Gamma-tubulin coordinates nuclear envelope assembly around chromatin.

ABSTRACT: The cytosolic role of ?-tubulin as a microtubule organizer has been studied thoroughly, but its nuclear function is poorly understood. Here, we show that ?-tubulin is located throughout the chromatin of demembranated Xenopus laevis sperm and, as the nucleus is formed, ?-tubulin recruits lamin B3 and nuclear membranes. Immunodepletion of ?-tubulin impairs X. laevis assembly of both the lamina and the nuclear membrane. During nuclear formation in mammalian cell lines, ?-tubulin establishes a cellular protein boundary around chromatin that coordinates nuclear assembly of the daughter nuclei. Furthermore, expression of a ?-tubulin mutant that lacks the DNA-binding domain forms chromatin-empty nuclear like structures and demonstrate that a constant interplay between the chromatin-associated and the cytosolic pools of ?-tubulin is required and, when the balance between pools is impaired, aberrant nuclei are formed. We therefore propose that the nuclear protein meshwork formed by ?-tubulin around chromatin coordinates nuclear formation in eukaryotic cells.

SUBMITTER: Rossello CA 

PROVIDER: S-EPMC5037270 | biostudies-literature | 2016 Sep

REPOSITORIES: biostudies-literature