Cell locomotion is fundamental to development, wound healing, immune system function, and metastatic cancer. It involves a complex, dynamic interplay between proterusion, retraction, and adhesion. This proposal is focused on several major issues that we need to understand more fully in order to explain cell locomotion. The temporal and spatial distributions of traction that a cell applies to the substratum are prime determinants of cell shape and speed. Experiments are proposed to image the distribution of tractions exerted by locomoting cells and to address how traction is generated and regulated. In order to examine the combined role of contractility and adhesion in traction force generation, we will perturb both lamellar contractility and cell substratum contracts and observe the resultant effects on cell behavior. To address how adhesion and traction are regulated in functional contexts, we will apply this assay to cells that are turning and cells that are placed under """"""""load"""""""", and visualize how the traction distribution is altered in these situations. To address the molecular origin of traction force generation, we will apply this assay to cells such as Dictyostelium and its mutants where more is known about molecular motors that may generate traction. Lastly, we need to define, in rapidly locomoting cells, the molecular composition of the cell-substratum contract zones where traction is applied to the substratum. This work will employ a range of cell biological tools including immunofluorescence, transfection, and traditional and novel forms of light microscopy. The latter include release of caged physiological mediators to perturb lamellar contractility and chromophore assisted laser inactivation to locally al=ter cell adhesions. It is anticipated that the information generated in this project will ultimately lead to a deepened understanding of the role of the cell movement in normal and pathological states.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
2R01GM035325-10A1
Application #
2177853
Study Section
Cellular Biology and Physiology Subcommittee 1 (CBY)
Project Start
1985-08-30
Project End
1999-03-31
Budget Start
1995-04-01
Budget End
1996-03-31
Support Year
10
Fiscal Year
1995
Total Cost
Indirect Cost
Name
University of North Carolina Chapel Hill
Department
Anatomy/Cell Biology
Type
Schools of Medicine
DUNS #
078861598
City
Chapel Hill
State
NC
Country
United States
Zip Code
27599
Pomorski, P; Watson, J M; Haskill, S et al. (2004) How adhesion, migration, and cytoplasmic calcium transients influence interleukin-1beta mRNA stabilization in human monocytes. Cell Motil Cytoskeleton 57:143-57
Roy, Partha; Jacobson, Ken (2004) Overexpression of profilin reduces the migration of invasive breast cancer cells. Cell Motil Cytoskeleton 57:84-95
Berland, Keith; Jacobson, Ken; French, Todd et al. (2003) Electronic cameras for low-light microscopy. Methods Cell Biol 72:103-32
Rajfur, Zenon; Roy, Partha; Otey, Carol et al. (2002) Dissecting the link between stress fibres and focal adhesions by CALI with EGFP fusion proteins. Nat Cell Biol 4:286-93
Roy, Partha; Rajfur, Zenon; Pomorski, Pawel et al. (2002) Microscope-based techniques to study cell adhesion and migration. Nat Cell Biol 4:E91-6
Roy, P; Rajfur, Z; Jones, D et al. (2001) Local photorelease of caged thymosin beta4 in locomoting keratocytes causes cell turning. J Cell Biol 153:1035-48
Rotsch, C; Jacobson, K; Radmacher, M (1999) Dimensional and mechanical dynamics of active and stable edges in motile fibroblasts investigated by using atomic force microscopy. Proc Natl Acad Sci U S A 96:921-6
Oliver, T; Dembo, M; Jacobson, K (1999) Separation of propulsive and adhesive traction stresses in locomoting keratocytes. J Cell Biol 145:589-604
de Beus, E; Jacobson, K (1998) Integrin involvement in keratocyte locomotion. Cell Motil Cytoskeleton 41:126-37
Berland, K; Jacobson, K; French, T (1998) Electronic cameras for low-light microscopy. Methods Cell Biol 56:19-44

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