Cell migration is important for a wide range of physiological processes from chemotaxis and wound healing, to neuron development and embryogenesis. Cell migration requires the dynamic assembly of the actin network and remodeling of the membrane. How actin dynamics and membrane activities are coordinated during cell migration is a fundamental question in the field. The exocyst, a multiprotein complex consisting of Sec3, Sec5, Sec6, Sec8, Sec10, Sec15, Exo70 and Exo84, mediates exocytosis and polarized cell surface expansion. Recently, the exocyst emerges as an important player in cell migration. The exocyst component Exo70 directly interacts with, and kinetically stimulates, the Arp2/3 complex for actin polymerization and branching. In addition, Exo70 induces membrane curvature to generate surface protrusions. Exo70 therefore couples actin dynamics with membrane remodeling for protrusion formation and cell migration. Here we propose to examine the molecular mechanisms by which Exo70 promotes membrane curvature induction and the Arp2/3 complex-mediated actin remodeling. Furthermore, we will investigate the coordinated actions of the exocyst complex, the Arp2/3 complex, and the EHD family of pinchases in the generation of secretory vesicles from the sorting endosome that mediates integrins recycling to the leading edge for migration. We take a multi-disciplinary approach combining biochemistry, biophysics, microscopic imaging, and molecular dynamics simulation to address important emerging questions in the field. These studies will help us to elucidate the molecular mechanisms of cell migration, and contribute t our understanding of a number of diseases such neurological disorders and cancer.

Public Health Relevance

Directional cell migration is fundamental to many physiological processes such as chemotaxis, embryogenesis, and neuronal development. Studying the molecular basis of cell migration will help us understand these physiological processes and shed light on the etiologies of diseases such as neurological disorders and cancer.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
3R01GM085146-07S1
Application #
9024925
Study Section
Special Emphasis Panel (ZRG1 (02))
Program Officer
Nie, Zhongzhen
Project Start
2009-06-01
Project End
2017-04-30
Budget Start
2015-05-01
Budget End
2016-04-30
Support Year
7
Fiscal Year
2015
Total Cost
$125,000
Indirect Cost
Name
University of Pennsylvania
Department
Biology
Type
Schools of Arts and Sciences
DUNS #
042250712
City
Philadelphia
State
PA
Country
United States
Zip Code
19104
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