RT Journal Article
SR Electronic
T1 CLASP promotes microtubule array reorientation by acting as a specific severing rescue factor
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 196329
DO 10.1101/196329
A1 Jelmer J. Lindeboom
A1 Masayoshi Nakamura
A1 Marco Saltini
A1 Anneke Hibbel
A1 Ankit Walia
A1 Tijs Ketelaar
A1 Anne Mie C. Emons
A1 John C. Sedbrook
A1 Viktor Kirik
A1 Bela M. Mulder
A1 David W. Ehrhardt
YR 2018
UL http://biorxiv.org/content/early/2018/03/07/196329.abstract
AB Eukaryotic cells build microtubule arrays to perform essential cellular functions, including division and morphogenesis. Central to building and reorganizing these cytoskeletal arrays is the creation of new polymers. While nucleation has been the major focus of study for new microtubule generation, severing has been proposed as an alternative mechanism to create new polymers, a possibility recently shown to drive the reorientation of cortical arrays of higher plants in response to blue light perception. An important and unanswered question is how the new plus ends created by severing are stabilized to promote net microtubule generation. Here we identify the conserved protein CLASP as a potent in vivo stabilizer of new plus ends generated by katanin mediated severing in the model plant Arabidopsis. In clasp mutants, the fraction of plus ends rescued after severing was reduced by approximately 4.3 - fold and cortical arrays were defective in their ability to reorient. Using the in vivo measurements of molecular behavior, our computational modeling identifies the specific rescue activity of CLASP at severed ends as the key function of CLASP that allows severing to generate a new microtubule array.