Cell Motility & Cytoskeleton

Cell migration is essential for wound healing, immune and inflammatory responses, and tumour cell metastasis is dependent on cell migration. Our research aims to identify and characterise key signalling molecules involved in the migration of leukocytes, endothelial cells and epithelial cancer cells, which could be targets for therapeutic intervention in human diseases. We are focusing on signal transduction by the Rho family of GTPases, which we have shown play essential roles in cytoskeletal remodelling and changes in cell adhesion during cell migration.

In humans there are 20 Rho GTPases, most of which are regulated by cycling between an active, GTP-bound conformation and an inactive GDP-bound conformation. We are using a combination of RNAi and expression of wildtype and mutant proteins to determine how Rho GTPases, their regulators and downstream target affect cell migration and invasion. Cell migration, invasion, and protein localisation are analysed by confocal and time-lapse microscopy. Biochemical techniques are used to investigate how signalling proteins are regulated and localized within migrating cells, for example by studying changes in protein-protein interactions and protein phosphorylation.

Selected Publications:

1. Riento, K., Totty, N., Garg, R., Villalonga, P., Ridley, A.J. (2005). RhoE function is regulated by ROCK I-mediated phosphorylation. EMBO J 24, 1170-1180.
2. Millan, J., Hewlett, L., Glyn, M., Toomre, D., Clark, P., Ridley, A.J. (2006) Lymphocyte transcellular migration occurs through recruitment of endothelial ICAM-1 to caveola- and F-actin-rich domains. Nature Cell Biol. 8, 113-123.
3. Wheeler, A.P., Wells, C.M., Smith, S.D., Vega, F., Henderson, R.B., Tybulewicz, V.L., Ridley, A.J. (2006) Rac1 and Rac2 regulate macrophage morphology but are not essential for migration. J. Cell Sci.119, 2749-2757.
4. Garg, R., Riento, K., Keep, N.H., Morris, J.D., Ridley AJ. (2008) N-terminus-mediated dimerization of ROCK-I is required for RhoE binding and actin reorganization. Biochem J. 411, 407-414.
5. Smith, S.D., Jaffer, Z.M., Chernoff, J., Ridley, A.J. (2008) PAK1-mediated activation of ERK1/2 regulates lamellipodial dynamics. J. Cell Sci. 121, 3729-3736.
6. Bright, M.D., Ridley, A.J. (2009) PAK1 and PAK2 have different roles in HGF-induced morphological responses. Cellular Signalling 21, 1738-1747.
7. Millán, J., Cain, R.J., Reglero-Real, N., Bigarella, C., Marcos-Ramiro, B., Fernandez-Martin, L., Correas, I., Ridley, A.J. (2010) Adherens junctions connect stress fibers between adjacent endothelial cells. BMC Biol. 8, 11.
8. Cain, R.J., Vanhaesebroeck, B., Ridley, A.J. (2010) The PI3K p110Ą isoform regulates endothelial adherens junctions via Pyk2 and Rac1. J. Cell Biol. 188, 863-876.
9. Takesono, A., Heasman, S.J., Wojciak-Stothard, B., Garg, R., Ridley, A.J. (2010) Microtubules regulate migratory polarity through Rho/ROCK signaling in T cells. PLoS ONE 5, e8774.
10. Heasman, S.J., Carlin, L.M., Ng, T., Ridley, A.J. (2010) Coordinated RhoA signaling at the leading edge and uropod is required for T cell transendothelial migration. J. Cell Biol. 190, 553-563.
11. Vega, F., Fruhwirth, G., Ng, T., Ridley, A.J. (2011) RhoA and RhoC have distinct roles in migration and invasion by acting through different targets. J. Cell Biol. 193, 655-665.

