Associate Professor, BCMB
Office: Mossman 415, (865-974-3612)
Lab: Mossman 420B
Lab Website: daslabpombe.com
Ph.D. Biosciences, Indian Institute of Technology, Mumbai, India
Cells are highly efficient machines that operate with great precision to promote proliferation and function. Complex cellular processes operate in an error-free manner, largely due to intricate regulatory patterns that precisely organize multi-step processes in time and space. The Das Lab investigates the precise regulatory patterns ensure proper cell shape and division. Studies from our lab as well as others have shown that these regulatory patterns involve self-organization of higher-order molecular networks. We explore these molecular networks using mainly the single-celled eukaryotic model system Schizosaccharomyces pombe, or fission yeast. Fission yeast cells have a well-defined shape and growth pattern, and divide by actomyosin-ring-dependent cytokinesis, making it an excellent model system for our investigations. Our research employs broad interdisciplinary approaches in cell and molecular biology and genetics, with special expertise in quantitative live-cell imaging. We also collaborate closely with engineers and mathematicians to build predictive models of these regulatory mechanisms. The research in our lab is funded by the National Science Foundation (Molecular and Cellular Biosciences) and National Institutes of Health/NIGMS. Following are the current projects in the lab.
Defining the Rules for Cell Polarization
Cell shape establishment and maintenance is critical to cell function and survival. Eukaryotic cells display a variety of distinct cell shapes, thus enabling distinct cellular functions. Emerging research, including our own, reveals that the fundamental proteins involved in cell shape/polarity establishment and maintenance are broadly conserved. However, the precise regulatory mechanisms that control these proteins differ, resulting in diverse cell shapes. Our current research investigates the molecular details of these diverse regulatory modules in the control of cell polarity.
Organization of Cytokinetic Events
The final step in cell division is cytokinesis, during which the cytoplasm divides into two after nuclear division. Cytokinesis involves multiple steps that are spatiotemporally organized for successful cell separation. We have found that once the actomyosin ring forms, polarization and membrane trafficking events are critical for successful completion of different cytokinetic steps. These polarization and membrane trafficking events show diverse spatiotemporal patterns throughout different cytokinetic steps. It is unclear how these polarization and trafficking patterns undergo spatiotemporal transitions to organize sequential cytokinetic events. Our data indicate that spatiotemporal signaling patterns at the division site regulate polarization and help to organize different cytokinetic events. Current projects in the lab are focused on unraveling the molecular details of how these spatiotemporal patterns emerge and how they lead to successful cytokinesis.
For more details please visit the Das Lab website.
(§Graduate students, #Undergraduate students, †High School students)
- Onwubiko UN, Rich-Robinson J§, Mustaf RA†, Das ME. 2020. Cdc42 promotes Bgs1 recruitment for septum synthesis and glucanase localization for cell separation during cytokinesis in fission yeast. Small GTPases, Mar 22:1-8.
- Hercyk B, Rich J, Mitoubsi A, Harrell M, Das M. 2019. A novel interplay between GEFs orchestrates Cdc42 activation in cell polarity and cytokinesis. Journal of Cell Science2019, 132:jcs236018-jcs236018.
Work Featured in: preLights.
- Hercyk B and Das M. 2019. F-BAR Cdc15 Promotes Gef1-mediated Cdc42 Activation During Cytokinesis and Cell Polarization in pombe. Genetics, 2019, 213 (4): 1341-1356.
- Hercyk B and Das M. 2019. Rho Family GTPases in Fission Yeast Cytokinesis. Communicative and Integrative Biology, Oct 21;12(1):171-180.
- Hercyk B, Onwubiko UN, Das M. 2019. Coordinating Septum Formation and the Actomyosin Ring during Cytokinesis in Schizosaccharomyces pombe. Molecular Microbiology, Dec;112(6):1645-1657.
- Onwubiko UN, Mlynarczyk PJ, Wei B, Habiyaremye J#, Clack A#, Abel SM, Das ME. A Cdc42 GEF, Gef1, through endocytosis organizes F-BAR Cdc15 along the actomyosin ring and promotes concentric furrowing. Journal of Cell Science2019 132: jcs223776 doi: 10.1242/jcs.223776 Published 28 February 2019. PMID: 30709916.
Work Featured in: Editor’s highlight, Journal of Cell Science
- Wei B, Hercyk BS, Habiyaremye J#, Das M. 2017. Spatiotemporal analysis of cytokinetic events in fission yeast. JoVE, 120. PMID:28287547
- Wei B, Hercyk BS, Mattson N, Mohammadi A#, Rich J#, DeBruyne E#, Clark MM#, Das M. 2016. Unique Spatiotemporal Activation Pattern of Cdc42 by Gef1 and Scd1 Promotes Different Events during Cytokinesis. Molecular Biology of the Cell, 27(8):1235-45; PubMed PMID: 26941334.
Work Featured in: Molecular Biology of the Cell, ASCB newsletter.