The long-term goal of this project is to define the molecular mechanisms that underlie actin assembly and understand how they contribute to cell motility. Our approach is to identify components, understand how they interact with each other in vitro using purified proteins or cell extracts, define mutations that selectively affect one interaction, and then test the biological activity of that mutant in a cell system from which the endogenous component has been depleted.
The Aims all represent the continuation of ongoing projects in the lab.
Aim 1 is to understand how cortactin contributes to actin assembly and cell motility. Cortactin is a prominent substrate for Src, the significance of which is not understood. We discovered that cortactin has a specific essential role in the osteoclast, which requires an actin-based sealing zone to resorb bone. With this system, we will examine the roles of Src phosphorylation and other biochemical functions of cortactin.
Aim 2 is to understand how capping protein, the major capper of barbed ends of actin filaments in eukaryotes, binds to actin. We will investigate the molecular basis of the interaction and use that information to understand the physiological significance of the interaction in cells. We will test a new hypothesis, the wobble model, which changes our view of the dynamic nature of a capped barbed end.
Aim 3 is to investigate the molecular basis and physiological significance of the interaction of capping protein with a number of proteins hypothesized to regulate and target capping protein in cells. The proteins include CARMIL,V1/myotrophin, twinfilin, casein kinase 2, CD2AP / Cin85, and nebulin. Relevance to public health: This research will help us understand how cells control their shape and move around the body, which are important features of development, cancer, and the response to infection. This fundamental information may be the basis for the development of new therapies for human diseases involving the molecules and processes that are discovered and illuminated.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM038542-20
Application #
7321086
Study Section
Cell Structure and Function (CSF)
Program Officer
Deatherage, James F
Project Start
1988-12-01
Project End
2009-11-30
Budget Start
2007-12-01
Budget End
2008-11-30
Support Year
20
Fiscal Year
2008
Total Cost
$543,704
Indirect Cost
Name
Washington University
Department
Anatomy/Cell Biology
Type
Schools of Medicine
DUNS #
068552207
City
Saint Louis
State
MO
Country
United States
Zip Code
63130
Kim, Joanna; Cooper, John A (2018) Septins regulate junctional integrity of endothelial monolayers. Mol Biol Cell 29:1693-1703
Yen, Matthew; Qi, Zongtai; Chen, Xuhua et al. (2018) Transposase mapping identifies the genomic targets of BAP1 in uveal melanoma. BMC Med Genomics 11:97
Santiago-Tirado, Felipe H; Onken, Michael D; Cooper, John A et al. (2017) Trojan Horse Transit Contributes to Blood-Brain Barrier Crossing of a Eukaryotic Pathogen. MBio 8:
Zhou, Julie Y; Szasz, Taylor P; Stewart-Hutchinson, Phillip J et al. (2016) L-Plastin promotes podosome longevity and supports macrophage motility. Mol Immunol 78:79-88
Wang, Xinxin; Galletta, Brian J; Cooper, John A et al. (2016) Actin-Regulator Feedback Interactions during Endocytosis. Biophys J 110:1430-43
Xu, Xiaolu; Wang, Xinxin; Todd, Elizabeth M et al. (2016) Mst1 Kinase Regulates the Actin-Bundling Protein L-Plastin To Promote T Cell Migration. J Immunol 197:1683-91
Mooren, Olivia L; Kim, Joanna; Li, Jinmei et al. (2015) Role of N-WASP in Endothelial Monolayer Formation and Integrity. J Biol Chem 290:18796-805
Mukherjee, Suranjana; Kim, Joanna; Mooren, Olivia L et al. (2015) Role of cortactin homolog HS1 in transendothelial migration of natural killer cells. PLoS One 10:e0118153
Sherman, Marc S; Lorenz, Kim; Lanier, M Hunter et al. (2015) Cell-to-cell variability in the propensity to transcribe explains correlated fluctuations in gene expression. Cell Syst 1:315-325
Onken, Michael D; Mooren, Olivia L; Mukherjee, Suranjana et al. (2014) Endothelial monolayers and transendothelial migration depend on mechanical properties of the substrate. Cytoskeleton (Hoboken) 71:695-706

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