Differentiation induces a change in microtubule organization in cell types as diverse as epithelia, muscles and neurons. This requires loss of the centrosome's microtubule organizing activity and formation of non- centrosomal microtubule arrays. We have a very limited understanding of how this reorganization occurs and the functions of the resulting microtubules. In part, this is due to lack of tools to observe and specifically perturb microtubule organization in tissues. The long-term goal of our work is to understand how diverse microtubule organizations are generated in differentiated cells and to expose their functions. The objectives of this proposal are to determine how loss of centrosomal organizing activity and microtubule minus end anchoring proteins collaborate to induce specific microtubule arrays. Based on our preliminary data, we hypothesize that differentiation causes changes in both nucleation and anchoring of microtubules at centrosomes. In combination with cytoplasmic minus end anchoring proteins, this allows for specific cytoskeletal structures to form in differentiated cells. We have developed tools/technologies that will allow us to fully characterize the changes in centrosome nucleation activity, ultrastructure and protein composition that occur upon differentiation in the epidermis. In addition, we will elucidate the underlying molecular mechanisms that lead to changes in centrosome composition and activity. Finally, we have developed novel mouse lines that will be used to examine the roles of noncentrosomal microtubule arrays in both the skin and the intestine through specific disruption of microtubule minus end anchoring proteins. These studies will elucidate the mechanisms regulating centrosome activity and microtubule reorganization in differentiated cells and determine the physiologic functions of these arrays in two different tissues.

Public Health Relevance

Our cells have internal dynamic scaffolding, composed in part of polymers called microtubules. Different organizations of microtubules accomplish such diverse feats as allowing cells to divide, migrate and to polarize. Our work will uncover how varied microtubule organizations are generated in different cell types to allow them to perform their functions. Defects in microtubule-based structures are associated with diseases as diverse as cancer, ciliopathies and neurodegenerative disorders, highlighting the importance of understanding their organization and function.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM111336-02
Application #
8891465
Study Section
Nuclear and Cytoplasmic Structure/Function and Dynamics Study Section (NCSD)
Program Officer
Gindhart, Joseph G
Project Start
2014-08-01
Project End
2018-07-31
Budget Start
2015-08-01
Budget End
2016-07-31
Support Year
2
Fiscal Year
2015
Total Cost
$297,847
Indirect Cost
$107,847
Name
Duke University
Department
Dermatology
Type
Schools of Medicine
DUNS #
044387793
City
Durham
State
NC
Country
United States
Zip Code
27705
Muroyama, Andrew; Terwilliger, Michael; Dong, Bushu et al. (2018) Genetically induced microtubule disruption in the mouse intestine impairs intracellular organization and transport. Mol Biol Cell 29:1533-1541
Sumigray, Kaelyn D; Terwilliger, Michael; Lechler, Terry (2018) Morphogenesis and Compartmentalization of the Intestinal Crypt. Dev Cell 45:183-197.e5
Muroyama, Andrew; Lechler, Terry (2017) A transgenic toolkit for visualizing and perturbing microtubules reveals unexpected functions in the epidermis. Elife 6:
Muroyama, Andrew; Lechler, Terry (2017) Microtubule organization, dynamics and functions in differentiated cells. Development 144:3012-3021
Muroyama, Andrew; Seldin, Lindsey; Lechler, Terry (2016) Divergent regulation of functionally distinct ?-tubulin complexes during differentiation. J Cell Biol 213:679-92
Seldin, Lindsey; Muroyama, Andrew; Lechler, Terry (2016) NuMA-microtubule interactions are critical for spindle orientation and the morphogenesis of diverse epidermal structures. Elife 5:
Sumigray, Kaelyn D; Lechler, Terry (2015) Cell adhesion in epidermal development and barrier formation. Curr Top Dev Biol 112:383-414
Zhou, Kang; Sumigray, Kaelyn D; Lechler, Terry (2015) The Arp2/3 complex has essential roles in vesicle trafficking and transcytosis in the mammalian small intestine. Mol Biol Cell 26:1995-2004
Morrow, Angel; Lechler, Terry (2015) Studying cell biology in the skin. Mol Biol Cell 26:4183-6