Jonathan “Josh” Earl Baker, Ph.D.
Department of Biochemistry, School of Medicine
University of Nevada Reno, Reno, Nevada
Phone: (775) 784-4103 Fax: (775) 784-1419
1987 B.S. Hamline University, St. Paul, Minnesota
Physics, Cum Laude
1992-1994 University of Minnesota
Graduate program in Physics
1999 Ph.D. University of Minnesota (David D. Thomas)
Biochemistry, Biophysics, and Molecular Biology; Physics minor
Courses completed: Educational psychology, Introduction to teaching, Teaching science.
1985, Teaching Practicum: Physics (40 hours) Roseville Senior High, Roseville, MN
1987, Instructor: Circuit analysis (15 lectures, 5 labs) Hamline University.
1987, Instructor: General Physics (9 labs) Hamline University.
1994-1995, Teaching Assistant: Biochemistry (3 recitations) U of M.
1994-1995, Teaching Assistant: Biochemistry (3 recitations) U of M.
2006-2009, Coordinator: Curriculum Coordinator Medical Biochemistry
2007, Instructor: BCH 707: Protein Structure Function (6 contact hours/year)
2005-present, Instructor: PCB 610: Medical Cell Biology (6 contact hours/year)
2007-present, Instructor: BCH 601: Medical Biochemistry (30 contact hours/year)
2008-present, Instructor: CMB 710: Molecular Cell Biology (4 contact hours/year)
2009, Instructor: BCH 794: Supramolecular Structures (6 contact hours/year)
1987-1988, Computer Programmer: Honeywell, St. Louis Park, MN
1988-1993, Systems Analyst: David Mitchell and Associates, St. Paul, MN
1999-2003, Postdoctoral Fellow: University of Vermont (David Warshaw).
2004-2010, Assistant Professor: University of Nevada, Reno, Dept of Biochemistry
2010-present, Associate Professor: University of Nevada, Reno, Dept of Biochemistry
SERVICE, SOCIETIES, HONORS AND AWARDS
1992-2000, Board of Church and Society United Methodist Church, Washington, D.C.
1994, Graduate Fellowship BBMB, University of Minnesota
1995-1996, National Science Foundation Training Grant
2000-2002, National Institutes of Health Training Grant
1993-present, Biophysical Society Member
2006-2007, Organizer/Chair Motility Subgroup Biophysical Society
2006-2010, Department of Biochemistry Personnel Committee
2006-2008, Course Coordinator BCH601: Medical Biochemistry
2006-present, Medical School Admissions Committee
2009-present, Co-Chair Medical School Honors Council
2010, Board of Regents Rising Researcher Award
Review for Biophysical Journal, Biochemistry, Journal Biological Chemistry, Journal Theoretical Biology, Proceedings National Academy of Sciences
We use single molecule techniques (TIR fluorescence microscopy and optical traps) to study how mechanoenzymes like actin and myosin transfer chemical free energy to mechanical work and inversely how they convert mechanical signals into chemical responses. We are particularly interested in understanding how the mechanochemical behaviors of single molecules scale up to the mechanochemical behaviors of bulk cellular systems. We use mathematical and computer models to integrate our multi-scale experimental studies, developing self-consistent descriptions of muscle contraction, intracellular transport, and mechanical signal transduction.
INVITED SYMPOSIUM PRESENTATIONS
2000 Gordon Conference on Theoretical Biology and Biomathematics (session chair). Tilton, NH.
2001 Alpbach Workshop on Molecular Motors. Alpbach, Austria.
Actin-myosin mechanochemistry: Single molecule and ensemble studies.
2001 Fifth International Muscle Energetics Conference. Burlington, VT.
Actin movement and actomyosin ATPase kinetics.
2001 New York State Section American Physical Society 83rd Topical Symposium, Albany, NY.
Biophysical chemistry of a molecular motor.
2002 Gordon Conference on Muscle:Contractile Proteins. New London, NH.
Single molecule comparative mechanochemistry.
2002 Tenth Annual Meeting of the New England Smooth Muscle Society. Burlington, VT.
Mechanochemistry of a minus-insert smooth muscle heavy meromyosin.
2003 McGill University Beer Seminar. Montreal, Quebec, Canada. A Common Mechanism for Myosin V Processivity and Smooth Muscle Latch.
2004 Mathematical Biosciences Institute Workshop on Signal Transduction II: Muscles and Motility. Columbus, OH. Free energy transduction by chemical motors.
2004 Proteomics Workshop IV: Molecular Machines. Institute for Pure and Applied Mathematics (IPAM). Los Angeles, CA. The energetics of chemical motors.
2005 Biophysical Society Motility Subgroup: A Panoply of Motors. Long Beach, CA. Exploring the multiple kinetic pathways for myosin V processivity.
