Influence of the centrosome on the structure of nucleated microtubules

Abstract

The capacity of the centrosome to influence the lattice structure of nucleated microtubules was studied in vitro. Brain microtubules self-assembled to give predominantly (98%) 14-protofilament microtubules. However, under exactly the same conditions of assembly they grew off of purified centrosomes from neuroblastoma cells to give mostly (82%) 13-protofilament microtubules. Thus, the nucleation sites on the centrosome constrained the microtubule lattice to yield the number of protofilaments usually found in vivo.