A collaboration
between Lehigh University
physicists and University
of Miami biologists
addresses an important fundamental question in basic cell biology: How do
living cells figure out when and where to grow?
The study,
Oscillatory Dynamics of Cdc42 GTPase In The Control of Polarized Growth,
appears in Science Express.
Assistant Professor
Dimitrios Vavylonis and graduate
student Tyler Drake joined University
of Miami researchers to
learn that protein Cdc42 begins the ballet of proteins that change cell
polarity, by oscillating throughout the cellular membrane of new cells. By
changing polarity, Cdc42 regulates shape, structure, and function in yeast
cells. This oscillatory mechanism may be a general strategy among all
self-organizing biological systems, not just simple yeast.
Researchers used
fluorescent markers to tag each of the many proteins involved, observing the
protein oscillate, switching sides about every five minutes. The fluctuations
provide an adaptable mechanism for cells to control their size and structure in
the fast-changing environment within.
The findings
demonstrate just part of the complex process of cell growth and
differentiation, but mark how advanced the science of biophysics has become.
Only recently has the clear imaging and monitoring of protein activity become
possible at the minute sizes and shortened time scales of individual cell
maturation.
Vavylonis’s
research has for years explored the way the cellular cytoskeleton organizes and
functions. In collaboration with biologists and computer scientists, his team
uses physics to study, analyze, and model the physical properties of these
adaptive biological materials.
The study was funded by the National Science
Foundation, the National Institutes of Health, and by individual university
groups including a Lehigh Class of 1968 Junior Faculty Fellowship and a Sigma
Xi grant to Drake.