2006 Sixth International Muscle Energetics Conference. Banff, Alberta Canada.
The macroscopic mechanochemistry of muscle.
2006 FASEB smooth muscle. Snowmass, CO.
Actin binding in relation to muscle force and motion generation.
2008 ACS National Meeting. Philadelphia, PA
The collective mechanics of myosin in muscle.
2008 University of Northern Texas. Fort Worth, TX.
The collective dynamics of myosin in muscle.
2009 First International Symposium on Optical Tweezers. Zurich, Switzerland
The mechanochemistry of single myosin molecules
2009 Biophysical Society Meeting. Boston, MA
The collective mechanics of myosin in muscle.
2009 University of California Davis, Davis, CA
The collective mechanics of myosin in muscle.
2010 Alpbach Meeting on Muscle and Molecular Motors, Alpbach, Austria
Cooperative and collective behaviors in muscle
2011 University of Nevada, Reno, Physics Department Seminar
Muscle Contraction: Single Molecule to Collective Mechanics
1. Baker, J.E., I. Brust-Mascher, L.E.W. LaConte, S. Ramachandran, and D.D. Thomas. 1998. A large and distinct rotation of the myosin light chain domain upon muscle contraction. Proc. Natl. Acad. Sci. USA, 95:2944-2949.
2. Corrie, J.E.T., J.E. Baker, E.M. Ostap, D.D. Thomas, D.D., and D.R. Trentham. 1998. Transient free radicals are formed during photolysis of the 1-(2-nitrophenyl) ethyl ester of adenosine triphosphate (caged ATP). Journal of Photochemistry and Photobiology A: Chemistry, 115:49-55.
3. Brust-Mascher, I., L.E.W. LaConte, J.E. Baker, and D.D. Thomas. 1999. The myosin light-chain domain rotates upon muscle activation but not ATP hydrolysis. Biochemistry, 38:12607-12613.
4. Baker, J.E., L.E.W. LaConte, I. Brust-Mascher, and D.D. Thomas. 1999. Mechanochemical coupling in spin-labeled, active, isometric muscle. Biophys. J. 77:2657-2664.
5. Baker, J.E. and D.D. Thomas. 2000. A thermodynamic muscle model and a chemical basis for A.V. Hill’s muscle equation. J. Muscle Res. and Cell Mot. 21:335-344.
6. Baker, J.E., L.E.W. LaConte, I. Brust-Mascher, and D.D. Thomas. 2000. Mechanochemical coupling in muscle. Biophys. J. 78:2730.
7. Baker, J.E., L.E.W. LaConte, I. Brust-Mascher, and D.D. Thomas. 2000. Muscle chemistry and force. Biophys. J. 79:1687-1688.
8. Baker, J.E. and D.D. Thomas. 2000. Thermodynamics and kinetics of a molecular motor ensemble. Biophys. J. 79:1731-1736.
9. Warshaw, D.M., W.H. Guilford, Y. Freyzon, E. Krementsova, K.A. Palmiter, M.J. Tyska, J.E. Baker, and K.M. Trybus. 2000. The light chain binding domain of expressed smooth muscle heavy meromyosin acts as a mechanical lever. J. Biol. Chem. 275:37167-37172.
10. Baker, J.E., C. Brosseau, P.B. Joel, and D.M. Warshaw. 2002. The biochemical kinetics underlying actin movement generated by one and many skeletal muscle myosin molecules. Biophys. J. 82:2134-2147.
11. Baker, J.E. 2003. Muscle force emerges from dynamic actin-myosin networks, not from independent force generators. Am J Physiol Cell Physiol. 284:
12. Baker, J.E., C. Brosseau, and D.M. Warshaw. 2003. Mechanochemistry of a minus-insert smooth muscle heavy meromyosin. J. Biol. Chem. 278:28533-285539.
13. LaConte, L.E.W., J.E. Baker, D.D. Thomas. 2003. Transient kinetics and mechanics of myosin’s force generating rotation in muscle. Biochemistry 42:9797-9803.
14. Baker, J.E., E. Krementzova, G. Kennedy, A. Armstrong, K. Trybus, D.M. Warshaw 2004. Myosin V processivity: Multiple kinetic pathways for head-head coordination. Proc. Natl. Acad. Sci. USA 101:5542-6
15. Baker, J.E. 2004. Free energy transduction in a chemical motor model. J. Theor. Biol. 228:467-76.
16. Kad N.M., Kim S., Warshaw D.M., VanBuren P., Baker J.E. 2005. Single-myosin crossbridge interactions with actin filaments regulated by troponin-tropomyosin. Proc Natl Acad Sci U S A. 102:16990-5.
17. Hooft, A., Maki, E.J., Cox, K.K., Baker, J.E. 2007. An accelerated state of myosin-based actin movement. Biochemistry. 46:3513-20.
