 |
| |  |
| | | |
| FACULTY BIOGRAPHY |
|
| <-- Back
|
| Michael Sheetz |
| William R Kenan Jr. Professor |
|
|
| Lab Website
Force-dependent Signaling
The morphology of cells, organs and whole organisms is determined by the generation of forces on the immediate environment, which is either extracellular matrix or adjacent cells. Thus, control of forces controls morphology. Further, a hallmark of cancer is cell transformation, which is defined as a cell’s ability to grow on soft agar, i.e., in the absence force. There are many pathways of force transduction in cells and we have identified two in recent studies, one involving force generation at fibronectin bead binding sites (Galbraith et al., 2002) by a protein tyrosine phosphatase-integrin complex (von Wichert et al., 2003). The second involving the direct alteration of cytoskeleton morphology by force (Sawada and Sheetz, 2002). The protein tyrosine phosphatase is at the leading edge of the cell and is involved in early, low force, activation. Immediately downstream are the Src family kinases (oncogenes) that also affect motility. In the case of the second pathway, our working model is that the cytoskeleton is unfolding with force and thereby binding and activating signaling enzymes. We are currently engaged in studies to understand the detailed molecular mechanisms involved and the extent of the involvement of these two pathways in a variety of phenomena from fertilization to brain function. Further, we are developing several new tools and protocols for measuring cell forces at the molecular level (Jiang et al., 2003), which are revealing many new aspects of how cells can both generate and respond to external forces. An overview of some of the proteins involved and their specific roles in force-dependent signaling and motility is provided at Bead Force Transduction.
Cell Spreading and Force Generation
We have an effort underway to define quantitatively the steps involved in cell adhesion to and spreading on a matrix-coated surface. Using a variety of mouse fibroblast cell lines that are missing proteins in various motility pathways, we are determining the quantitative changes in the spreading process. This will enable us to generate a working model of the process of spreading that is consistent with previous studies as well as our findings. The working model can be accessed at Cell Spreading.
Membrane (Lipid)-Cytoskeleton Adhesion and PIP2
Cell plasma membranes conform to the cytoskeleton shape through an extensive interaction between them. After many studies of the strength of membrane-cytoskeleton adhesion, there appears to be a very tight control of the adhesion energy through the regulation of the free concentration of phosphatidylinositol 4,5 diphosphate (PIP2)(reviewed in Sheetz, 2001) (Raucher et al., 2000). Now we are exploring how the free level of PIP2 is regulated and which cytoskeleton proteins interact with PIP2 in vivo. Much of our effort is focusing on the lipid binding proteins that are in the MARCKS class of proteins. Lipid control of membrane-cytoskeleton adhesion has important implications for membrane structure and the control of a wide variety of cell functions.
Organelle Traffic in Neurons
We have a long-standing interest in the molecular basis of organelle transport in neurons. Recent studies are focused on the control of mitochondrial movements since they are critical organelles that move in two directions on microtubules and interact with myosin. Thus, they are ideal for studying control of motor switching and regulation of motility. Using in vivo and in vitro assays of directional movement of mitochondria on microtubules, we have found a critical role for inositol lipids in the cytoplasmic dynein but not kinesin-dependent movements (De Vos et al., 2003). Now we will analyze whether the basis of control is through vesicle binding or motor activation. Additional projects are focussed on membrane binding sites for kinesin such as kinectin and the role of tension in ER and Golgi networks.
Bacterial Pilus Retraction
The retraction of bacterial pili appears to constitute a robust motility mechanism (Merz et al., 2000) that can generate the largest force of any known single molecular motor (Maier et al., 2002). There are many mutations in the pilus retraction pathway and we are now collaborating with groups who have characterized these mutations to understand the mechanism of retraction and the role of force generation in pathogenesis.
MedLine Listing of Dr. Sheetz's Publications |
|
|
|
Representative Recent Publications
|
|
- von Wichert G, Krndija D, Schmid H, von Wichert G, Haerter G, Adler G, Seufferlein T, Sheetz MP. (2008) Focal adhesion kinase mediates defects in the force-dependent reinforcement of initial integrin-cytoskeleton linkages in metastatic colon cancer cell lines. Eur J Cell Biol 87(1): 1-16.
- Perez TD, Tamada M, Sheetz MP, Nelson WJ (2008) Immediate-early signaling induced by E-cadherin engagement and adhesion J Biol Chem 283(8): 5014-22.