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Our group's focus can loosely be divided into two main interests:

1) Understanding Cell Motility In Vivo
Cell migration is a widely researched and clinically relevant process that, with a greater understanding, may allow us to control a number of pathologies - arguably the most significant being cancer metastasis. However, cell motility has primarily been investigated using cell culture models, which involves watching cells move on artificial 2-dimensional substrates. While these in vitro assays have been useful, there will always be questions surrounding the physiological relevance of studying cell movement ex vivo on tissue culture plastic. Eventually we need to extrapolate our in vitro cell migration knowledge to in vivo physiologically relevant scenarios and our Drosophila macrophage migration model is an excellent place to begin this process. Pertinent to our research interests is that Drosophila macrophage migration is completely amenable to live imaging using standard widefield or confocal microscopy. This in vivo motility system, along with the genetic tractability of flies, creates a powerful model to dissect the genes regulating migration when cells are in their natural environment.

2) The Genetics of a Repair Response
We have recently completed a microarray screen that has allowed us to examine the genes turned on by sterile wounding in Drosophila. This approach has elucidated a number of genes specific to 'wound-activated' macrophages or genes expressed by other tissue types during repair. Aside from an interest in dissecting the function of these novel wound induced genes, we also hope to extrapolate knowledge gained from this genetically tractable system to vertebrate models and ultimately to humans. For instance, we find that GADD45, an epithelial wound gene in the fly, is similarly increased in the skin of mouse wounds highlighting the evolutionary conservation of the genetic program behind wound healing.

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Cell adhesion and migration are critical processes during in normal development and wound healing, but can also contribute to pathological processes such as cancer metastasis. Research in my lab is focused around the study of cell adhesion receptors and how different receptor families control cytoskeleton remodelling and cell migration. We use advanced microscopy approaches coupled with biochemistry and molecular biology to study these events. Understanding the way in which these proteins signal and localise within the cell is key to understanding cell motility in any context.

Selected recent publications:
Morton PE and Parsons M. Dissecting cell adhesion architecture using advanced imaging techniques. Cell Adh Migrn. 2011 In Press.

Morton PE and Parsons M. Measuring FRET using time-resolved FLIM. Methods Mol Biol. 2011. 769:403-413.

Scales TME and Parsons M. Spatial and temporal regulation of integrin signalling during cell migration. Curr Opin Cell Biol. 2011. 20 Jun: e-pub ahead of print.King SJ and Parsons M. Imaging cell within 3D cell-derived matrix. Methods Mol Biol. 2011. 769:53-64.King SJ, Worth DC, Scales TME, Monypenny J, Jones GE and Parsons M. b1 integrins regulate fibroblast chemotaxis through control of N-WASP stability. EMBO J. 2011;30(9):1705-18

Pacary E, Heng J, Azzarelli R, Riou P, Castro D, Lebel-Potter M, Parras C, Bell DM, Ridley AJ, Parsons M, Guillemot F. Proneural transcription factors regulate different steps of cortical neuron migration through Rnd-mediated inhibition of RhoA signalling. Neuron. 2011. 69(6):1069-84

Tavore B, Batista S, Reynolds LE, Jadeja S, Robinson SD, Kostourou V, Hart I, Fruttiger M, Parsons M, Hodivala-Dilke KM. Endothelial Cell FAK is required for tumour angiogenesis. EMBO Mol Med. 2010. Dec;2(12):516-28

Martín-Villar E, Fernández-Muñoz, B, Parsons M, Yurrita MM, Megías M, Pérez-Gómez E, Jones GE and Quintanilla M. Podoplanin associates with CD44 to promote directional cell migration. Mol Biol Cell. 2010; 21(24):4387-9

Worth DC and Parsons M. Advances in imaging cell:matrix adhesions. J Cell Sci. 2010; 123(Pt 21):3629-38..Jayo A and Parsons M. Fascin: a key regulator of cytoskeletal dynamics. Int J Biochem Cell Biol. 2010; Oct;42 (10):1614-1617

Costa P and Parsons M. New insights into the dynamics of cell adhesions. Int Rev Cell Mol Biol. 2010; 283C:57-91.

