Pushkar Lele

Assistant Professor

lele_2015

Office: 241 CHEN
Phone: 979.458.2790
Email: plele@tamu.edu

Research Website

Research Interests

About Pushkar Lele Research Group:

We combine sensitive biophysical techniques such as single-molecule fluorescence and force-spectroscopy with mechanistic modeling and molecular genetics to study bacterial motility, adaptability and antibiotic resistance.

Cell Mechanics

We are studying the physics underlying mechanical triggering of cell-development by mechanosensitive enzymes. Our recent work identified the enzymes responsible for detecting mechanical signals in transmembrane macromolecules (Lele et al., PNAS 2013). Currently, we focus on determining how individual cells engineer systems that are responsive to mechanical forces, and regulate biochemical signaling networks. These projects are crucial in developing counters against colonization and infections.

For these projects, we employ novel approaches based on optical-tweezers, laser dark-field microscopy and fluorescence microscopy to probe the dynamics of function, as well as structure, in individual molecular motors (please visit group page).

Biofluid Dynamics and Antibiotic Resistance

Bacteria possess well-known abilities to respond to environmental signals and rapidly adapt. Motility or cell-swimming helps bacteria respond to chemical signals in their native environment through a process known as chemotaxis.

In our recent work, we have uncovered a paradox associated with cell-motility (Lele et al., Nature Physics,2015). In cells carrying single flagella (helical filaments that linearly couple flagellar-motor rotation to the cell's translational motion), motors exhibit torque-anisotropy with respect to direction. However, corresponding swimming-speed data appear inconsistent with time-reversibility of Stoke's equations, which form the cornerstone of current understanding of motion at low-Reynolds numbers. To understand the basis for such differences, we are investigating how biopolymer properties govern motile responses. Other projects focus on the rise of antibiotic resistance through cell-cell hydrodynamic interactions.

Biological/Soft-Matter Assembly

Self-assembly drives the formation of all biological systems, including a variety of nano-devices within living cells. Bacteria are colloids and brilliant nanotechnologists! One of the significant problems we are interested in solving are the unknown mechanisms underlying rapid self-assembly, in live cells, which govern short-time cell-adaptation. Lessons learnt from nature will be extended to develop new nanotechnologies for building synthetic bio-sensors and actuators, as well as drug delivery systems.

Awards & Honors

  • Best poster award, 20th Annual Boston Bacterial Meeting, Cambridge, MA (2014).
  • Semifinalist, Burroughs Wellcome Fund Careers at the Scientific Interface (2013).
  • Robert Macnab award for Outstanding presentation by a young investigator, Bacterial locomotion and Signal transduction Conference, New Orleans, LA (2011).
  • Best poster award, 11th Tiger-Hen-Hawk (Princeton-Delaware-Lehigh) Rheology Symposium, Newark, DE (2008).

Education

  • Postdoctoral Research, Harvard University, 2015
  • Ph.D. Chemical Engineering, University of Delaware, 2010
  • B.E. Chemical Engineering, Mumbai University Institute of Chemical Technology, India, 2005

Selected Publications

P. P. Lele, T. Roland, A. Shrivastava, Y. Chen, H. C. Berg, “The flagellar motor of Caulobacter crescentus generates more torque when a cell swims backwards”, Nature Physics.

P. P. Lele, A. Shrivastava, T. Roland, H. C. Berg, “Response thresholds in bacterial chemotaxis”, Science Advances, in press.

A. Shrivastava, P. P. Lele, H. C. Berg, “Gliding is driven by a rotary motor”, Current Biology (2015), 25 (3), 338-341.

P. P. Lele & H. C. Berg, “Switching of Bacterial Flagellar Motors Triggered by Mutant FliG”, Biophysical Journal (2015), 108 (5), 1275-1280.

P. P. Lele, Basarab G. Hosu, H. C. Berg, “Dynamics of mechanosensing in the bacterial flagellar motor”, Proceedings of the National of Academy of Sciences, USA (2013), 110 (29), 11839-11844.

P. P. Lele, R. W. Branch, V. Nathan, H. C. Berg, “Mechanism for adaptive remodeling of the bacterial flagellar switch”, Proceedings of the National of Academy of Sciences, USA (2012), 109 (49), 20018-20022.

P. P. Lele, J. W. Swan, J. F. Brady, N. J. Wagner, E. M. Furst, “Colloidal diffusion and hydrodynamic screening near boundaries”, Soft Matter(2011), 7, 6844-6852.

P. P. Lele, E. M. Furst, “Assemble-and-Stretch method for creating two- and three-dimensional structures of anisotropic particles,” Langmuir(2009), 25, 8875-8878.