SMBP Group Meeting: Michael O'Brien (Harvard)

Tuesday Apr 1, 2025, 2:00 PM → 3:00 PM America/New_York

3rd Floor Classroom (162 Fifth Avenue)

Speaker: Michael O'Brien

Topic: Mapping out the Microtubule Lattice in situ with Cryo-EM: Towards A Statistical Physics of Motor-Mediated Microtubule Interactions

Abstract: Collective behavior of microtubules and molecular motors underlies much of sub-cellular self-organization, including the formation of the meiotic and mitotic spindles. While large-scale emergent properties of microtubule networks can be well-described using continuum theories, how these properties arise from the behaviors of motor mediated microtubule-microtubule interactions remains poorly understood, primarily due to experimental limitations in characterizing these systems at the relevant length scales. Fortunately, recent advances in cryoelectron microscopy (cryo-EM) make it possible to resolve high-resolution behaviors in dynamical steady states of microtubules and molecular motors in-situ. My work seeks to measure the positions and conformations of motors and microtubule lattice sites in these dynamic steady states, ultimately to inform statistical mechanical models for the collective behaviors of motors, such as traffic jams and, ultimately, motor mediated microtubule-microtubule interactions. In this talk, I will discuss my work developing a novel computational framework for analyzing microtubules, which leverages autograd-enabled bayesian probabilistic modeling and a new cryo-EM image simulation library called cryoJAX. Ultimately, these tools will allow us to understand the heterogeneity along the microtubule lattice, for example in snapshots of motors walking on microtubules.