Theveneau E, Marchant L, Kuriyama S, Gull M, Moepps B, Parsons M, and Mayor R. Collective chemotaxis requires contact dependent cell polarity. Dev Cell 2010; 19 (1), 39-53

Grashoff C, Hoffman BD, Brenner MD, Zhou R, Parsons M, Yang MT, McLean MA, Sligar SG, Chen CS, Ha T, Schwartz MA Measuring mechanical tension across vinculin reveals regulation of focal adhesion dynamics. Nature 2010; 466 (7303): 263-7

Wells CM, Whale AD, Parsons M, Masters JRW, Jones GE. PAK4: a pluripotent kinase that regulates prostate cancer cell adhesion. J Cell Sci. 2010. Apr; 123:1663-1673

Worth DC, Hodivala-Dilke K, Robinson SD, King SJ, Morton PE, Gertler FB, Humphries MJ, Parsons M. avb3 integrin spatially regulates VASP and RIAM to control adhesion dynamics and migration. J Cell Biol. 2010. Apr 19; 189(2):369-83

Conklin MW, Ada-Nguema A, Parsons M, Riching KM, Keely PJ. R-Ras regulates β1-integrin trafficking via effects on membrane ruffling and endocytosis. BMC Cell Biol. 2010. Feb; 11(1): 14

Zhang W, Parsons M, McConnell G. Flexible and stable optical parametric oscillator based laser system for coherent anti-Stokes Raman scattering microscopy. Micros Res Tech. Nov 2009 epub. doi: 10.1002/jemt.20806

Lai-Cheong JE, Parsons M, McGrath JE. The cellular roles of fermitin family homolog proteins. Int J Biochem Cell Biol. 2010; 42: 595-603

Worth DC and Parsons M. Live cell imaging analysis of receptor function. Methods Mol Biol. 2010; 591:311-23

van Diepen M, Parsons M, Downes PC, Leslie NR, Hindges R, Eickholt BJ. Myosin V controls PTEN function and neuronal cell size. Nat Cell Biol. 2009. Oct; 11(10):1191-

Lai-Cheong JE, Parsons M, Tanaka A, Ussar S, South AP, Gomathy S, Mee JB, Barbaroux JB, Techanukul T, Almaani N, Clements S, Hart I, McGrath JA. Loss-of-function FERMT1 mutations in Kindler syndrome implicate a role of fermitin family homolog-1 in integrin activation. Am J Path. 2009. Oct; 175(4):1431-4

Emerson LJ, Holt MR, Wheeler MA, Wehnert M, Parsons M, Ellis JE. Defects in cell spreading and ERK1/2 activation in fibroblasts with lamin A/C mutations. Biochem Biophys Acta. 2009. 1792; 810-821

Farmer C, Morton PE, Snippe M, Santis G, Parsons M. Coxsackie adenovirus receptor (CAR) regulates integrin function through activation of p44/42 MAPK. Exp Cell Res. 2009. July; 315, 2637-47.

Killock D*, Parsons M*, Zarrouk M, Ameer-Beg SM, Ridley AJ, Haskard DO, Zvelibil M, Ivetic A. In vitro and in vivo characterization of molecular interactions between calmodulin, ezrin/radixin/moesin (ERM) and L-selectin. J Biol Chem. 2009 Mar; 284(13):8833-45

Carmona-Fontaine C, Matthews HK, Kuriyama S, Moreno M, Dunn G, Parsons M, Stern CD, Mayor R. Contact Inhibition of Locomotion in vivo controls neural crest directional migration via the non-canonical Wnt signalling. Nature. 2008 Dec; 456(7224); 957-61

Geraldo S, Khanzada UK, Parsons M, Chilton JK, Gordon-Weeks PR. Targeting of the F-actin-binding protein drebrin by the microtubule +TIP protein EB3 is required for neuritogenesis. Nat Cell Biol. 2008 Oct; 10(10); 1181-9.

