Spatiotemporal Dynamics of Rho-family GTPases in living cells, visualized by fluorescent biosensors.

P21 Rho family small GTPases are critically important in many disease processes including malignant cancers, developmental defects, arthrosclerosis and autoimmune dysfunction. This class of signaling molecules is critical in these diseases by impacting directly: cell polarity, motility and migration through their actions on downstream cytoskeleton/adhesion dynamics; and proliferation by intersecting mitogenic and apoptotic signaling pathways. Rho family GTPases regulate these processes by tightly coordinating their activities in response to various environmental cues. Only a very small fraction of GTPases turn on or off at different locations at different times to produce specific effects. Furthermore, most Rho GTPases exist in an interdependent cascade of activation/inhibition pathways resulting in a tight coordination of activation dynamics between each other. It is this coordination of multiple GTPases that is thought to regulate a variety of cellular signaling outcomes. However it has been difficult if not impossible to dissect the spatiotemporal dynamics of signal regulation by conventional imaging or biochemical techniques.

My primary research interest is the development of fluorescent biosensors to visualize and decipher these complex spatiotemporal dynamics of protein activations in living cells in real time. These biosensors enable direct visualization of the spatiotemporal dynamics of protein signaling pathways at high resolution, previously inaccessible by traditional biochemical methods. Knowledge gained from these studies will open a new window into previously unseen, coordinated mechanisms of GTPase signal regulation.

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Pertz, O., Hodgson, L., Klemke, R. L., and Hahn, K. M. (2006) “Spatio-temporal Analysis of RhoA Activity in Cell Migration”. Nature: Vol. 440; 1069-72.

Hodgson, L., Chan, E., Hahn, K., and Yousaf, M. (2007) “Combining Surface Chemistry with a FRET-based Biosensor to Study the Dynamics of RhoA GTPase Activations in Cells on Patterned Substrates”. Journal of American Chemical Society: Vol. 129(30), 9264 -9265.

Garrett, S., Hodgson, L., Rybin, A., Toutchkine, A., Hahn, K., Lawrence, D., and Bresnick, A. (2008) “A Biosensor of S100A4 Metastasis Factor Activation ­ Inhibitor Screening and Cellular Activation Dynamics”: Biochemistry: Vol. 47(3), 986-96

Machacek, M.*, Hodgson, L.*, Welch, C.*, Elliott, H., Nalbant, P., Pertz, O., Abell, A., Johnson, G., Hahn, K., and Danuser, G. (2009) “Coordination of Rho GTPase activation during protrusion”. Nature: Vol. 461, 99-103. * authors contributed equally.

Bravo-Cordero, J. J., Oser, M., Chen, X., Eddy, R., Hodgson, L. and Condeelis, J. (2011) “A novel spatiotemporal RhoC activation pathway locally regulates cofilin activity at invadopodia”. Current Biology: Vol. 21(8), 635-44.

Bravo-Cordero, J. J., Sharma, V. P., Roh-Johnson, M., Chen, X., Eddy, R., Condeelis, J., and Hodgson, L. (2013) “Spatial regulation of RhoC activity defines protrusion formation in migrating cells”. J. Cell Science: Aug 1;126(Pt 15):3356-69. 

Zawistowski, J., Sabouri, M., Danuser, G., Hahn, K., and Hodgson, L. (2013) “Differential activation of RhoA and RhoC in migrating cells”. Plos One 2013 Nov 5;8(11):e79877.

Minna Roh-Johnson, J. Javier Bravo-Cordero, Antonia Patsialou, Ved P. Sharma, Huiping Liu, Louis Hodgson and John Condeelis (2013) “Macrophage contact induces RhoA GTPase signaling to trigger tumor cell intravasation”. Oncogene Sep 23 [Epub ahead of print]

Lázaro-Diéguez, F., Cohen, D., Fernandez, D, Hodgson, L., van IJzendoorn, S. C. D., and  Müsch, A. (2013) “Par1b coordinates lumen polarity with mitotic spindle orientation in kidney- and hepatocyte- derived epithelial cells”. J. Cell Biology: 2013 Oct 28;203(2):251-64.

Moshfegh Y*, Bravo-Cordero JJ*, Miskolci V, Condeelis J and Hodgson L. “A Trio-Rac1-PAK1 signaling axis drives invadopodia disassembly”. (2014) Nat Cell Biol, Vol.16, No6. 574-86. *authors contributed equally. Article recommended by Faculty of 1000. Science Signaling Editor’s Choice June 2014.

Hanna S*, Miskolci V*, Cox D^% and Hodgson L.^% “A new genetically encoded single-chain biosensor for Cdc42 based on FRET, useful for live-cell imaging.” (2014) PLOS ONE May 5;9(5):e96469. doi: 10.1371/journal.pone.0096469.  ^%co-corresponding authors.

