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Full-Text Articles in Life Sciences
The Arabidopsis Kinesin-4, Fra1, Requires A High Level Of Processive Motility To Function Correctly, Anindya Ganguly, Logan Demott, Ram Dixit
The Arabidopsis Kinesin-4, Fra1, Requires A High Level Of Processive Motility To Function Correctly, Anindya Ganguly, Logan Demott, Ram Dixit
Biology Faculty Publications & Presentations
Processivity is important for kinesins that mediate intracellular transport. Structure–function analyses of N-terminal kinesins (i.e. kinesins comprising their motor domains at the N-terminus) have identified several non-motor regions that affect processivity in vitro. However, whether these structural elements affect kinesin processivity and function in vivo is not known. Here, we used an Arabidopsis thaliana kinesin-4, called Fragile Fiber 1 (FRA1, also known as KIN4A), which is thought to mediate vesicle transport, to test whether mutations that alter processivity in vitro lead to similar changes in behavior in vivo and whether processivity is important for the function of FRA1. We …
The Fragile Fiber1 Kinesin Contributes To Cortical Microtubule-Mediated Trafficking Of Cell Wall Components, Chuanmei Zhu, Anindya Ganguly, Tobias I. Baskin, Daniel D. Mcclosky, Charles T. Anderson, Cliff Foster, Kristoffer A. Meunier, Ruth Okamoto, Howard Berg, Ram Dixit
The Fragile Fiber1 Kinesin Contributes To Cortical Microtubule-Mediated Trafficking Of Cell Wall Components, Chuanmei Zhu, Anindya Ganguly, Tobias I. Baskin, Daniel D. Mcclosky, Charles T. Anderson, Cliff Foster, Kristoffer A. Meunier, Ruth Okamoto, Howard Berg, Ram Dixit
Biology Faculty Publications & Presentations
The cell wall consists of cellulose microfibrils embedded within a matrix of hemicellulose and pectin. Cellulose microfibrils are synthesized at the plasma membrane, whereas matrix polysaccharides are synthesized in the Golgi apparatus and secreted. The trafficking of vesicles containing cell wall components is thought to depend on actin-myosin. Here, we implicate microtubules in this process through studies of the kinesin-4 family member, Fragile Fiber1 (FRA1). In an fra1-5 knockout mutant, the expansion rate of the inflorescence stem is halved compared with the wild type along with the thickness of both primary and secondary cell walls. Nevertheless, cell walls in fra1-5 …
Mechanisms For Regulation Of Plant Kinesins, Anindya Ganguly, Ram Dixit
Mechanisms For Regulation Of Plant Kinesins, Anindya Ganguly, Ram Dixit
Biology Faculty Publications & Presentations
Throughout the eukaryotic world, kinesins serve as molecular motors for the directional transport of cellular cargo along microtubule tracks. Plants contain a large number of kinesins that have conserved as well as specialized functions. These functions depend on mechanisms that regulate when, where and what kinesins transport. In this review, we highlight recent studies that have revealed conserved modes of regulation between plant kinesins and their non-photosynthetic counterparts. These findings lay the groundwork for understanding how plant kinesins are differentially engaged in various cellular processes that underlie plant growth and development.
Functions Of The Arabidopsis Kinesin Superfamily Of Microtubule-Based Motor Proteins, Chuanmei Zhu, Ram Dixit
Functions Of The Arabidopsis Kinesin Superfamily Of Microtubule-Based Motor Proteins, Chuanmei Zhu, Ram Dixit
Biology Faculty Publications & Presentations
Plants possess a large number of microtubule-based kinesin motor proteins. While the kinesin-2, 3, 9, and 11 families are absent from land plants, the kinesin-7 and 14 families are greatly expanded. In addition, some kinesins are specifically present only in land plants. The distinctive inventory of plant kinesins suggests that kinesins have evolved to perform specialized functions in plants. Plants assemble unique microtubule arrays during their cell cycle, including the interphase cortical microtubule array, preprophase band, anastral spindle and phragmoplast. In this review, we explore the functions of plant kinesins from a microtubule array viewpoint, focusing mainly on Arabidopsis kinesins. …
Single Molecule Analysis Of The Arabidopsis Fra1 Kinesin Shows That It Is A Functional Motor Protein With Unusually High Processivity, Chuanmei Zhu, Ram Dixit
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 …