18. Resnicow, D.I., Hooft, A.M., Harrison, B.C., Baker, J.E., Leinwand, L.A. 2008. GFP failes to inhibit actin-myosin interactions in vitro. Nat. Meth. 5:212-3.
19. Jackson, D.R. and Baker, J.E. 2009. The energetics of allosteric regulation of ADP release from myosin heads. Phys. Chem. Chem. Phys. 11:4808-14.
20. Ni, S., Hong, F., Brewer, P.D., Ikebe, M., Onishi, H., Baker, J.E., Facemyer, K.C., Cremo, C.R. 2009. Kinetic and motor functions mediated by distinct regions of the regulatory light chain of smooth muscle myosin. BBA - Proteins and Proteomics. 1794:1599-605.
21. Hong, F., Haldeman, B.D., John, O.A., Brewer, P.D., Wu, Y., Ni, S., Wilson, D.P., Walsh, M.P., Baker, J.E., and Cremo, C.R. 2009. Characterization of tightly associated smooth muscle myosin-myosin light chain kinase-calmodulin complexes. J. Mol. Biol. 31:879-92.
22. Ba, M., Singer, C.A., Tyagi, M., Brophy, C., Baker, J.E., Cremo, C., Halayko, A., and Gerthoffer, W.T. 2009. HSP20 phosphorylation and airway smooth muscle relaxation. Cell Health and Cytoskeleton. 2009:27-42.
23. Sich, N.M., O’Donnell, T.J., Coulter, S.A., John, O.A., Cremo, C.R., Baker, J.E. 2010. J. Biol. Chem. 285:39150-39159.
24. Milton, D.L., Schneck, A.N., Ziech, D.A., Ba, M., Facemyer, K.C., Halayko, A.J., Baker, J.E., Gerthoffer, W.T., Cremo, C.R. 2010. Direct evidence for functional smooth muscle myosin II in the 10S self-inhibited monomeric conformation in airway smooth muscle cells. Proc Natl Acad Sci U.S.A. 108:1421-1426.
ABSTRACTS (*Platform Talk, †Session Chair)
1. Baker, J.E., O. Roopnarine, S. Ramachandran, and D.D. Thomas. 1995. Saturation transfer EPR of spin-labeled light chains in contracting muscle fibers. Biophys. J. 68:A66
2. Baker, J.E., N.J. Meyer, and D.D. Thomas. 1996. Simultaneous electron paramagnetic resonance and force of a single spin-labeled muscle fiber: correlating muscle mechanics with structural transitions in the catalytic domain of myosin. Biophys. J. 70:A266
3. Matta, J.J., J.E. Baker, J. Grinband, and D.D. Thomas. 1997. ATP-induced structural intermediates of the myosin head, detected by a spin label at Cys 707, are not modified by actin binding. Biophys. J. 72:A53
4. *Baker, J.E., I. Brust-Mascher, S. Ramachandran, and D.D. Thomas. 1997. Two distinct orientaions of spin-labeled regulatory light chains in contracting scallop muscle fibers. Biophys. J. 72:A1
5. Brust-Mascher, I., J.E. Baker, L. LaConte, S. Ramachandran, R. Lu, and D.D. Thomas. 1997. Orientations of the regulatory domain of myosin studied by site-directed spin labeling of regulatory light chains in scallop muscle fibers. Biophys. J. 72:A276
6. *Baker, J.E., I. Brust-Mascher, and D.D. Thomas. 1998. Muscle contracts with the flip of an ensemble of switches. Biophys. J. 74:A23
7. Grinband, J., J.E. Baker, D.D. Thomas. 1998. The conformational state of myosin is affected by actin in the strong binding but not in the weak binding state. Biophys. J. 74:A263
8. LaConte, L.E.W., I. Brust-Mascher, J.E. Baker, D.D. Thomas. 1998. Large rotation of the regulatory domain of myosin upon muscle contraction detected by spin label EPR. Biophys. J. 74:A363
9. Baker, J.E. and D.D. Thomas. 1999. A novel two-state chemical model of muscle contraction. Biophys. J. 76:A35
10. Baker, J.E., L.E.W LaConte, and D.D. Thomas. 1999. A direct observation of mechanochemical coupling in muscle. Biophys. J. 76:A35
11. LaConte, L.E.W., J.E. Baker, I. Brust-Mascher, and D.D. Thomas. 1999. Biochemical and mechanical modulation of two distinct orientations of the spin-labeled myosin light chain domain in muscle. Biophys. J. 76:A162
12. Baker, J.E., J. Grinband, L.E.W. LaConte, and D.D. Thomas. 2000. Thermodynamics of a motor ensemble. Biophys. J. 78:125A
13. *Baker, J.E., C. Brosseau, P.A. Joel, K. Trybus, D. Warshaw. 2001. Single molecule mechanochemistry of skeletal muscle myosin. Biophys J. 80:199A
14. Baker, J.E., P. Fagnant, and D. Warshaw. 2002. Effects of ADP on the mechanical steps of individual smooth muscle HMM molecules. Biophys. J. 82:374A
15. *†Baker, J.E., J. Gorga, D.M. Warshaw, and P. VanBuren. 2003. Evidence for thin filament regulation at the level of a single crossbridge. Biophys. J. 84:320A
16. Baker, J.E., E.B. Krementsova, G.G. Kennedy, A. Armstrong, K.M. Trybus, and D.M.. Warshaw. 2004. Myosin V Processivity: The art of motor cycle maintenance. Biophys. J.