Beaty BT, Wang Y, Bravo-Cordero JJ, Sharma VP, Miskolci V, Hodgson L and Condeelis J. “Talin regulates the sodium/hydrogen exchanger-1 (NHE-1) and promotes mammary tumorigenesis.” (2014) J Cell Biol, Jun 2. pii: jcb.201312046. [Epub ahead of print]

Sun, Q., Luo, T., Shirasawa, S., Sasazuki, T., Cibas, E. S., Hodgson, L., Robinson, D. N., and Overholtzer, M. (2014) “Induction of entosis by epithelial cadherin expression”. Cell Res.: Vol. 24(11):1288-98

Ioannou, MS, Bell, ES, Girard, M, Chaineau, M, Hamlin, JN, Daubaras, M, Monast, A, Park, M, Hodgson, L, and McPherson, PS. (2015) “Localized activation of Rab13 at cortical actin drives membrane protrusions and invasive cell behaviour required for cancer progression”. J. Cell Biology: Mar 2;208(5):629-48.

Wu, B, Miskolci, V, Donnelly, SK, Cox, D, Singer, RH^% and Hodgson, L.^% (2015) “Synonymous modification of repeated sequences in retroviral reporters.”  ^%co-corresponding authors.  Genes & Development: Apr 15;29(8):876-86. doi: 10.1101/gad.259358.115. Epub 2015 Apr 15.

Miskolci, V., Wu, B., Moshfegh, Y., Cox, D.^% and Hodgson, L. ^% (2016) “Optical tools to study the isoform-specific roles of small GTPases in immune cells”. Journal of Immunology: Apr 15:196(8). ^%co-corresponding authors.

Hodgson, L.*^%, Spiering, D.*, Sabouri, M., DerMadirossian, C., Danuser, G.^%, and Hahn, K.^% (2016) “FRET binding antenna reports spatiotemporal dynamics of GDI–Cdc42 GTPase interactions”. Nature Chemical Biology: Aug 8: 12(10). *authors contributed equally, ^%co-corresponding authors.

Bouchet, B.P., Noordstra, I., Hodgson, L., Dogterom, M. and Akhmanova, A. (2016). “Mesenchymal cell invasion requires cooperative regulation of persistent microtubule growth by SLAIN2 and CLASP1.” Developmental Cell: Dec 19;39(6):708-723.

Pignatelli, J.*, Bravo-Cordero, J.J.*, Roh-Johnson, M., Gandhi, S.J., Wang, Y., Chen, X., Eddy, R.J., Xue, A., Singer, R.H., Hodgson, L., Oktay, M. and Condeelis, J. (2016) “Macrophage-dependent tumor cell transendothelial migration is mediated by Notch1/Mena^INV-initiated invadopodium formation.”  Scientific Reports: Nov 30;6:37874.

Cao L, Riascos-Bernal D, Chinnasamy P, Dunaway C, Hou R, Pujato M, O'Rourke B, Miskolci V, Guo L, Hodgson L, Fiser A, and Sibinga N. (2016) “Control of mitochondrial function and cell growth by the atypical cadherin Fat1.” Nature:  Nov 24;539(7630):575-578. 

Franco, A., Kitsis, R.N., Fleischer, J.A., Gavathiotis, E., Kornfeld, O.S., Gong, G., Biris, N., Benz, A., Qvit, N., Donnelly, S.K., Chen, Y., Mennerick, S., Hodgson, L., Mochly-Rosen, D., and Dorn II, G.W. (2016) “Correcting mitochondrial fusion defects by manipulating mitofusin conformation.” Nature: Dec 1;540(7631):74-79.

Hanna, S.J., McCoy-Simandle, K., Miskolci, V., Guo, P., Cammer, M., Hodgson, L., and  Cox, D. (2017) “The Role of Rho-GTPases and actin polymerization during Macrophage Tunneling Nanotube Biogenesis.”  Scientific Reports: Aug 17; 7(1): 8547. 

Donnelly, S.K., Cabrera, R., Chiang, S., Christin, J.R., Wu, B., Guo, W., Bravo-Cordero, J.J., Condeelis, J.S., Segall, J.E., and Hodgson, L. (2017) “Rac3 regulates breast cancer invasion and metastasis by controlling adhesion and matrix degradation.” J. Cell Biology: Dec 4;216(12):4331-4349. 

Liu, J.A., Rao, Y., Cheung, M.P.L., Hui, M.N., Wu, M.H., Niu, B., Chan, L.K., Ng, I.O.L., Cheah, K.S.E., Hodgson, L., and Cheung, M. (2017) “Asymmetric localization of Dlc1 defines neural crest polarity for directional migration.” Nature Communications: Oct 30;8(1):1185.

Shcherbakova, D.M., Cox Cammer, N., Huisman, T.M., Verkhusha, V.V.^% and Hodgson, L.^% (2018) “Direct multiplex imaging and optogenetics of RhoGTPases enabled by near-infrared FRET.” Nature Chemical Biology: in Press  ^%co-corresponding authors