TY - JOUR
T1 - FRA1 kinesin modulates the lateral stability of cortical microtubules through cellulose synthase–Microtubule uncoupling proteins
AU - Ganguly, Anindya
AU - Zhu, Chuanmei
AU - Chen, Weizu
AU - Dixit, Ram
N1 - Funding Information:
We thank Graham Burkart for the mRuby-TUB6 microtubule marker line usedinthisstudy,KatharinaBürstenbinderforsharingunpublisheddataon FRA1–CMU interaction, and Yanbing Wang for help with pollination experiments. This work was supported by National Science Foundation (grant 1453726 to R.D.).
Publisher Copyright:
ã 2020 ASPB.
PY - 2020/8
Y1 - 2020/8
N2 - Cell wall assembly requires harmonized deposition of cellulose and matrix polysaccharides. Cortical microtubules orient the deposition of cellulose by guiding the trajectory of cellulose synthase complexes. Vesicles containing matrix polysaccharides are thought to be transported by the FRAGILE FIBER1 (FRA1) kinesin to facilitate their secretion along cortical microtubules. The cortical microtubule cytoskeleton thus may provide a platform to coordinate the delivery of cellulose and matrix polysaccharides, but the underlying molecular mechanisms remain unknown. Here, we show that the tail region of the Arabidopsis (Arabidopsis thaliana) FRA1 kinesin physically interacts with cellulose synthase–microtubule uncoupling (CMU) proteins that are important for the microtubule-dependent guidance of cellulose synthase complexes. Interaction with CMUs did not affect microtubule binding or motility of the FRA1 kinesin but differentially affected the protein levels and microtubule localization of CMU1 and CMU2, thus regulating the lateral stability of cortical microtubules. Phosphorylation of the FRA1 tail region inhibited binding to CMUs and consequently reversed the extent of cortical microtubule decoration by CMU1 and CMU2. Genetic experiments demonstrated the significance of this interaction to the growth and reproduction of Arabidopsis plants. We propose that modulation of CMU protein levels and microtubule localization by FRA1 provides a mechanism that stabilizes the sites of deposition of both cellulose and matrix polysaccharides.
AB - Cell wall assembly requires harmonized deposition of cellulose and matrix polysaccharides. Cortical microtubules orient the deposition of cellulose by guiding the trajectory of cellulose synthase complexes. Vesicles containing matrix polysaccharides are thought to be transported by the FRAGILE FIBER1 (FRA1) kinesin to facilitate their secretion along cortical microtubules. The cortical microtubule cytoskeleton thus may provide a platform to coordinate the delivery of cellulose and matrix polysaccharides, but the underlying molecular mechanisms remain unknown. Here, we show that the tail region of the Arabidopsis (Arabidopsis thaliana) FRA1 kinesin physically interacts with cellulose synthase–microtubule uncoupling (CMU) proteins that are important for the microtubule-dependent guidance of cellulose synthase complexes. Interaction with CMUs did not affect microtubule binding or motility of the FRA1 kinesin but differentially affected the protein levels and microtubule localization of CMU1 and CMU2, thus regulating the lateral stability of cortical microtubules. Phosphorylation of the FRA1 tail region inhibited binding to CMUs and consequently reversed the extent of cortical microtubule decoration by CMU1 and CMU2. Genetic experiments demonstrated the significance of this interaction to the growth and reproduction of Arabidopsis plants. We propose that modulation of CMU protein levels and microtubule localization by FRA1 provides a mechanism that stabilizes the sites of deposition of both cellulose and matrix polysaccharides.
UR - http://www.scopus.com/inward/record.url?scp=85089126544&partnerID=8YFLogxK
U2 - 10.1105/tpc.19.00700
DO - 10.1105/tpc.19.00700
M3 - Article
C2 - 32487563
AN - SCOPUS:85089126544
SN - 1040-4651
VL - 32
SP - 2508
EP - 2524
JO - Plant Cell
JF - Plant Cell
IS - 8
ER -