Cell migration in higher organisms is essential for multiple physiological and pathophysiological processes, including embryonic development and immune responses. Alteration of cell motility in cancer cells is one of the most dangerous features of malignant tumors, as it builds up their invasive and metastatic potential. Polarized organization of microtubule arrays is essential for polarized cell motility. However, the principles of this regulation are not yet understood. It is generally assumed that microtubules in vertebrate cells are formed by the centrosome. We have recently demonstrated that a large number of microtubules originate from the Golgi apparatus (Efimov et al, 2007). We have identified two molecular players critical for this novel phenomenon: microtubule regulatory proteins CLASPs are required for the formation of Golgi-derived microtubules, and golgin GCC185 serves as an anchor for CLASPs at the trans-Golgi network (TGN) at the Golgi periphery. In sharp contrast to symmetric microtubule arrays organized by the centrosome, microtubules nucleated at the peripheral Golgi compartment are preferentially oriented toward the leading edge in motile cells. Preliminary data suggest that the migratory potential of cells lacking Golgi-originated microtubules is compromised. Within this proposal, we will test the hypothesis that asymmetric microtubule nucleation at the Golgi is critical for motile cell polarization. We will test whether Golgi-originated microtubules exert their effect on cell polarity via regulation of the actin cytoskeleton or directional post-Golgi transport to the cell front, or both. We will also address molecular mechanisms that regulate microtubule formation at the TGN.
Our specific aims are: 1. Determine the role of Golgi-derived microtubules in the cytoskeletal polarity of motile cells. 2. Determine the role of Golgi-derived microtubules in polarized Golgi trafficking in motile cells. 3. Determine if dynamic CLASP anchoring underlies the microtubule-organizing potential of the Golgi. PUBLIC HEALTH REVELANCE: Knowledge of the molecular events that underlie cell motility is critical for understanding major health-related processes, including embryonic morphogenesis, wound healing, the immune response and cancer invasiveness. As major anticancer therapies include microtubule-specific drugs, knowledge their potential targets is especially valuable. In this proposal, we will carry out research that will determine the role of a novel Golgi-derived asymmetric microtubule array in cell motility.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM078373-05
Application #
8241079
Study Section
Cell Structure and Function (CSF)
Program Officer
Deatherage, James F
Project Start
2008-04-01
Project End
2014-03-31
Budget Start
2012-04-01
Budget End
2014-03-31
Support Year
5
Fiscal Year
2012
Total Cost
$278,092
Indirect Cost
$96,773
Name
Vanderbilt University Medical Center
Department
Anatomy/Cell Biology
Type
Schools of Medicine
DUNS #
004413456
City
Nashville
State
TN
Country
United States
Zip Code
37212
Grimaldi, Ashley D; Maki, Takahisa; Fitton, Benjamin P et al. (2014) CLASPs are required for proper microtubule localization of end-binding proteins. Dev Cell 30:343-52
Arnette, Christopher; Efimova, Nadia; Zhu, Xiaodong et al. (2014) Microtubule segment stabilization by RASSF1A is required for proper microtubule dynamics and Golgi integrity. Mol Biol Cell 25:800-10
Alieva, Irina B; Zemskov, Evgeny A; Smurova, Ksenija M et al. (2013) The leading role of microtubules in endothelial barrier dysfunction: disassembly of peripheral microtubules leaves behind the cytoskeletal reorganization. J Cell Biochem 114:2258-72
Zhu, Xiaodong; Kaverina, Irina (2013) Golgi as an MTOC: making microtubules for its own good. Histochem Cell Biol 140:361-7
Maia, Ana Rita Ramada; Zhu, Xiaodong; Miller, Paul et al. (2013) Modulation of Golgi-associated microtubule nucleation throughout the cell cycle. Cytoskeleton (Hoboken) 70:32-43
Vinogradova, Tatiana; Paul, Raja; Grimaldi, Ashley D et al. (2012) Concerted effort of centrosomal and Golgi-derived microtubules is required for proper Golgi complex assembly but not for maintenance. Mol Biol Cell 23:820-33
Kaverina, Irina; Straube, Anne (2011) Regulation of cell migration by dynamic microtubules. Semin Cell Dev Biol 22:968-74
Zhu, Xiaodong; Kaverina, Irina (2011) Quantification of asymmetric microtubule nucleation at subcellular structures. Methods Mol Biol 777:235-44
Zhu, Xiaodong; Wang, Junxia; Moriguchi, Kazuki et al. (2011) Proper regulation of Cdc42 activity is required for tight actin concentration at the equator during cytokinesis in adherent mammalian cells. Exp Cell Res 317:2384-9
Sung, Bong Hwan; Zhu, Xiaodong; Kaverina, Irina et al. (2011) Cortactin controls cell motility and lamellipodial dynamics by regulating ECM secretion. Curr Biol 21:1460-9

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