The microtubular preprophase band recruits Myosin XI to the division site for plant cytokinesis

Abstract

Plant growth is dependent on oriented cell divisions that employ the microtubular preprophase band (PPB) to position the cell plate. It has been intriguing how this transient cytoskeletal array imprints the spatial information to be read by the cytokinetic phragmoplast at later stages of mitotic cell division. InArabidopsis thaliana, we discovered that the PPB recruited the Myosin XI motor MYA1 to the cortical division site where it joined microtubule-associated proteins and motors to form a ring of prominent cytoskeletal assemblies which received the expanding phragmoplast. This regulatory function of MYA1 in phragmoplast guidance is dependent on intact actin filaments. The discovery of these assemblies revealed the mechanism underlying how two dynamic cytoskeletal networks govern PPB-dependent division plane orientation during vegetative growth in flowering plants.

De novo TANGLED1 recruitment from the phragmoplast to aberrant cell plate fusion sites in maize

“…In the absence of PPB-mediated recruitment, we observe TAN1–YFP accumulation at aberrant cell plate fusion sites that is partially dependent on actin filaments and O1. Consistent with this, when actin is disrupted in Arabidopsis root cells, TAN1, POK1 and myosin XI localization at the division site become diffuse ( Huang et al, 2022 preprint). Actin connects the leading edge of the phragmoplast with the division site through the action of myosin VIII in Physcomitrium patens ( Wu and Bezanilla, 2014 ) and is required for division plane positioning ( Mineyuki and Palevitz, 1990 ; Gallagher and Smith, 1999 ; Frank et al, 2003 ; Gilliland et al, 2003 ; Galatis and Apostolakos, 2004 ; Facette and Smith, 2012 ; Vaškebová et al, 2018 ).…”

“…Accumulation of TAN1–YFP at de novo cell plate insertion sites is partially dependent on O1. Given that TAN1 interacts with PHRAGMOPLAST ORIENTING KINESIN1 (POK1) and POK2 ( Müller et al, 2006 ; Rasmussen et al, 2011 ; Mills et al, 2022 ), and related kinesin 12s interact with myosin XI motor proteins ( Huang et al, 2022 preprint; Nan et al, 2023 ), we hypothesized that O1 might be necessary for TAN1–YFP accumulation. TAN1–YFP fluorescence intensity during telophase was reduced but not absent in both correctly oriented and de novo cell plate fusion sites in o1 mutants compared to wild-type siblings [ Fig.…”

De NovoTANGLED1 Recruitment to Aberrant Cell Plate Fusion Sites in Maize

“…In the absence of PPB-mediated recruitment, we observe TAN1-YFP accumulation at de novo cell plate fusion sites that is partially dependent on actin filaments and O1. Consistently, when actin is disrupted in Arabidopsis root cells, TAN1, POK1 and myosin XI division-site localization becomes diffuse (Huang et al ., 2022). Actin has been shown to connect the leading edge of the phragmoplast with the division site through the action of myosin VIII in Physcomitrium patens (Wu and Bezanilla, 2014) and is required for division plane positioning (Mineyuki and Palevitz, 1990; Gallagher and Smith, 1999; Frank, Cartwright and Smith, 2003; Gilliland et al ., 2003; Galatis and Apostolakos, 2004; Facette and Smith, 2012; Vaškebová, Šamaj and Ovecka, 2017).…”

“…We found that accumulation of TAN1-YFP at de novo cell plate insertion sites is partially dependent on the myosin XI O1. We hypothesized that since TAN1 interacts with PHRAGMOPLAST ORIENTING KINESIN1 (POK1) and POK2 (Müller, Han and Smith, 2006; Rasmussen, Sun and Smith, 2011; Mills, Morris and Rasmussen, 2022), and related kinesin 12s interact with myosin XI motor proteins including O1 (Huang et al ., 2022; Nan, Liang, et al ., 2023), O1 might be necessary for TAN1-YFP accumulation. TAN1-YFP fluorescence intensity during telophase was reduced but not absent in both correctly oriented and de novo cell plate fusion sites in o1 compared to wild-type siblings (Figure 4A-B, p = 1.02e-12, One-way ANOVA followed by Tukey’s HSD).…”

The Calmodulin-like proteins, CML13 and CML14 Function as Myosin Light Chains for the Class XI Myosins inArabidopsis

“…Indeed, the engineering of Arabidopsis myosin XI-2 with the faster Chara braunii myosin XI motor domain resulted in increased Arabidopsis and Camelina sativa growth owing to faster cytoplasmic transport and larger cell sizes (Tominaga et al, 2013;Duan et al, 2020). Further, myosin XIK and XI-1 where shown to play a role during cell division (Abu-Abied et al, 2018;Huang et al, 2024). Some of the other Arabidopsis myosin XI family members have specialized functions.…”