Louise Cramer Research Group

1987 BSc Imperial College London
1991 PhD Imperial College London
Louise Cramer
Tel: 020 7679 7260 (office)
Tel: 020 7679 7264 (lab)
Fax: 020 7679 7805
Awards: 
1987 Biochemistry Excellence Prize (Imperial College London)
1987 Medical Research Council pre-doctoral fellowship
1990 Young Cell Biologist of the Year (British Society for Cell Biology)
1991 Human Frontiers post-doctoral fellowship
1994 American Cancer Society senior postdoctoral fellowship
1997 Wellcome Trust Career Development Award
1998-2008 Royal Society University Research Fellowship
2001 Renewal of Royal Society University Research Fellowship
2002 Royal Society Merit Award for research excellence
2004 Renewal of Royal Society University Research Fellowship
Previous Posts: 
1991-1997 Postdoctoral Fellow University of California San Francisco, San Francisco USA
1997-1998 Scientist, Kings College London
Cramerfig1.jpg

actin filament organization in a migrating fibroblast

The Cramer laboratory studies cytoskeleton mechanisms in cell polarity and cell migration. Cell migration is essential for life; required throughout embryo development, and for tissue repair and immunity in both the embryo and the adult. It also contributes to several important diseases, including inflammatory diseases, mental retardation and the spread of cancer. Determining molecular mechanisms controlling cell migration thus promises to provide effective therapeutic strategies for treating disease. We are interested in how migrating cells reach new territory and how they polarize to activate motility. We focus on determining actin cytoskeleton-based mechanical forces that drive these processes analysed at high spatiotemporal resolution, mainly using primary fibroblasts as model systems.

 

Projects

Establishment of Cell Polarity

Cramerfig2.jpg

Model for how cells initiate cell polarization from the cell front and cell rear.

To initiate directed migration a cell must break cell symmetry and form a
cell front and cell back, at opposing ends of the cell along an axis
approximately aligned with the direction of locomotion. In the main,
actin-based mechanical forces first shape - and then propel - the cell
front and cell rear forwards in the direction of migration. We recently
discovered that constitutive cell migration is initiated from the cell
rear, not the cell front, the common view. Our findings provide a new
perspective on how cells polarize. To determine precise mechanism, we
are currently investigating the precise temporal order and spatial
organization of actin-based mechanical forces likely to be important for
triggering initial breaking of cell symmetry from the cell rear.

ADF/cofilin

Cramerfig3small_0.jpg

Ratio of actin monomer and actin filaments in a migrating fibroblast.

In
collaboration with Prof. Jim Bamburg’s lab at Colorado State University
we were the first to identify that actin depolymerization and the
ADF/cofilin family of proteins that regulate actin depolymerization are
necessary for cell polarization in migrating cells. This was
subsequently also discovered for several other migrating cell types by
other labs, thus increasingly revealing the importance of these proteins
for triggering migration. Our current endeavours focus on our finding
that ADF/cofilin controls the formation of oriented actomyosin II
bundles in the cell body that in turn specifies the formation of the
front and back of the cell around the ends of the bundles during cell
polarization. We are investigating the mechanism of formation of
oriented actin bundles and the spatiotemporal regulation of ADF/cofilin
in triggering polarization and maintaining migration.

We found that the ratio of monomer:polymer is low (blue) within the
cell front. Consistent with this, we also discovered that actin
filaments are immediately recycled (depolymerised) to provide monomer
fuel to sustain actin polymerization-driven cell protrusion in migrating
cells.

Publications
Jump to: 2013 | 2012 | 2011 | 2010 | 2009 | 2008 | 2007 | 2005 | 2004 | 2003 | 2002 | 2001 | 2000 | 1999 | 1997 | 1996 | 1995 | 1994 | 1993 | 1992 | 1990
Number of items: 45.

