6:|
|Zaritsky, Assaf; Tseng, Yun-Yu; Rabadán, M Angeles et al. (2017) Diverse roles of guanine nucleotide exchange factors in regulating collective cell migration. J Cell Biol 216:1543-1556|
|Taylor, A B; Ioannou, M S; Watanabe, T et al. (2017) Perceptually accurate display of two greyscale images as a single colour image. J Microsc 268:73-83|
|Herrington, Kari A; Trinh, Andrew L; Dang, Carolyn et al. (2017) Spatial analysis of Cdc42 activity reveals a role for plasma membrane-associated Cdc42 in centrosome regulation. Mol Biol Cell 28:2135-2145|
|Lawson, Campbell D; Fan, Cheng; Mitin, Natalia et al. (2016) Rho GTPase Transcriptome Analysis Reveals Oncogenic Roles for Rho GTPase-Activating Proteins in Basal-like Breast Cancers. Cancer Res 76:3826-37|
|Wang, Hui; Vilela, Marco; Winkler, Andreas et al. (2016) LOVTRAP: an optogenetic system for photoinduced protein dissociation. Nat Methods 13:755-8|
|Hodgson, Louis; Spiering, Désirée; Sabouri-Ghomi, Mohsen et al. (2016) FRET binding antenna reports spatiotemporal dynamics of GDI-Cdc42 GTPase interactions. Nat Chem Biol 12:802-809|
|MacNevin, Christopher J; Toutchkine, Alexei; Marston, Daniel J et al. (2016) Ratiometric Imaging Using a Single Dye Enables Simultaneous Visualization of Rac1 and Cdc42 Activation. J Am Chem Soc 138:2571-5|
Showing the most recent 10 out of 24 publications