Kenneth A. Jacobson, Ph.D.



  • B.S., University of Wisconsin, 1964
  • M.S., University of Wisconsin, 1966
  • Ph.D., SUNY at Buffalo, 1972
  • Postdoc, Roswell Park Memorial Institute, 1972-73
  • Joined UNC in 1980

Funding Sources

  • National Institutes of Health

Research Interests

Our laboratory is interested in two basic problems in cell biology. The first concerns the fundamental microstructure of membranes, what factors determine the lateral mobility of membrane proteins and lipids, and how such mobility is related to the functions that membranes carry out. To investigate this problem we use a combination of video microscopic and molecular biology techniques. By tracking the individual movements of single lipids tagged with 30 nm gold particles, we have found that the two-dimensional Brownian motion of lipids in the plane of the membrane can be directly observed by video microscopy. This technology, as applied to membrane proteins, reveals subtle features of the lateral organization and dynamics of individual membrane proteins. For example, the current idea that microdomains, termed lipid rafts, exist in the plane of the membrane is both attractive and controversial. Attractive because such domains could have important functional significance such as being hot spots for signal transduction. Controversial because the concept is derived from biochemical extraction data and the in vivo correlate of these procedures is not known. Our current interest is to use microscopy techniques, including the laser tweezers, to determine whether rafts exist in the membranes of living cells and to determine their size and dynamics. We have found that slightly cross-linked raft resident proteins can be found in 'transient confinement zones' about 100 nm in dimension that fit the operational definition of rafts. More robust cross-linking connects the cluster to the cytoskeleton underlying the membrane at sites from which signal transduction may occur. We have also found that raft-like domains can be reconstituted in various lipid bilayer model membranes that remarkably recapitulate the properties hypothesized for lipid rafts. Papers describing or reviewing this new technology and research have been published in Science, Biochemistry, Biophys. J., Current Opinion in Cell Biology, Trends in Cell Biol. and Proc. Natl. Acad. Sci. On going current research utilizes quantum dots, fluorescence correlation microscopy and pattern recognition to study domain organization in the living cell membraneWe are now also augmenting the laser tweezers with a technique we term lateral magnetophoresis. This technique will enable differences in lateral mobility to be discerned in different regions of the surface of a single cell.

The second area of research is the problem of how cells move. This research is relevant, for example, to the aberrant cell motility exhibited in metastasis and to transendothelial cell migration involved in aspects of the inflammatory response. One major intellectual challenge is to relate global descriptions of cell movement and force production to molecular mechanisms. We have completed a kinematic description accounting for how locomoting fish scale keratocytes maintain constant shape and speed. This model accounts for not only dynamic morphological behavior but also the behavior of the cytoskeletal meshwork and cell surface receptors. And we have developed the first quantitative assay for the strength and pattern of the traction forces exerted by moving cells. Our current work involves locally perturbing cell locomotion using single cell photomanipulative techniques including chromophore assisted laser inactivation [CALI] to knock out cell adhesion molecules and laser-mediated photoactivation to quickly increase the concentration of proteins that regulate the cytoskeleton. Work has recently been published demonstrating that local photorelease of caged-thymosin beta 4, a G-actin sequestering protein, near one margin of the cell causes specific turning of that cell. Theoretical models of cell migration are now being constructed by Alex Mogilner and their validity will gauged on how well they can describe the results of these local perturbations. In the course of these investigations, we have studied the role of calcium in regulating cell contractility, adhesion and traction force development and the role of paxillin phosphorylation in the adhesion turnover that must accompany rapidly moving cells. Papers describing these studies have been published in Nature, J. Cell Biol., Cell Motility and the Cytoskeleton and Biophys. J. On going work is aimed at using fluorescent biosensors, in collaboration with Klaus Hahn, to understand the pathways by which mechanochemical signal transduction occurs to allow the cell to sense and respond to forces as well as produce them.

