Rob Phillips
Professor of Applied Physics and Mechanical Engineering; Option Representative for Biochemistry and Molecular Biophysics (BMB)

B.A., University of Minnesota, 1986; Ph.D., Washington University, 1989

1200 East California Boulevard
Pasadena, CA 91125
MC 114-96

(626) 395-3374
(626) 583-4963 (fax)

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Research

Professor Phillips' research group's efforts are concerned with the physical biology of the cell. Our research uses physical approaches to understand the structure and function of living organisms and the macromolecular complexes that make them up. With increasing regularity, experiments on biological systems are quantitative. As a result, the models set forth to greet these experiments must themselves be quantitative. We are interested in a number of different case studies involving the mechanical response of cells and the machines within them.

One class of problems of particular interest involves the strong bending of DNA. Strongly bent DNA is a fact of life. Examples of this range from the packing of DNA in viruses and eukaryotic cells to the way in which genes are controlled in the process of transcriptional regulation. Our group is engaged in both experiments and model building aimed at reconciling the way DNA bending is viewed in both the in-vitro and in-vivo settings. A second class of problems surrounds the question of how cells sense mechanical forces. The mechanism of mechanosensation in bacteria is mediated by proteins known as mechanosensitive ion channels. Here too, we are engaged in the development of predictive models and experiments aimed at testing these models.

Detailed information regarding the following research topics can be found at the Phillips Group website.

Mechanics of macromolecules and macromolecular assemblies

• Ion channels gated by mechanical tension
  
• Physics of DNA packaging and ejection in viruses
  
• Sequence dependence of DNA elasticity

Dynamics in fluctuating environments

• BioNEMS: biofunctionalized cantilevers
  
• Colloidal free expansion
  
• Maximum entropy and non-equilibrium physics
  
• Physics of transcriptional regulation

Selected Publications

Transcriptional Regulation by the Numbers 1: Models (with L, Bintu, N. E. Buchler, H. G. Garcia, U. Gerland, T. Hwa, and J. Kondev), Current Opinion in Genetics & Development 15(2):116-124 (2005)

Transcriptional Regulation by the Numbers 2: Applications (with L. Bintu, N. E. Buchler, H. G. Garcia, U. Gerland, T. Hwa, J. Kondev, and T. Kuhlman), Current Opinion in Genetics & Development 15(2):125-135 (2005)

Exact Theory of Kinkable Elastic Polymers (with P. A. Wiggins and P. C. Nelson), Physical Review E, 71:021909 (2005)

Membrane-Protein Interactions in Mechanosensitive Channels (with P. Wiggins), Biophys. J., 88:880-902 (2005)

Forces During Bacteriophage DNA Packaging and Ejection (with P. K. Purohit, M. M. Inamdar, P. D. Grayson, T. M. Squires, and J. Kondev), Biophys. J., 88: 851-866 (2005)

Mechanics of Biological Nanotechnology (with P. K. Purohit and J. Kondev), Handbook of Nanotechnology, Springer, edited by B. Bhushan (2004)

Force Steps During Viral DNA Packaging? (with P. K. Purohit and J. Kondev), Journal of Mechanics and Physics of Solids, 51 (11-12):2239-2257 (2004)

Analytic Models for Mechanotransduction: Gating a Mechanosensitive Channel (with P. Wiggins), Proc. Nat. Acad. Sci., 101:4071-4076 (2004)

Mechanics of DNA Packaging in Viruses (with P. K. Purohit and J. Kondev), Proc. Nat. Acad. Sci., 100:3173 (2003)

Crystals, Defects and Microstructures, Cambridge University Press (2001)