17. Baker, J.E. 2009. The collective mechanics of myosin in muscle. Biophys. J. 96
18. Jackson, D.R. and Baker, J.E. 2008. Mechanisms For The Effects Of Viscous Solutes On Actin Sliding Velocities. Biophys. J. 94
19. Hooft, A.M., Smith, R.D., Shannon, S.F., Facemyer, K.C., Cremo, C.R., Baker, J.E. 2008. The mechanism of blebbistatin inhibition of actin-myosin mechanics. Biophys. J. 94
20. Muretta, J.M., G.W. Hennig, E. Maki, C.C. Mastick, J.E. Baker. 2007. Effects of extracellular osmotic pressure and temperature on the traffic of endosomes and endosomal transport vesicles: live cell analysis by TIRFM. Biophys. J. 92:596A.
21. Hong, F., A. Hooft, E. Maki, and J.E. Baker. 2007. An accelerated state of myosin-based actin motility.92:480A Biophys. J.
22. Kad, N.M., E.B. Krementsova, G.G. Kennedy, J.E. Baker, J.B. Patlak, K.M. Trybus, D.M. Warshaw, 2006. The talking heads of myosin V: applying load to specific biochemical transitions at the single molecule level reveals details of mechanochemical transduction. Biophys. J.
23. Jackson, D.R. and J.E. Baker. 2006. A minimal dynamic force muscle model: bridging the gap between molecular and macroscopic actin-myosin mechanochemistry. Biophys. J.
24. Cox, K.K. and J.E. Baker. 2006. The biochemistry underlying changes in muscle force. Biophys.
25. O’Donnell, T.J., Carter, M.S., Ba, M.A., Valencik, M.L., Baker, J.E., 2009. Integrin response to altered actin-myosin mechanochemistry in cardiac myocytes. Biophys. J. 96:498a
26. Facemyer, K.C., Carter, M.A., Levy, M., Schlauch, K., Herald, C.M., Baker, J.E., Cremo, C.R. 2009. Computational energetic analysis of intrafacial binding energies in interpoloated myosin states. Biophys. J. 96: 491a
27. Carter, M.S. and Baker, J.E. 2009. Simultaneous measurement of actin sliding velocities and actin-myosin dissociation kinetics. Biophys. J. 96:495a
28. Jackson, D.R., Siwinska, K., Baker, J.E. 2009 Actin-myosin binding kinetics in relation to actin sliding velocities. Biophys. J. 96:495a
29. Smith, R.D., Shannon, S.F., Stewart, T.J., John, O.N., Baker, J.E. 2009. Actin sliding velocities are influenced by the chemical driving force of actin-myosin binding. Biophys. J. 96:496a
30. Carter, M.S. and J.E. Baker. 2010. Simultaneous measurement of actin sliding velocities and actin-myosin dissociation kinetics. Biophys. J. 98:158a.
31. Ni, S., F. Hong, M.S. Carter, J.E. Baker, K.C. Facemyer, C.R. Cremo. 2010. Mutant analysis and computational analysis of the essential light chain and regulatory light chain interactions with respect to regulation of smooth muscle myosin. Biophys. J. 98:541a.
32. Jackson, D.R., T.J. Stewart, J.E. Baker. 2010. The effects of head-head interactions on myosin-based actin sliding velocities. Biophys. J. 98:145a.
33. Hong, F., B.D. Haldeman, S. Ni, N. Ruana, D.R. Jackson, J.E. Baker, C.R. Cremo. 2010. Determining the mechanism of phosphorylation of smooth muscle myosin by calmodulin-myosin light chain kinase using an in vitro model system. Biophys. J. 98:414a.
34. O’Donnell, T.J., J.E. Baker. 2010. The combined effects of ADP, ATP, and myosin density on cooperative activation of thin filaments. Biophys. J. 98:158a.
ONGOING RESEARCH SUPPORT
NIH R01 HL0909038 A Multi-Scale Study of the Interplay Between Fore Generating and Force Sensing Mechanisms. $1,354,712
NIH COBRE Smooth Muscle Plasticity – a COBRE Renewal. $750,000