Department of Medicine

Rheumatology and Clinical Immunology Faculty

Michael R. Bubb, M.D.
Associate Professor of Medicine
Basic science faculty
Fellowship: NIH Bethesda MD
Residency: Barnes Hospital, Washington Univ., St. Louis, MO
MD: Johns Hopkins (1985)
BS Engineering Physics: South Dakota State University (1981)

Editorial boards:

FEBS Letters

Area(s) of interest:

cytoskeletal proteins, rheumatoid arthritis & autoimmunity, cancer biology, neurodevelopment, marine natural products

Advisory panels and committees:

Chairperson, Research & Development Committee, Malcom Randall VAMC, Gainesville, FL; University of Florida College of Medicine Medical Selection Committee; NIH special emphasis panel review: protein structure and function in aging and late life disease; Department of Defense Breast Cancer Research Section panel member (CET1); NSF Div. Molecular Cellular Biosciences (BIO/MCB), ad hoc reviewer; member, Faculty of 1000 for Cell Biology/Cytoskeleton

Research Interests:

Dr. Bubb's laboratory studies the regulation of actin polymerization in cell motility. We investigate the cell biology and biochemistry of actin-binding proteins specifically as they pertain to such topics as apoptosis, angiogenesis, immunology and cancer biology. We also study pharmacologic agents that affect actin polymerization. We use a variety of biophysical techniques to answer specific questions regarding mechanisms controlling cell motility, including time-dependent fluorescence spectroscopy and analytical ultracentrifugation.

Specific ongoing projects include (1) a study of the MARCKS protein as it relates to neurodevelopment, synaptic plasticity & memory, (2) a study of the structure & immunomodulatory properties of thymosin 4, and (3) the development of cancer chemotherapeutic agents that target the actin cytoskeleton, and (4) a study of predicted outcomes and response to therapy in rheumatoid arthritis based on the role of TNF-alpha in cytoskeletal dynamics.

Contact information:

The figure shows the backbone trace of a dimer of antiparallel actin dimers representing the crystal structure of actin in complex with latrunculin A and polylysine. The inset diagram illustrates a hypothesis based on this structure that may explain the mechanism by which antiparallel actin dimers are paradoxically assembled into an actin filament with exclusively parallel subunits. The findings are described in: Bubb et al., J. Biol. Chem. 277 (2002) 20999-21006.

Professional experience:

A complete list of Dr. Bubb’s publications on PubMed

Representative, recent publications:

• Bubb, M.R., Spector, I., Beyer, B.B., & Fosen, K.M. Effects of jasplakinolide on the kinetics of actin polymerization: an explanation for certain in vivo observations. J. Biol. Chem. 275 (2000) 5163-5170.
• Yarmola, E.G., Somasundaram, T., Boring, T.A., Spector, I., & Bubb, M.R. Actin latrunculin A structure and function: differential modulation of actin binding protein function by latrunculin A. J. Biol. Chem. 275 (2000) 28120-28127.
• Zharikov, S.I., Sigova, A.A., Chen, S., Bubb, M.R., & Block, E.R. Cytoskeletal regulation of the L-arginine:NO pathway in pulmonary artery endothelial cells. Am J. Physiol. 280 (2001) L465-L473.
• Yarmola E.G., Parikh, S. & Bubb, M.R. Formation and implications of ternary complex of profilin, thymosin β4, and actin. J. Biol. Chem. 276 (2001) 45555-63.
• Yarmola, E.G., Edison, A.S., Lenox, R.H., & Bubb, M.R. Actin filament cross-linking by MARCKS: characterization of two actin binding sites within the phosphorylation site domain. J. Biol. Chem. 276 (2001) 22351-22358.
• McGarry, M.A., Charles, G.D., Medrano, T., Bubb, M.R., Campbell-Thompson, M., & Shiverick, K.T. Benzo(a)pyrene, but not dioxin, alters human endometrial RL95-2 cell attachment and adhesion. BBRC 294 (2002) 101-107.
• Bubb, M.R., Govindasamy, L., Yarmola, E.G., Vorobiev, S.M., Almo, S.C., Somasundaram, T., Chapman, M., Agbandje-McKenna, M., & McKenna, R. Polylysine induces an antiparallel actin dimer that nucleates filament assembly: crystal structure at 3.5-Å resolution J. Biol. Chem. 277 (2002) 20999-21006.
• Hertzog, M., Yarmola, E.G., Didry, D., Bubb, M.R., & Carlier, M.F. Control of actin dynamics by proteins made of β-thymosin repeats: The Actobindin Family. J. Biol. Chem. 277 (2002) 14786-14792.
• Su, Y., Edwards-Bennett, S., Bubb, M.R., & Block E.R. Regulation of endothelial nitric oxide synthase by the actin cytoskeleton. Am. J. Physiol. 284 (2003) C1542-1549.
• Bubb, M.R., Yarmola, E.G., & Southwick F.S. Depolymerization of actin filaments by profilin: effects of profilin on capping protein function. J. Biol. Chem. 278 (2003) 24629-24635.
• Bubb, M.R. “Thymosin 4 interactions” Litwack, G. (Ed.): Vitam. Horm. 66, 297-316, 2003 (Academic Press, San Diego CA).
• Chen, S.H., Bubb, M.R., Yarmola, E.G., Zuo, J., Jiang, J., Lee, B.S., Lu, M., Gluck, S.L., Hurst, I.R., & Holliday. L.S. Vacuolar H+-ATPase binding to microfilaments: regulation in response to phosphatidylinositol 3-kinase activity and detailed characterization of the actin binding site in subunit B. J. Biol. Chem. 279 (2004) 7988-98.
• Reutzel, R., Yoshioka, C., Govindasamy, L., Yarmola, E.G., Agbandje-McKenna, M., Bubb, M.R., & McKenna, R. Actin crystal dynamics: structural implications for F-actin nucleation, polymerization, and branching mediated by the anti-parallel dimer. J. Structural Biol. 146 (2004) 291-301.
• Yarmola, E.G. & Bubb, M.R. Effects of profilin and thymosin beta 4 on the critical concentration of actin demonstrated in vitro and in cell extracts with a novel direct assay. J. Biol. Chem. 2004 Jun 7 [Epub ahead of print].

For information about this page, please contact Michael Bubb, M.D.