Worth D and Parsons M. Adhesion dynamics: mechanisms and measurements. Int J Biochem Cell Biol. 2008 Aug; 40(11), 2397-2409.Parsons M and Adams JC. Rac regulates the interaction of fascin with protein kinase C in cell migration. J Cell Sci. 2008 Aug; 121; 2805-13

Matthews HK, Marchant L, Carmona-Fontaine1 C, Kuriyama S, Larraín J, Holt MR, Parsons M, Mayor R. Directional migration of Neural Crest cells in vivo is regulated by Syndecan-4/Rac1 and non-canonical Wnt signalling/RhoA. Development 2008 May; 135(10); 1771-80

Parsons M, Messent AJ, Humphries JD, Deakin NO, Humphries MJ. Quantitation of integrin receptor agonism by fluorescence lifetime imaging. J Cell Sci. 2008. Jan; 121(3): 265-27

Caswell PT, Spence HJ, Parsons M, White DP, Clark K, Cheng KW, Mills GB, Humphries MJ, Messent AJ, Anderson KI, McCaffrey MW, Ozanne BW, Norman JC. Rab25 Associates with alpha5beta1 Integrin to Promote Invasive Migration in 3D Microenvironments. Dev Cell. 2007 Oct;13(4); 496-51

Hashimoto Y, Parsons M*, Adams JC*. Dual actin-bundling and protein kinase C-binding activities of fascin regulate carcinoma cell migration downstream of Rac, and contribute to metastasis. Mol Biol Cell. 2007. Nov;18(11):4591-602

Prag S*, Parsons M*, Keppler MD, Ameer-Beg SM, Barber P, Hunt J, Beavil AJ, Calvert R, Arpin M, Vojnovic B, Ng T. Activated ezrin promotes cell migration through recruitment of the GEF Dbl to lipid rafts and preferential downstream activation of Cdc42. Mol Biol Cell. 2007 Aug;18(8):2935-48.

Ramsay AG, Keppler MD, Jazayeri M, Thomas GJ, Parsons M, Violette S, Weinreb P, Hart IR, Marshall JF. HAX-1 regulates carcinoma cell migration and invasion via clathrin-mediated endocytosis of integrin avb6. Cancer Res 2007 Jun 67(1); 5275-84

Byrne RD, Rosivatz E, Parsons M, Larijani B, Parker PJ, Ng T and Woscholski R. Differential activation of the PI 3-kinase effectors AKT/PKB and p70 S6 kinase by compound 48/80 is mediated by PKCa. Cell Sig 2007 Feb;19(2):321-

Lord R, Parsons M, Kirby I, Beavil A, Hunt J, Sutton B, Santis G. Analysis of the interaction between RGD-expressing adenovirus type 5 fiber knob domains and avb3 integrin reveals distinct binding profiles and intracellular trafficking. J Gen Virol. 2006 87(Pt 9):2497-50

Parsons M, Monypenny J, Ameer-Beg SM, Millard TM, Machesky LM, Peter M, Chernoff J, Zicha D, Vojnovic B and Ng T. Spatially distinct binding of Cdc42 to PAK1 and N-WASP in breast carcinoma cells. Mol Cell Biol. 2005 ;25(5):1680-95

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The goal of our research is to elucidate mechanisms that regulate cytoskeletal remodelling during cell migration and axon guidance.

Directed cell motility is essential for multicellular animal development, lymphocyte chemotaxis, and navigation of growing axons in the developing nervous system. Protrusion of a cell or growth cone toward attractive cues depends on activation of receptors that lead to an activation of Rho GTPases and in the case of chemotactic cells to an asymmetric distribution of specific phospholipids. Finally, the polymerization of actin filaments, a process regulated by several proteins including the MRL protein family (MIG-10, RIAM, Lamellipodin (Lpd), and Pico), the Ena/VASP family (Mena, VASP, EVL), N-WASP and the Arp2/3 complex, provides the force for plasma membrane protrusion.

