This administrative supplement request seeks support to purchase a Nikon A1R Live Cell Resonant Dual Scanner Microscope to support NIGMS funded research by Dr. David Greenstein (grant #5R01 GM057173-17) and Dr. Melissa Gardner (grant #R35-GM126974) in the Genetics, Cell Biology, and Development department at the University of Minnesota. The Gardner Laboratory uses a combination experimental and computational approach to dissect molecular mechanisms for how microtubule lengths are regulated inside of cells, and for how force signaling acts to ensure proper chromosome segregation during mitosis. We use biophysical computational modeling to better integrate and understand our experimental observations, make new experimental predictions, and to test whether our proposed cellular mechanisms are physically reasonable. Overall, we are a cellular biophysics laboratory that combines cell biology tools with biophysical methods to shed new light on the regulation of microtubule dynamics, and to dissect forces in mitosis. Achieving the goals described in this application will provide mechanistic insights into how molecular-scale changes in microtubule structure could regulate cellular- scale changes in microtubule-associated protein localization and binding, as well as how changes in chromosome structure and stiffness could affect cellular-level tension signaling during mitosis. In particular, this application will advance our understanding of: 1) how microtubule structure can alter protein binding, and vice versa, 2) how the cell reads out and responds to nuanced tension signaling during mitosis, and 3) how a disease process such as cancer may alter tension signaling during mitosis, and the specific impact of aneuploidy, which is a hallmark of cancer cells, on centromere stiffness and tension signaling during mitosis.
Mitosis is the process by which duplicated sister chromosomes are evenly distributed to identical daughter cells, and in cancer cells, improper chromosome segregation during mitosis (e.g., such that chromosomes are unevenly distributed between daughter cells) is widely observed, and has been linked to poor prognosis, including decreased overall survival time and fewer treatment free years. In this study, we will make use of physical principles and advanced microscopy to evaluate chromosome stiffness and tension inside of living cells, and to dissect the role of microtubule structure in the targeting of microtubule-associated proteins. The results generated from our studies will be applicable both towards better understanding the fundamental biophysics of cell division, and also towards providing mechanistic information to shed light on current cancer therapies.