2013

Cramer, LP; (2013) Mechanism of cell rear retraction in migrating cells. CURRENT OPINION IN CELL BIOLOGY , 25 (5) 591 - 599. 10.1016/j.ceb.2013.05.001.

2012

Kalaji, R; Wheeler, AP; Erasmus, JC; Lee, SY; Endres, RG; Cramer, LP; Braga, VM; (2012) ROCK1 and ROCK2 regulate epithelial polarisation and geometric cell shape. Biol Cell , 104 (8) 435 - 451. 10.1111/boc.201100093.

Nightingale, TD; Cutler, DF; Cramer, LP; (2012) Actin coats and rings promote regulated exocytosis. Trends Cell Biol , 22 (6) 329 - 337. 10.1016/j.tcb.2012.03.003.

2011

Mseka, T; Cramer, LP; (2011) Actin depolymerization-based force retracts the cell rear in polarizing and migrating cells. Curr Biol , 21 (24) 2085 - 2091. 10.1016/j.cub.2011.11.006.

Nightingale, TD; White, IJ; Doyle, EL; Turmaine, M; Harrison-Lavoie, KJ; Webb, KF; ... Cutler, DF; + view all (2011) Actomyosin II contractility expels von Willebrand factor from Weibel-Palade bodies during exocytosis. J CELL BIOL , 194 (4) 613 - 629. 10.1083/jcb.201011119.

2010

Cramer, LP; (2010) Forming the cell rear first: breaking cell symmetry to trigger directed cell migration. NAT CELL BIOL , 12 (7) 628 - 632.

2009

Mseka, T; Coughlin, M; Cramer, LR; (2009) Graded Actin Filament Polarity is the Organization of Oriented Actomyosin II Filament Bundles Required for Fibroblast Polarization. CELL MOTIL CYTOSKEL , 66 (9) 743 - 753. 10.1002/cm.20403.

2008

Anderson, TW; Vaughan, AN; Cramer, LP; (2008) Retrograde Flow and Myosin II Activity within the Leading Cell Edge Deliver F-Actin to the Lamella to Seed the Formation of Graded Polarity Actomyosin II Filament Bundles in Migrating Fibroblasts. MOL BIOL CELL , 19 (11) 5006 - 5018. 10.1091/mbc.E08-01-0034.

Cramer, L; (2008) Organelle Transport: Dynamic Actin Tracks for Myosin Motors. CURR BIOL , 18 (22) R1066 - R1068. 10.1016/j.cub.2008.09.048.

2007

Mseka, T; Bamburg, JR; Cramer, LP; (2007) ADF/cofilin family proteins control formation of oriented actin-filament bundles in the cell body to trigger fibroblast polarization. J CELL SCI , 120 (24) 4332 - 4344. 10.1242/jcs.017640.

Rampaul, A; Parkin, IP; Cramer, LP; (2007) Damaging and protective properties of inorganic components of sunscreens applied to cultured human skin cells. J PHOTOCH PHOTOBIO A , 191 (2-3) 138 - 148. 10.1016/j.jphotochem.2007.04.014.

2005

Zhang, J.; Betson, M.; Erasmus, J.; Zeikos, K.; Bailly, M.; Cramer, L.P.; Braga, V.M.M.; (2005) Actin at cell-cell junctions is composed of two dynamic and functional populations. Journal of Cell Science , 118 (23) pp. 5549-5562. 10.1242/jcs.02639. Green open access
file

Zhang, JK; Betson, M; Erasmus, J; Zeikos, K; Bailly, M; Cramer, LP; Braga, VMM; (2005) Actin at cell-cell junctions is composed of two dynamic and functional populations. J CELL SCI , 118 (23) 5549 - 5562. 10.1242/jcs.02639.

