This project seeks to understand how cells control their shape and movement using synthetic biology tools. Cell movement is essential for single cells to hunt and mate and for the correct development and function of multicellular organisms. Sheet-like protrusions called lamellipodia are the engines that power and guide this motility. However, the rules of their formation are not understood. Similar to ant colonies where no individual is ?in charge?, and the overall behaviors of a colony depends on simple rules of local interaction between ants, many aspects of cell biology are dominated by local rules of interaction between proteins. This project seeks to define these rules of protein-protein interactions by constructing lamellipodia from synthetic, designer proteins whose patterns of interaction can be built to order. This work is a collaboration between an expert in cell shape/movement (Orion Weiner at the University of California-San Francisco) and an expert in protein design (Dek Woolfson at the University of Bristol). STEM workforce diversity will be enhanced through multiple synergistic activities. (1) reforming the grad school admissions process to make it more inclusive; (2) research opportunities for high school students from underrepresented groups and hands-on science demonstrations for teachers and elementary/middle/high-school students; (3) engagement of a wider audience by presentations to the general public through the Exploratorium, Science Festival Discovery Days, and Science CafÃ©s; (4) Engagement of policy makers and local and national industries to advocate for the use of designed proteins and systems in biotechnology; (5) interdisciplinary training for three postdoctoral fellows and five high school students. This work will strengthen links between US and UK labs and between the NSF and the BBSRC.
Weiner?s lab recently discerned the nanoscale organization of a key actin nucleator that suggests a self-organizing template for lamellipodia formation. These templates are not sufficiently understood to manipulate directly their biophysical parameters (such as linearity vs. curvature, rigidity, dynamics, etc.) and to probe fully the relation between actin nucleator oligomerization and cell shape and function. A powerful alternative to the typical genetic and biochemical approaches would be to build actin regulators from scratch, so that the molecular logic of cell shape and movement can be probed systematically. To do this, protein engineering and de novo protein design (Woolfson lab) will be used to generate synthetic proteins that assemble with defined geometries at membranes to nucleate actin, guided by our knowledge of the native system. These synthetic systems will be tested for their ability to support lamellipodial formation in vivo using cells defective in lamellipodia formation and ultimately in complete reconstitutions. These studies will advance protein design towards in-cell application, and, in turn, they will help define the molecular logic of cell shape and movement.
This collaborative US/UK project is supported by the US National Science Foundation and the UK Biotechnology and Biological Sciences Research Council.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.