Cell Biology and Biophysics
Jan Ellenberg
Head of Cell Biology and Biophysics Unit
The cell is the basic unit of life. Interestingly, living cells occupy the precise midpoint between the molecular and macroscopic scales. Thus, in order to understand how organisms are built and how they function, we need to understand the molecular mechanisms and physical principles that give rise to cellular organisation and function.
All cells (including prokaryotes) are organised into functional domains, each with different molecular compositions. In addition, eukaryotes have compartments such as the nucleus, the cytoskeleton and the endomembrane system. These compartments are permanently renewed by mechanisms that are still poorly understood.
Research in the Cell Biology and Biophysics Unit focuses on the mechanisms and principles that underlie the organisation and function of these different compartments and the distribution of specific molecules to each cellular sub-system. Cell biologists and physicists at EMBL are therefore trying to define the role of targeting events, as well as that of more complex self-organisation processes in organising cellular space. These principles are best understood at transitions when the organisation of the cell undergoes dramatic changes to carry out new functions. This is the case when cells divide, or when they change their fate during the development of the organism to form specific tissues and organs. Both opportunities are exploited in the unit.
| Antony Team | Cellular electron tomography of cells |
| Ellenberg Group | Functional dynamics of nuclear structure during the cell cycle |
| Gilmour Group | The role of collective cell migration during organ morphogenesis |
| Häring Group | Chromosome structure and dynamics |
| Hufnagel Group | Dynamics of cell growth and tissue architecture |
| Kaksonen Group | Dynamics of membrane trafficking |
| Lénárt Group | Cytoskeletal dynamics and function in oocytes |
| Nédélec Group | Cellular architecture |
| Neveu Group | Systems biology of stem cell differentiation |
| Pepperkok Team | Membrane traffic in the early secretory pathway |
| Schultz Group | Chemical cell biology |
As a cell prepares to divide, all the microtubules suddenly depolymerise to reassemble into the mitotic spindle. At the same time, the nucleus is disassembled, mitotic chromosomes are formed, the Golgi complex fragments and membrane traffic ceases. After segregation of the genome is achieved, cellular organisation is re-established. Thus every cell cycle provides the opportunity to study the principles of the biogenesis of cellular compartments. Similarly, during development, when progenitor cells differentiate into new cell types, not only do the daughter cells receive a complement of chromosomes and organelles from the parent cell, but the genetic program is changed. A reorganisation of cellular architecture takes place, guided by rules that we begin to unravel. The elucidation of such rules and principles is a major challenge in contemporary biology.
The areas that we are presently concentrating on are membrane trafficking, cytoskeletal networks and chromosomes and the nucleus and their role in mitosis and meiosis as well as in development. New directions are therefore being explored at the interface between cell and developmental biology to understand how the cell organisation and collective cell behaviour leads to organ formation. Physicists and chemists working together with biologists are trying to elucidate the fundamental rules that govern dynamic cell organisation and function while developing new instruments and tools. Novel developments in microscopy and computer simulations are a particular strength of the unit.
Jan Ellenberg
Head of the Cell Biology and Biophysics Unit