Selected Publications


  • Kapustina, M., Elston, T. and Jacobson, K. “Compression and dilation of the membrane-cortex layer generates rapid changes in cell shape” (2013) J. Cell Biol, 200: 95-108. A JCB Biosight podcast interview with Dr. Kapustina is available regarding this paper and the paper is a JCB Journal Club selection for free downloading.
  • Chen, Z., Lessey, E., Berginski, M.E., Cao, L., Li, J., Trepat, X., Itano, M., Gomez, S.M., Kapustina, M., Huang, C., Burridge, K., Truskey, G., and Jacobson, K. “Gleevec, an Abl family inhibitor, produces a profound change in cell shape and migration” (2013) PLoS One, 8: e52332 1-14.
  • Huang C, Rajfur Z, Yousefi N, Chen Z, Jacobson K, Ginsberg MH. Talin phosphorylation by Cdk5 regulates Smurf1-mediated talin head ubiquitylation and cell migration. Nat Cell Biol. 2009 May;11(5):624-30. Epub 2009 Apr 12.PMID: 19363486 [PubMed - in process]
  • Weinreb GE, Kapustina MT, Jacobson K, Elston TC. In silico generation of alternative hypotheses using causal mapping (CMAP). PLoS ONE. 2009;4(4):e5378. Epub 2009 Apr 29. PMID: 19401774 [PubMed - in process]
  • McLean MA, Rajfur Z, Chen Z, Humphrey D, Yang B, Sligar SG, Jacobson K. Mechanism of Chromophore Assisted Laser Inactivation Employing Fluorescent Proteins. Anal Chem. 81(5):1755-1761, 2009. [Epub ahead of print] PMID: 19199572.
  • Cai X, Lietha D, Ceccarelli DF, Karginov AV, Rajfur Z, Jacobson K, Hahn KM, Eck MJ, Schaller MD. Spatial and temporal regulation of focal adhesion kinase activity in living cells. Mol Cell Biol. 2008 Jan;28(1):201-14. Epub 2007 Oct 29. PMID: 17967873.
  • Jacobson K, Rajfur Z, Vitriol E, Hahn K. Chromophore-assisted laser inactivation in cell biology. Trends Cell Biol. 2008 Sep; 18(9):443-50.
  • Kapustina M, Weinreb GE, Costigliola N, Rajfur Z, Jacobson K, Elston TC.
  • Mechanical and biochemical modeling of cortical oscillations in spreading cells. Biophys J. 2008 Jun; 94(12):4605-20.
  • Neumann AK, Thompson NL, Jacobson K. Distribution and lateral mobility of DC-SIGN on immature dendritic cells--implications for pathogen uptake. J Cell Sci. 2008 Mar 1;121(Pt 5):634-43.
  • Cai X, Lietha D, Ceccarelli DF, Karginov AV, Rajfur Z, Jacobson K, Hahn KM, Eck MJ, Schaller MD. Spatial and temporal regulation of focal adhesion kinase activity in living cells. Mol Cell Biol. 2008 Jan; 28(1):201-14.

    • Johnson TM, Rajfur Z, Jacobson K, Beckers CJ. Immobilization of the type XIV myosin complex in Toxoplasma gondii. Mol Biol Cell. 2007 Aug; 18(8):3039-46.
  • Vitriol EA, Uetrecht AC, Shen F, Jacobson K, Bear JE. Enhanced EGFP-chromophore-assisted laser inactivation using deficient cells rescued with functional EGFP-fusion proteins. Proc Natl Acad Sci U S A. 104(16):6702-7, 2007. [See Article]


  • Loitto VM, Huang C, Sigal YJ, Jacobson K.  Filopodia are induced by aquaporin-9 expression. Exp Cell Res. 313(7):1295-306, 2007. [See Article]
  • Thelin WR, Chen Y, Gentzsch M, Kreda SM, Sallee JL, Scarlett CO, Borchers CH, Jacobson K, Stutts MJ, Milgram SL. Direct interaction with filamins modulates the stability and plasma membrane expression of CFTR.  J Clin Invest. 117(2):364-74, 2007. [See Article]



    Chen, Y., Thelin, W., Yang, B., Milgram, S. and Jacobson, K., Transient anchorage of cross-linked glycosyl-phosphatidylinositolanchored proteins depends on cholesterol, Src family kinases, caveolin, and phosphoinositides. J. Cell Biol. 175:169-78, 2006. (Highlighted in the Journal's Introduction and the cover) [See Article]