- Zhang X, Jiang G, Cai Y, Monkley SJ, Critchley DR, Sheetz MP. (2008) Talin depletion reveals independence of initial cell spreading from integrin activation and traction. Nat Cell Biol
- Kostic A, Sap J, Sheetz MP. (2007) RPTPalpha is required for rigidity-dependent inhibition of extension and differentiation of hippocampal neurons J Cell Sci 120(Pt 21): 3895-904.
- Sims TN, Soos TJ, Xenias HS, Dubin-Thaler B, Hofman JM, Waite JC, Cameron TO, Thomas VK, Varma R, Wiggins CH, Sheetz MP, Littman DR, Dustin ML (2007) Opposing effects of PKCtheta and WASp on symmetry breaking and relocation of the immunological synapse. Cell 129(4): 773-85.
- Boldogh IR, Pon LA, Sheetz MP, De Vos KJ. (2007) Cell-free assays for mitochondria-cytoskeleton interactions Methods Cell Biol 80: 683-706.
- Calloway NT, Choob M, Sanz A, Sheetz MP, Miller LW, Cornish VW (2007) Optimized fluorescent trimethoprim derivatives for in vivo protein labeling. Chembiochem 7;8(7): 767-74.
- De Vos KJ, Sheetz MP (2007) Visualization and quantification of mitochondrial dynamics in living animal cells. Methods Cell Biol 80: 627-82.
- Tran AD, Marmo TP, Salam AA, Che S, Finkelstein E, Kabarriti R, Xenias HS, Mazitschek R, Hubbert C, Kawaguchi Y, Sheetz MP, Yao TP, Bulinski JC. (2007) HDAC6 deacetylation of tubulin modulates dynamics of cellular adhesions. J Cell Sci J Cell Sci 120( 8): 1469-79..
- Ahmed I, Ponery AS, Nur-E-Kamal A, Kamal J, Meshel AS, Sheetz MP, Schindler M, Meiners S. (2007) Morphology, cytoskeletal organization, and myosin dynamics of mouse embryonic fibroblasts cultured on nanofibrillar surfaces. Mol Cell Biochem 301(1-2): 241-9.
- Giannone G, Dubin-Thaler BJ, Rossier O, Cai Y, Chaga O, Jiang G, Beaver W, Döbereiner HG, Freund Y, Borisy G, Sheetz MP. (2007) Lamellipodial actin mechanically links myosin activity with adhesion-site formation. Cell 128(3): 561-75.
- Tamada M, Perez TD, Nelson WJ, Sheetz MP. (2007) Two distinct modes of myosin assembly and dynamics during epithelial wound closure J Cell Biol 176(1): 27-33.
- Sawada Y, Tamada M, Dubin-Thaler BJ, Cherniavskaya O, Sakai R, Tanaka S, Sheetz MP (2006) Force sensing by mechanical extension of the Src family kinase substrate p130Cas. Cell 127(5): 1015-26.
- Cai Y, Biais N, Giannone G, Tanase M, Jiang G, Hofman JM, Wiggins CH, Silberzan P, Buguin A, Ladoux B, Sheetz MP. (2006) Nonmuscle myosin IIA-dependent force inhibits cell spreading and drives F-actin flow. Biophys J 91(10): 3907-20.
- Döbereiner HG, Dubin-Thaler BJ, Hofman JM, Xenias HS, Sims TN, Giannone G, Dustin ML, Wiggins CH, Sheetz MP (2006) ustin ML, Wiggins CH, Sheetz MP. Lateral membrane waves constitute a universal dynamic pattern of motile cells. Phys Rev Lett 97(3): 038102.
- Sheetz MP, Sable JE, Döbereiner HG. (2006) Continuous membrane-cytoskeleton adhesion requires continuous accommodation to lipid and cytoskeleton dynamics. Annu Rev Biophys Biomol Struct 35: 417-34.
- Miller KE, Sheetz MP (2006) Direct evidence for coherent low velocity axonal transport of mitochondria. J Cell Biol 173(3): 373-81.
- Kostic A, Sheetz MP (2006) Fibronectin rigidity response through Fyn and p130Cas recruitment to the leading edge. Mol Biol Cell 17(6): 2684-95.
- Ada-Nguema AS, Xenias H, Hofman JM, Wiggins CH, Sheetz MP, Keely PJ (2006) The small GTPase R-Ras regulates organization of actin and drives membrane protrusions through the activity of PLCepsilon. J Cell Sci 119(Pt 7): 1307-19.
- Giannone G, Sheetz MP (2006) Substrate rigidity and force define form through tyrosine phosphatase and kinase pathways Trends Cell Biol 16(4): 213-23.
