Date : 06/05/2011

Internship proposal for : Master 1 or Master 2

Laboratory
Cytoskeleton architecture and cell polarization
UMR-S 787 UPMC, INSERM
105 boulevard de l'Hôpital 75014 PARIS
Website : http://www.myologygroup.net/Home/gomes
Main discipline : Cell Biology
Lab director : David Sassoon

Mentor
Edgar Gomes
email : This e-mail address is being protected from spam bots, you need JavaScript enabled to view it
phone : 01 40 77 96 87

Subjects
1.: Nucleus
2.: Cytoskeleton
3.: Cell Migration

Tools and methodologies
1.: Time-lapse video microscopy
2.: Molecular Biology
3.: Biochemistry

Summary of lab's interests

Position of the nucleus is important for cellular activities such as cell division, cell migration and multicellular organism development. The cytoskeleton plays an important role in nuclear positioning either by anchoring or moving the nucleus within the cell. In our lab we are interested in understanding how does the cytoskeleton regulates nuclear positioning and what is the role of nuclear positioning during cell migration and myofiber formation. We are also curious to know how mutations in proteins associated with muscular dystrophies interfere with nuclear position during myofiber formation.

Summary of project

Cell migration is required for efficient metastasis of tumors. We recently found that migrating cells position their nuclei away from the front of the cell prior to migration (1). In addition, we also found that inhibition of nuclear positioning blocks cell migration. The nucleus is connected to the actin cytoskeleton by nesprins, a family of nuclear envelope (NE) proteins, and this connection is required for nuclear movement (2). Nesprin localization at the NE requires SUN proteins, another family of NE proteins and these proteins are required for nuclear movement and cell migration. We performed a siRNA screen against predicted nuclear envelope protein and identified several molecules required for nuclear movement and cell migration (3). We propose to study how these proteins are involved in nuclear positioning during cell migration. Specifically, we are studying how these proteins interfere with the connection of the nucleus with the cytoskeleton via nesprin and SUN proteins. We use state-of-the-art microscopy techniques (multicolor time-lapse fluorescent microscopy, photo-activation and photoswitchable techniques, fluorescence recovery after photobleaching - FRAP) combined with molecular biology, biochemistry and micromanipulation (microinjection) approaches to address this process both in vitro and in vivo. The mechanisms of nuclear positioning during cell migration that we will identify are potential targets for therapies to inhibit abnormal cell migration that occur during cancer metastasis. References: 1. Gomes, E. R., Jani, S., and Gundersen, G. G. (2005). Nuclear movement regulated by Cdc42, MRCK, myosin, and actin flow establishes MTOC polarization in migrating cells. Cell 121, 451-63. 2. Luxton, G. W. G.*, Gomes, E. R.*, Folker, E. S., Vintinner, E., and Gundersen, G. G. (2010). Linear Arrays of Nuclear Envelope Proteins Harness Retrograde Actin Flow for Nuclear Movement. Science 329, 956-959. * co-first author 3. Jegou, T. Pinto, J., Osorio, D, Gomes E.R. in revision