News Finding: "The work by Petry and co-workers now shows that XMAP215, previously considered a microtubule 'polymerase' involved in microtubule elongation, acts synergistically with g-tubulin to promote efficient microtubule nucleation.
Paper Finding: In this study, we demonstrate that XMAP215 is a bona fide MT nucleation factor that cooperates with γ -TuRC.
News Context: That search may now be over. "The work by Petry and co-workers now shows that XMAP215, previously considered a microtubule 'polymerase' involved in microtubule elongation, acts synergistically with g-tubulin to promote efficient microtubule nucleation. The work provides an answer to this critical puzzle in our understanding of microtubule regulation in the cell."
Paper Context: Furthermore, if XMAP215 were to function as a MT nucleator, its relationship with the universal nucleator γ -TuRC needs to be established and their mechanism determined 27,34,35 . In this study, we demonstrate that XMAP215 is a bona fide MT nucleation factor that cooperates with γ -TuRC. Using Xenopus egg extracts to resolve individual nucleation events, we show that XMAP215 determines the extent of MT nucleation in the cytoplasm.