- Jiang G, Huang AH, Cai Y, Tanase M, Sheetz MP (2006) Rigidity sensing at the leading edge through alphavbeta3 integrins and RPTPalpha. Biophys J 90(5): 1804-9.
- von Wichert G, Sheetz MP. (2005) Mechanisms of disease: the biophysical interpretation of the ECM affects physiological and pathophysiological cellular behavior. Z Gastroenterol 43(12): 1329-36.
- De Vos KJ, Allan VJ, Grierson AJ, Sheetz MP (2005) Mitochondrial function and actin regulate dynamin-related protein 1-dependent mitochondrial fission. Curr Biol 15(7): 678-83.
- Miller LW, Cai Y, Sheetz MP, Cornish VW. (2005) In vivo protein labeling with trimethoprim conjugates: a flexible chemical tag. Nat Methods 2(4): 255-7.
- Döbereiner HG, Dubin-Thaler BJ, Giannone G, Sheetz MP. (2005) Force sensing and generation in cell phases: analyses of complex functions. J Appl Physiol 98(4): 1542-6.
- Meshel AS, Wei Q, Adelstein RS, Sheetz MP. (2005) Basic mechanism of three-dimensional collagen fibre transport by fibroblasts. Nat Cell Biol 7(2): 157-64.
- Tamada M, Sheetz MP, Sawada Y. (2004) Activation of a signaling cascade by cytoskeleton stretch Dev Cell 2004: 709-18.
- Döbereiner HG, Dubin-Thaler B, Giannone G, Xenias HS, Sheetz MP. (2004) Dynamic phase transitions in cell spreading. Phys Rev Lett 93(10): 108105.
- Maier B, Koomey M, Sheetz MP (2004) A force-dependent switch reverses type IV pilus retraction. Proc Natl Acad Sci 101(30): 10961-6.
- De Vos, K., J. Sable, K.E. Miller, and M.P. Sheetz (2003) Expression of phosphatidylinositol (4.5) bisphosphate-specific pleckstrin homology domains alters direction but not level of axonal transport of mitochondria Mol Biol Cell In Press.
- Jiang, G., G. Giannone, D.R. Critchley, E. Fukumoto, and M.P. Sheetz (2003) Two-piconewton slip bond between fibronectin and the cytoskeleton depends on talin Nature 424: 334-7. Article
- Galbraith, C.G., K.M. Yamada, and M.P. Sheetz (2002) The relationship between force and focal complex development J Cell Biol 159: 695-705. Article
- Maier, B., L. Potter, M. So, C.D. Long, H.S. Seifert, and M.P. Sheetz (2002) Single pilus motor forces exceed 100 pN Proc Natl Acad Sci U S A 99: 16012-7. Article
- Sawada, Y., and M.P. Sheetz (2002) Force transduction by Triton cytoskeletons J Cell Biol 156: 609-15. Article
- Sheetz, M.P. (2001) Cell control by membrane-cytoskeleton adhesion Nat. Rev. Molec. Cell Biol. 2: 392-396. Article
- Merz, A. J., M. So, and M.P. Sheetz. (2000) Pilus retraction powers bacterial twitching motility Nature 407: 98-102. Article
- Miller, K. E. and M.P. Sheetz (2000) Characterization of myosin V binding to brain vesicles J. Biol. Chem. 275: 2598-2606.
- Raucher, D., and M. P. Sheetz. (2000) Cell spreading is regulated by membrane tension J. Cell Biol. 148: 127-136. Article
- Raucher, D., T. Stauffer, W. Chen, K. Shen, S. Guo, J.D. York, M.P. Sheetz, and T. Meyer (2000) Phosphatidylinositol 4,5-bisphosphate functions as a second messenger that regulates cytoskeleton-plasma membrane adhesion Cell 100: 221-228. Article
- Felsenfeld, D.P., Schwartzberg, P. L., Venegas, A., Tse, R. and Sheetz, M.P. (1999) Selective regulation of integrin-cytoskeleton interactions by the tyrosine kinase Src Nature Cell Biol. 1: 200-206.
- Galbraith, C. G. and M.P. Sheetz (1999) Keratocytes pull with similar forces on their dorsal and ventral surfaces J. Cell Biol. 147: 1313-1323.
- Raucher, D., and Sheetz, M. P. (1999) Membrane expansion increases endocytosis rate during mitosis J. Cell Biol. 144: 497-506.
- Choquet, D., D.P. Felsenfeld, and M.P. Sheetz. (1997) Extracellular Matrix Rigidity Causes Strengthening of Integrin-Cytoskeletal Linkages Cell 88: 39-48.
|
|
| | |
|
|
