EXCEED THE SPACE PROVIDED. We have developed a powerful new Fluorescent Speckle Microscopy (FSM) method that utilizes epi-fluorescence microscopy to analyze the movement, assembly, and disassembly of macromolecular structures in vivo and in vitro. Initially, we devised this method for studying the dynamics of the cytoskeletal polymers, microtubules and actin filaments in cell locomotion and division. In FSM, structures are assembled from a low fraction of fluorescently labeled subunits together with unlabeled subunits and imaged with high-resolution optics and a sensitive, low-noise digital camera. FSM is achieved in living cells by microinjection or expression of a low amount of fluorophore-conjugated subunits. Stochastic variations in the number of fluorescent subunits per resolution-limited image region results in a 'speckled' appearance of the assembled structure. In time-lapse FSM, movement and changes in speckle intensity act as reporters for structure translocation, assembly and disassembly. FSM is fast becoming the method of choice for studies of cytoskeleton dynamics. However, FSM requires further development to reach its full potential for biomedical research. Focus drifts during imaging are a major source of FSM artifact, and the versatility of FSM for various fluorescence microscope modes has to be demonstrated. In addition, the analysis of time-lapse FSM images are currently done by hand, which is slow, incomplete, and prone to error. This must be replaced by automated, quantitative FSM image analysis. Finally, FSM image generation and analysis techniques have to be broadened to general biomacromolecular assemblies. To achieve these goals, we have the following Specific Aims: 1. Hardware Development: To develop focus-stabilized FSM and multi-spectral Total Internal Reflection FSM (TIR-FSM) for studying protein dynamics in vitro and on ventral cell surfaces in vivo. 2. Software Development: To develop software for automatic quantitative analysis of protein dynamics in time-lapse FSM images. 3. Applications: To use multi-spectral FSM, TIR-FSM, and analysis software for studying other biologically important systems besides cytoskeletal polymers. These advances will allow FSM to become a powerful tool for studying molecular dynamics in cell biology, neurobiology, biotechnology, and m_f_ri_lq q_i_n_ PERFORMANCE SITE ========================================Section End===========================================

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM067230-03
Application #
6839430
Study Section
Special Emphasis Panel (ZRG1-SSS-U (01))
Program Officer
Deatherage, James F
Project Start
2003-01-01
Project End
2006-12-31
Budget Start
2005-01-01
Budget End
2005-12-31
Support Year
3
Fiscal Year
2005
Total Cost
$396,206
Indirect Cost
Name
Scripps Research Institute
Department
Type
DUNS #
781613492
City
La Jolla
State
CA
Country
United States
Zip Code
92037
Roudot, Philippe; Liya Ding; Jaqaman, Khuloud et al. (2017) Piecewise-Stationary Motion Modeling and Iterative Smoothing to Track Heterogeneous Particle Motions in Dense Environments. IEEE Trans Image Process 26:5395-5410
Kwon, Mijung; Bagonis, Maria; Danuser, Gaudenz et al. (2015) Direct Microtubule-Binding by Myosin-10 Orients Centrosomes toward Retraction Fibers and Subcortical Actin Clouds. Dev Cell 34:323-37
Loerke, Dinah; le Duc, Quint; Blonk, Iris et al. (2012) Quantitative imaging of epithelial cell scattering identifies specific inhibitors of cell motility and cell-cell dissociation. Sci Signal 5:rs5
Schaefer, Andrew W; Schoonderwoert, Vincent Th G; Ji, Lin et al. (2008) Coordination of actin filament and microtubule dynamics during neurite outgrowth. Dev Cell 15:146-62
Lim, Yangmi; Lim, Ssang-Taek; Tomar, Alok et al. (2008) PyK2 and FAK connections to p190Rho guanine nucleotide exchange factor regulate RhoA activity, focal adhesion formation, and cell motility. J Cell Biol 180:187-203
Delorme, Violaine; Machacek, Matthias; DerMardirossian, Celine et al. (2007) Cofilin activity downstream of Pak1 regulates cell protrusion efficiency by organizing lamellipodium and lamella actin networks. Dev Cell 13:646-62
Gupton, Stephanie L; Eisenmann, Kathryn; Alberts, Arthur S et al. (2007) mDia2 regulates actin and focal adhesion dynamics and organization in the lamella for efficient epithelial cell migration. J Cell Sci 120:3475-87
Yam, Patricia T; Wilson, Cyrus A; Ji, Lin et al. (2007) Actin-myosin network reorganization breaks symmetry at the cell rear to spontaneously initiate polarized cell motility. J Cell Biol 178:1207-21
Burnette, Dylan T; Schaefer, Andrew W; Ji, Lin et al. (2007) Filopodial actin bundles are not necessary for microtubule advance into the peripheral domain of Aplysia neuronal growth cones. Nat Cell Biol 9:1360-9
Yarar, Defne; Waterman-Storer, Clare M; Schmid, Sandra L (2007) SNX9 couples actin assembly to phosphoinositide signals and is required for membrane remodeling during endocytosis. Dev Cell 13:43-56

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