2004

Cramer, LP; Bamburg, JR; Mseka, T; (2004) Microtubules spatially regulate ADF/cofilin to control cell polarity during migration. In: MOLECULAR BIOLOGY OF THE CELL. (pp. 384A - 384A). AMER SOC CELL BIOLOGY

Mseka, T; Dawe, HR; Bamburg, JR; Cramer, LP; (2004) Actin filament depolymerization and microtubules control sequential actin dynamic steps to initiate cell polarity. In: MOLECULAR BIOLOGY OF THE CELL. (pp. 385A - 385A). AMER SOC CELL BIOLOGY

Rosenblatt, J; Cramer, LP; Baum, B; McGee, KM; (2004) Myosin II-dependent cortical movement is required for centrosome separation and positioning during mitotic spindle assembly. In: MOLECULAR BIOLOGY OF THE CELL. (pp. 378A - 378A). AMER SOC CELL BIOLOGY

Rosenblatt, J; Cramer, LP; Baum, B; McGee, KM; (2004) Myosin II-dependent cortical movement is required for centrosome separation and positioning during mitotic spindle assembly. CELL , 117 (3) 361 - 372.

Tahtamouni, LH; Cramer, LP; Bamburg, JR; (2004) Role of mDia1 in directional migration and polarization of chick fibroblasts. In: MOLECULAR BIOLOGY OF THE CELL. (pp. 41A - 42A). AMER SOC CELL BIOLOGY

2003

Dawe, HR; Minamide, LS; Bamburg, JR; Cramer, LP; (2003) ADF/Cofilin controls cell polarity during fibroblast migration. CURR BIOL , 13 (3) 252 - 257.

2002

Cramer, LP; (2002) Ena/Vasp: Solving a cell motility paradox. CURR BIOL , 12 (12) R417 - R419.

Cramer, LP; Briggs, LJ; Dawe, HR; (2002) Use of fluorescently labelled deoxyribonuclease I to spatially measure G-actin levels in migrating and non-migrating cells. CELL MOTIL CYTOSKEL , 51 (1) 27 - 38.

Dawe, H; Cramer, L; (2002) Regulation of polarized, persistent movement during cell migration; role of actin filament disassembly. In: MOLECULAR BIOLOGY OF THE CELL. (pp. 32A - 32A). AMER SOC CELL BIOLOGY

Rosenblatt, J; Baum, B; Blyth, J; Cramer, LP; (2002) Myosin and actin are required for centrosome separation during prophase. In: MOLECULAR BIOLOGY OF THE CELL. (pp. 51A - 51A). AMER SOC CELL BIOLOGY

2001

Cramer, LP; (2001) Mechanism of formation of graded polarity actin filament bundles in migrating chick fibroblasts. In: MOL BIOL CELL. (pp. 423A - 423A). AMER SOC CELL BIOLOGY

Dawe, H; Cramer, L; (2001) The ratio of G-actin to F-actin in the lamellipodium of fibroblasts is relatively low in migrating cells and high in non-migrating cells. In: MOL BIOL CELL. (pp. 422A - 423A). AMER SOC CELL BIOLOGY

Rosenblatt, J; Raff, MC; Cramer, L; (2001) An epithelial cell destined for apoptosis signals its neighbors to extrude it by an actin/myosin-dependent mechanism. In: MOL BIOL CELL. (pp. 401A - 401A). AMER SOC CELL BIOLOGY

Rosenblatt, J; Raff, MC; Cramer, LP; (2001) An epithelial cell destined for apoptosis signals its neighbors to extrude it by an actin- and myosin-dependent mechanism. CURR BIOL , 11 (23) 1847 - 1857.

2000

Cramer, LP; (2000) Myosin VI: Roles for a minus end-directed actin motor in cells. J CELL BIOL , 150 (6) F121 - F126.