  • Weinreb G, Elston T, Jacobson K. Causal Mapping as a Tool to Mechanistically Interpret Phenomena in Cell Motility: Application to Cortical Oscillations in Spreading Cells. Cell Motil Cytoskeleton. 63(9):523-32, 2006. [See Article]
  • Prass, M., Jacobson, K., Mogilner, A. and Radmacher, M. "Direct measurement of the lamellar protrusive force in a migrating cell" J. Cell Biol., 174:767-772, 2006. [See Article]
  • Lagerholm, B.C., Weinreb, G. E., Jacobson, K., Thompson., N. L.,  Analysis Method for Measuring Submicroscopic Distances with Blinking Quantum Dots. Biophysical Journal, 91: 3050-3060, 2006. (Highlighted in Biophotonics magzine) [See Article]
  • Damljanovic V, Lagerholm BC, Jacobson K. Bulk and micropatterned conjugation of extracellular matrix proteins to characterized polyacrylamide substrates for cell mechanotransduction assays. Biotechniques. 39(6):847-51, 2005. [See Artic
  • Lagerholm BC, Weinreb GE, Jacobson K, Thompson NL. Detecting microdomains in intact cell membranes. Annu Rev Phys Chem. 56:309-36, 2005. [See Article]
  • Humphrey, D., Rajfur, Z., Vasquez, E., Scheswohl, D., Schaller, M., Jacobson, K. and Imperiali, B. "In situ photoactivation of a caged phosphotyrosine peptide derived from FAK temporarily halts lamellar extension of single migrating tumor cells", J. Biol. Chem., 280: 22091-22101 (2005).[See Article]
  • D. Humphrey, Z. Rajfur, B. Imperiali, G. Marriott, P. Roy, and K. Jacobson, "Application of light-directed activation of caged biomolecules and CALI (chromophore-assisted light inactivation) to problems in cell motility in Live Cell Imaging: A Laboratory Manual (David Spector and Bob Goldman editors)", Cold Spring Harbor Laboratory Press, pp159-176 (2005).
  • Huang, C., Jacobson, K., and Schaller, M. MAP kinases and cell migration. J. Cell Science. 117:4619-4628 (2004).
  • Huang, C., Borchers, C.H., Schaller, M. and Jacobson, K. “Phosphorylation of paxillin by p38MARK is involved in the neurite extention of PC-12 cells”, J. Cell Biol., 164:593-602, (2004).
  • P. Roy, K. Jacobson. “Overexpression of profilin reduces the migration of invasive breast cancer cells”. Cell Motility and the Cytoskeleton, 57:84-95 (2004).
  • Pomorski, P., Watson, J.M., Haskill, S. and Jacobson, K. “How Adhesion, Migration, and Cytoplasmic Calcium Transients In.uence Interleukin-1_mRNA Stabilization in Human Monocytes”, Cell Motility and the Cytoskeleton 57:143–157 (2004).
  • Huang, C., Rajfur, Z., Borchers, D., Schaller, M. and Jacobson, K. “JNK phosphorylates paxillin and regulates cell migration". Nature, 424:219 - 223 (2003).
  • Khan, T.K., Yang, B., Thompson, N.L., Maekawa, S., Epand, R.M., and Jacobson, K. “Binding of NAP-22, a Calmodulin-Binding Neuronal Protein, to Raft-like Domains in Model Membranes”. Biochemistry. 42:4780-4786 (2003).
  • Anderson, R. and Jacobson, K. “ A Role for Lipid Shells in Targeting Proteins to Caveolae, Rafts and Other Lipid Domains”, Science, 296: 1821-1825 (2002).
  • Dietrich, C., Yang, B., Fujiwara, T., Kusumi, A. and Jacobson, K. "The relationship of lipid rafts to transient confinement zones detected by single particle tracking." Biophys. J, 82: 274-284 (2002).
  • Rajfur, Z., Roy, P., Romer, L., Otey, C. and Jacobson, K. "Dissecting the link between stress fibers and focal adhesions by CALI with EGFP fusion proteins", Nature Cell Biol., 4: 286-293 (2002).
  • Dietrich, C., Bagatolli, L., Volovyk, Z., Gratton, E., Thompson,N., Levi, M., Jacobson, K., and Gratton, E. 'Lipid Rafts' Reconstituted in Model Membranes." Biophys. J., 80: 1417-1428 (2001).
  • Roy, P., Rajfur, Z., Jones, D., Marriott, G., Loew, L. and Jacobson, K. "Local photorelease of caged thyomsin beta 4 in locomoting keratocytes causes cell turning" J. Cell Biol., 153: 1035-1047 (2001).
  • Jacobson, K and Dietrich, C. "Looking at lipid rafts" Trends in Cell Biol. , 9:87-91 (1999).
  • Oliver, T., Dembo, M. and Jacobson, K. "Separation of Propulsive and Adhesive Traction Stresses in Locomoting Keratocytes", J. Cell Biol.,145: 589-604 (1999).
  • Lee, J., Ishihara, A., Oxford, G. Johnson, B. and Jacobson, K "The regulation of cell movement is mediated by stretch-activated calcium channels", Nature, 400: 382-386 (1999).