The work in our group focuses on signalling mechanisms that regulate the actin cytoskeleton downstream of growth factor and axon guidance receptors. We are utilizing live cell microscopy to analyze quantitatively the effects of genetically altered levels of signalling molecules on cytoskeletal dynamics, growth cone behaviour, cell polarity, and cell migration. Biochemical analysis of signalling complexes complements this analysis.

In the quest for molecules that link cell surface receptors to effectors of the actin cytoskeleton we have identified Lamellipodin (Lpd) as a novel Ena/VASP binding protein. Both proteins co-localize at the tips of lamellipodia and filopodia. Lpd contains a Ras association domain and a PH domain that binds specifically to PI(3,4)P2, an asymmetrically localized signal in chemotactic cells.

Overexpression of Lpd increases speed and reduces persistence of lamellipodial protrusion, in an Ena/VASP dependent fashion. Conversely, knockdown of Lpd expression leads to impairment in lamellipodia formation, reduction in velocity of residual lamellipodial protrusion and decrease in F-actin content. Furthermore Lpd and its fly ortholog Pico are required for EGF induced proliferation and this is mediated through the SRF transcription factor. Thus, Lpd may act as a key convergence point linking polarized phospholipid signals and small Ras GTPases with Ena/VASP proteins to regulate the actin cytoskeleton and cell proliferation.

How cells regulate and execute cytokinesis, the final step of cell division, remain major unsolved questions in basic biology. Cytokinesis requires the coordinated action of the cytoskeleton, the cell cycle, and membrane machineries. We use chemical biology approaches to study cytokinesis at the process, pathway and protein levels, in three interconnected programmes:

1) Small molecules and cytokinesis: Cytokinesis has been difficult to study because it is a complex, rapid and dynamic process and many key proteins also perform important functions earlier in the cell cycle. Small molecules that act rapidly and can be added at specific time points for live imaging are ideal tools to dissect cytokinesis. We are in the process of creating a toolbox of small molecules that inhibit different proteins and pathways in cytokinesis, using technologies we developed that integrate chemical and genomic methods to target specific signalling pathways, with an emphasis on the pathway centred on Rho GTPase.

2) Cytokinesis and endocytosis: Although we know that endocytosis is essential for cytokinesis, there are many outstanding questions about how these two processes interface. We discovered a small molecule, XZ-1, that is both a potent inhibitor of cytokinesis and an inducer of endocytic tubulation. XZ-1 is thus an ideal tool to study how cytokinesis and endocytosis are connected. We are using a combination of genome-wide RNAi and imaging approaches to investigate how XZ-1 exerts its effects.

3) Cytokinesis and lipids: While it is known that cell membranes undergo dramatic structural rearrangements during cytokinesis, and it is obvious that membrane rearrangements are needed to seal daughter cells after severing, very little is known about whether (and how) specific lipids are involved in cytokinesis. We are well on our way to answering these questions, using mass spectrometry, imaging and small molecule perturbations.

020 7848 8463

Individual tumour cells have 2 modes of movement: an elongated mode requiring extracellular proteolysis at cellular protrusions and a rounded mode where cell movement is driven by high contractile forces. Tumour cells can switch between those two different modes of movement. We carry out research that is directed to study how Rho GTPases control gene expression patterns that determine the different types of movement and relate these genes to tumour spread in patients. The ultimate goals will be to find genes with potential prognostic value and validate some of these genes as good therapeutic targets.

Our lab uses a wide array of techniques such as Microarray analysis, RNAi, over-expression approaches, 3D invasion/imaging techniques and in vivo metastasis assays to understand the roles of these genes in determining modes of movement. The tumour microenvironment is a major focus of our research as it could potentially regulate these two migratory modes. Our group is funded by Cancer Research UK :

http://science.cancerresearchuk.org/funding/find-grant/all-funding-schemes/career-development-fellowship/