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Biology

Biology Faculty Publications & Presentations

Microtubule-Associated Proteins

Publication Year

Articles 1 - 3 of 3

Full-Text Articles in Biochemistry

Microtubule Severing At Crossover Sites By Katanin Generates Ordered Cortical Microtubule Arrays In Arabidopsis, Quan Zhang, Erica Fishel, Tyler Bertroche, Ram Dixit Nov 2013

Microtubule Severing At Crossover Sites By Katanin Generates Ordered Cortical Microtubule Arrays In Arabidopsis, Quan Zhang, Erica Fishel, Tyler Bertroche, Ram Dixit

Biology Faculty Publications & Presentations

Highlights

  • Severing primarily depolymerizes the overlying CMT at crossover sites
  • Severing probability increases nonlinearly with crossover time
  • Katanin localizes to crossover sites and is required for severing
  • Loss of katanin activity prevents the formation of coaligned CMT arrays

Summary
The noncentrosomal cortical microtubules (CMTs) of land plants form highly ordered parallel arrays that mediate cell morphogenesis by orienting cellulose deposition [1, 2 and 3]. Since new CMTs initiate from dispersed cortical sites at random orientations [4], parallel array organization is hypothesized to require selective pruning of CMTs that are not in the dominant orientation. Severing of CMTs at crossover sites …


Single Molecule Analysis Of The Arabidopsis Fra1 Kinesin Shows That It Is A Functional Motor Protein With Unusually High Processivity, Chuanmei Zhu, Ram Dixit Sep 2011

Single Molecule Analysis Of The Arabidopsis Fra1 Kinesin Shows That It Is A Functional Motor Protein With Unusually High Processivity, Chuanmei Zhu, Ram Dixit

Biology Faculty Publications & Presentations

The Arabidopsis FRA1 kinesin contributes to the organization of cellulose microfibrils through an unknown mechanism. The cortical localization of this kinesin during interphase raises the possibility that it transports cell wall-related cargoes along cortical microtubules that either directly or indirectly influence cellulose microfibril patterning. To determine whether FRA1 is an authentic motor protein, we combined bulk biochemical assays and single molecule fluorescence imaging to analyze the motor properties of recombinant, GFP-tagged FRA1 containing the motor and coiled-coil domains (designated as FRA1(707)–GFP). We found that FRA1(707)–GFP binds to microtubules in an ATP-dependent manner and that its ATPase activity is dramatically stimulated …


Sunday Driver/Jip3 Binds Kinesin Heavy Chain Directly And Enhances Its Motility, Faneng Sun, Chuanmei Zhu, Ram Dixit, Valeria Cavalli Jul 2011

Sunday Driver/Jip3 Binds Kinesin Heavy Chain Directly And Enhances Its Motility, Faneng Sun, Chuanmei Zhu, Ram Dixit, Valeria Cavalli

Biology Faculty Publications & Presentations

Neuronal development, function and repair critically depend on axonal transport of vesicles and protein complexes, which is mediated in part by the molecular motor kinesin‐1. Adaptor proteins recruit kinesin‐1 to vesicles via direct association with kinesin heavy chain (KHC), the force‐generating component, or via the accessory light chain (KLC). Binding of adaptors to the motor is believed to engage the motor for microtubule‐based transport. We report that the adaptor protein Sunday Driver (syd, also known as JIP3 or JSAP1) interacts directly with KHC, in addition to and independently of its known interaction with KLC. Using an in vitro motility assay, …