A Molecular Switch That Controls Filopodia Target Selection
Thursday, January 24, 2019
12:00 PM-1:30 PM
BIOMED Special Seminar
Title:
A Molecular Switch That Controls Filopodia Target Selection
Speaker:
Yuting Mao, PhD
Research Fellow
Department of Neuroscience
Thomas Jefferson University
Details:
Neural connections are initiated by motile dendritic and axonal protrusions, such as dendritic filopodia and axonal growth cones. Dendritic filopodia interview many axons and then choose the correct ones to make stable contacts. It was unclear how filopodia decipher the complex pattern of adhesive and repulsive molecular cues to find appropriate contacts.
Dr. Mao's work shows that a single cue in dendritic filopodia encodes the decision to reject or accept axonal contacts. Using super-resolution and live-cell imaging, she finds that EphB2 is located in the tips of filopodia and at nascent synaptic sites. Surprisingly, a genetically encoded indicator of EphB kinase activity, unbiased classification, and a photoactivatable EphB2 reveal that rapid activation of EphB causes filopodial retraction, whereas slow activation leads to stabilization. The stabilized filopodia contain EphB2, high EphB activity, colocalized with ephrinB1 and presynaptic marker vGLUT1.
Dr. Mao's findings support the hypothesis that EphBs determine filopodia target selection and synapse initiation. These results reveal a novel mechanism by which the cellular behavior is regulated with a simple molecular switch, greatly simplifying the process of partner selection.
Biosketch:
Yuting Mao, PhD, received her doctoral degree from Georgia State University. She is currently a research fellow in the Department of Neuroscience at Thomas Jefferson University, Philadelphia, PA. Her previous work focused on activity-dependent plasticity in sensory systems. She currently studies the roles of EphA and EphB in synaptogenesis. For many years, she has been fascinated by how nature and nurture contribute to brain development.
Contact Information
Ken Barbee
215-895-1335
barbee@drexel.edu