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Jenny Gallop

gallop2014Jenny Gallop PhD, Wellcome Trust Career Development Fellow, Member of the Department of Biochemistry.

Gallop Group websiteEurope PMC | Pubmed

 

Prospective PhD students and postdocs are welcome to apply with a covering email and CV to Jenny Gallop.

 

Membranes, actin and morphogenesis

2016 GallopHow do cells generate and maintain their characteristic shapes? The cell membrane, as the boundary of the cell, is moulded into shape by dynamic remodelling of its links to the actin cytoskeleton during cell division, polarisation, movement, differentiation and for everyday housekeeping.

In disease, the actin machinery is hijacked by invading pathogens. Some actin regulators are overexpressed and redeployed during cancer metastasis, and control of the actin cytoskeleton can be disrupted in genetic diseases, causing intellectual disability, kidney dysfunction and other problems.

We are studying how actin filaments polymerise at two types of specialised structures at the cell membrane: filopodia, which are finger-like protrusions, and endocytic vesicles, which bud inwards to bring in components from the membrane or environment. We have developed model systems using phospholipid bilayers and frog egg extracts that allow us to follow the molecular events of actin self-assembly in different contexts. By focusing on unusual predictions from these in vitro assays, we work out how the actin cytoskeleton is regulated by imaging cells in accessible, native developmental contexts in fruit fly and frog embryos.

Selected publications:

• Watson JR et al (2016) Investigation of the Interaction between Cdc42 and Its Effector Toca1: Handover of Cdc42 to the actin regulator N-WASP is facilitated by differential binding affinities. J Biol Chem. 291(26):13875-90.

•  Walrant A et al. (2015) Triggering actin polymerization in Xenopus egg extracts from phosphoinositide-containing lipid bilayers. Methods Cell Biol 128: 125–147.

• Gallop JL, Walrant A, Cantley LC, Kirschner MW. (2013) Phosphoinositides and membrane curvature switch the mode of actin polymerization via selective recruitment of toca-1 and Snx9. Proc Natl Acad Sci 110: 7193-7198

• Lee K*, Gallop JL*, Rambani K, Kirschner MW. (2010) Self-assembly of filopodia-like structures on supported lipid bilayers. Science, 329:1341-1345.

• Gallop JL*, Jao CC*, Kent HM, Butler PJ, Evans PR, Langen R, McMahon HT. (2006) Mechanism of endophilin N-BAR domain-mediated membrane curvature. EMBO J. 25: 2898-2910.

• Gallop JL, Butler PJ, McMahon HT. (2005) Endophilin and CtBP/BARS are not acyl transferases in endocytosis or Golgi fission. Nature. 438: 675-678.

• McMahon HT, Gallop JL. (2005) Membrane curvature and mechanisms of dynamic cell membrane remodelling. Nature. 438: 590-596.

*joint first authors

groupGallop2015

Plain English

During embryonic development, a single cell divides many times generating the cells that specialize and move around to arrange themselves into the final organism through a process called morphogenesis. For the cells to get to the right locations they have to sense where they are going, exert force on their surroundings and target proteins on the membrane surface to their correct destinations. The formation of polymers of a protein called actin inside cells are important for all these functions.

Actin polymerisation is closely connected with the cell membrane, which forms the interface between the inside of the cell and its environment. We are working on two uses of actin: the formation of finger-like protrusions called filopodia, that are important for sensing the environment, and in endocytosis, which cells use to take things up and control what is in their membranes. Finding out how actin polymerisation is triggered during filopodia formation and endocytosis will help our understanding of disease and suggest ways in which we might be able to intervene. Filopodia are important for learning and memory and are used by cancer cells for metastasis. The endocytic machinery can be hijacked by pathogens to gain access to cells and actin filaments are also exploited by pathogens to reach other cells and increase infection. 

To examine how actin polymerisation is controlled by cells we generate filopodial and endocytic actin structures in test tubes using artificial membranes and cell extracts to mimic the natural interface between the cell membrane and the cytoplasm. We then study the processes that we find in embryos to find how the molecular machines are employed during morphogenesis.

Co-workers

Frédéric Daste • Ulrich Dobramysl • Helen Fox • Jonathan Gadsby • Iris Jarsch • Julia Mason • Benjamin Richier • Hanae Shimo • Vasja Urbancic