Katanin: A Sword Cutting Microtubules for Cellular, Developmental, and Physiological Purposes

Abstract

KATANIN is a well-studied microtubule severing protein affecting microtubule organization and dynamic properties in higher plants. By regulating mitotic and cytokinetic and cortical microtubule arrays it is involved in the progression of cell division and cell division plane orientation. KATANIN is also involved in cell elongation and morphogenesis during plant growth. In this way KATANIN plays critical roles in diverse plant developmental processes including the development of pollen, embryo, seed, meristem, root, hypocotyl, cotyledon, leaf, shoot, and silique. KATANIN-dependent microtubule regulation seems to be under the control of plant hormones. This minireview provides an overview on available KATANIN mutants and discusses advances in our understanding of KATANIN biological roles in plants.

Tissue-Specific Transcriptome Analysis Reveals Candidate Transcripts Associated with the Process of Programmed B Chromosome Elimination in Aegilops speltoides

“…Furthermore, a transcript (Bplus_DN37268_c0_g1_i1) encoding Katanin p60 ATPase-containing subunit A-like 1 (p60 katanin-like 1) was highly up-regulated in the Bplus condition (log 2 FC of 6.16, FDR-corrected p -value of 0.0009). Katanin is the only defined microtubule severing protein affecting microtubule organization in higher plants [ 20 ].…”

Cortical microtubule orientation in Arabidopsis thaliana root meristematic zone depends on cell division and requires severing by katanin

“…5c). Severing by p60-katanin is pivotal for the organization of microtubule arrays in interphase and mitotic [10, 11, 17–20] cells. However, it has been suggested that, although critical for cortical microtubule orientation in fast elongating cells, severing is not important in interphase meristematic cells, the microtubule pattern of which was described as random [21, 22].…”

“…Seeds of A. thaliana , wild-type (Col-0) and the p60-katanin mutants fra2 , lue1 and ktn1/2 , were surface sterilized and grown on solid agar medium as previously described [10]. All the chemicals and reagents used in this study were purchased from Sigma (Taufkirchen, Germany), Merck (Darmstadt, Germany) and Applichem (Darmstadt, Germany), and all the following steps were carried out at room temperature unless stated otherwise.…”

“…By means of this software the angular distribution of cortical microtubules could be determined and accordingly inferred to their orientation either as “transverse”, at angles of 90° or 270°, “longitudinal” at angles of 0° or 180° or “random” at angles between 0° and 180° as described in [10]. Statistical analysis (ANOVA with Dunnett’s multiple comparison test) of cell length in untreated and aphidicolin-treated roots was performed with GraphPad (San Diego, CA, USA), with significance at p  < 0.05.…”

The Winner Takes It All: Auxin—The Main Player during Plant Embryogenesis

“…It is possible that other proteins regulating microtubule behavior are responsible for cytoskeleton rearrangements during embryo development and I concentrate on two proteins whose specific functions during embryogenesis still need elucidation. Katanin, the microtubule-severing protein, was found to be indispensable for the transverse microtubule alignment during postembryonic development [73,74] and disorders of embryogenesis in katanin mutants were previously shown [75]. Although auxin activates the katanin activity via the ROP6-RIC1 pathway [54,73,76,77], a high auxin level induces calcium release from intracellular reservoirs and the external space [78] which at an elevated concentration may inhibit the katanin activity without changing its ability to bind substrates [79].…”