Biophysics and Development Seminar: Sabine Petri, Princeton University

Title: How to make microtubules and build the mitotic spindle

The mission of my lab is to understand how cells obtain their shape, position organelles, move materials, and segregate chromosomes during cell division. Each of these functions relies on a specific architecture of the microtubule (MT) cytoskeleton. The MT cytoskeleton is generated from discrete sites and with precise timing during the cell cycle. Because the MT nucleator gamma-tubulin is abundant in the cytoplasm, its nucleation activity must be activated in space and time. Yet, the factors that control MT nucleation in the cell largely remain to be uncovered.

In this seminar, I will present our discovery of a novel MT nucleation factor that is necessary to generate the MT cytoskeleton of the cell. I will also illuminate a novel mechanism to make MTs, in which MTs originate from pre-existing MTs (branching MT nucleation), to generate MT networks that look like fireworks (see image). This mechanism is essential to assemble the mitotic spindle.