Cramer, LP; Briggs, LJ; (2000) A cell-staining method that reports cellular g-actin concentration. In: MOL BIOL CELL. (pp. 562A - 562A). AMER SOC CELL BIOLOGY

Rosenblatt, JS; Raff, MC; Cramer, LP; (2000) Actin/myosin-based cell contraction drives extrusion of apoptotic cells from epithelia. In: MOL BIOL CELL. (pp. 294A - 294A). AMER SOC CELL BIOLOGY

1999

Cramer, LP; (1999) Relative importance of actin filament disassembly during lamellipodium protrusion in motile tells. In: MOL BIOL CELL. (pp. 27A - 27A). AMER SOC CELL BIOLOGY

Cramer, LP; (1999) Role of actin-filament disassembly in lamellipodium protrusion in motile cells revealed using the drug jasplakinolide. CURR BIOL , 9 (19) 1095 - 1105.

Cramer, LP; (1999) Organization and polarity of actin filament networks in cells: implications for the mechanism of myosin-based cell motility. CELL BEHAVIOUR: CONTROL AND MECHANISM OF MOTILITY (65) 173 - 205.

1997

Cramer, L; Roche, S; SupertiFurga, G; Aasland, R; Verrijzer, P; Izaurralde, E; ... Carlton, M; + view all (1997) A selection of interesting papers that were published in the two months before our press date in major journals most likely to report significant results in cell biology. CURR OPIN CELL BIOL , 9 (6) 757 - 763.

Cramer, LP; (1997) Molecular mechanism of actin-dependent retrograde flow in lamellipodia of motile cells. Front Biosci , 2 d260 - d270.

Cramer, LP; Mitchison, TJ; (1997) Investigation of the mechanism of retraction of the cell margin and rearward flow of nodules during mitotic cell rounding. MOL BIOL CELL , 8 (1) 109 - 119.

Cramer, LP; Siebert, M; Mitchison, TJ; (1997) Identification of novel graded polarity actin filament bundles in locomoting heart fibroblasts: Implications for the generation of motile force. J CELL BIOL , 136 (6) 1287 - 1305.

1996

Cramer, LP; Sievert, M; Mitchison, TJ; (1996) Novel actin filament polarity in migrating fibroblasts: Implications for the mechanism of force generation during cell migration. In: MOL BIOL CELL. (pp. 3250 - 3250). AMER SOC CELL BIOLOGY

Mitchison, TJ; Cramer, LP; (1996) Actin-based cell motility and cell locomotion. CELL , 84 (3) 371 - 379.

1995

CRAMER, LP; MITCHISON, TJ; (1995) MYOSIN IS INVOLVED IN POSTMITOTIC CELL SPREADING. J CELL BIOL , 131 (1) 179 - 189.

1994

CRAMER, LP; MITCHISON, TJ; THERIOT, JA; (1994) ACTIN-DEPENDENT MOTILE FORCES AND CELL MOTILITY. CURR OPIN CELL BIOL , 6 (1) 82 - 86.

1993

CRAMER, L; MITCHISON, TJ; (1993) MOVING AND STATIONARY ACTIN-FILAMENTS ARE INVOLVED IN SPREADING OF POSTMITOTIC PTK2 CELLS. J CELL BIOL , 122 (4) 833 - 843.

1992

Cramer, LP; Cutler, DF; (1992) Sorting between exocytic pathways in PC12 cells. In: Magee, AI and Wileman, T, (eds.) Protein targeting: a practical approach. (200 - 221). IRL press at Oxford University Press: Oxford; New York.

CRAMER, LP; MITCHISON, TJ; (1992) ACTIN FILAMENT DYNAMICS IN SPREADING MITOTIC CELLS. In: MOL BIOL CELL. (pp. A272 - A272). AMER SOC CELL BIOLOGY

1990

CUTLER, DF; CRAMER, LP; (1990) SORTING DURING TRANSPORT TO THE SURFACE OF PC12 CELLS - DIVERGENCE OF SYNAPTIC VESICLE AND SECRETORY GRANULE PROTEINS. J CELL BIOL , 110 (3) 721 - 730.

This list was generated on Sun Oct 26 06:56:22 2014 GMT.