Rab GTPases, tethers, and SNAREs work together to regulate Arabidopsis cell plate formation

Abstract

Cell plates are transient structures formed by the fusion of vesicles at the center of the dividing plane; furthermore, these are precursors to new cell walls and are essential for cytokinesis. Cell plate formation requires a highly coordinated process of cytoskeletal rearrangement, vesicle accumulation and fusion, and membrane maturation. Tethering factors have been shown to interact with the Ras superfamily of small GTP binding proteins (Rab GTPases) and soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs), which are essential for cell plate formation during cytokinesis and are fundamental for maintaining normal plant growth and development. In Arabidopsis thaliana, members of the Rab GTPases, tethers, and SNAREs are localized in cell plates, and mutations in the genes encoding these proteins result in typical cytokinesis-defective phenotypes, such as the formation of abnormal cell plates, multinucleated cells, and incomplete cell walls. This review highlights recent findings on vesicle trafficking during cell plate formation mediated by Rab GTPases, tethers, and SNAREs.

Four-dimensional quantitative analysis of cell plate development using lattice light sheet microscopy identifies robust transition points between growth phases

“…However, little is known about how these mechanisms are orchestrated (Drakakaki, 2015; Smertenko et al, 2017). Many GTPases are localized at the cell plate (Chow et al, 2008; Geldner et al, 2009; Qi et al, 2011; Qi and Zheng, 2013; Berson et al, 2014; Mayers et al, 2017; Shi et al, 2023), including the Rab-related GTPase RABA2a, which is involved in the delivery of trans -Golgi network derived vesicles to the leading edge of the cell plate. As such, RABA2a is considered a good marker for post-Golgi vesicles directing cargo to the cell plate (Chow et al, 2008).…”

The ArabidopsisSNAREcomplex genes regulate the early stages of pollen-stigma interactions

“…Within the secretory pathway, the final stages of vesicle delivery to the PM has been extensively investigated in eukaryotes, and key protein complexes have been identified to contribute to this final stage of secretion, including a tethering complex known as the exocyst complex followed by the SOLUBLE N-ETHYLMALEIMIDE-SENSITIVE FACTOR ADAPTOR PROTEIN RECEPTOR (SNARE) complex (Lipka et al 2007; Saeed et al 2019). Both protein complexes are essential for a large diversity of secretory events throughout the plant lifecycle, and corresponding mutants often display altered development and seedling lethality (Luo et al 2022; Shi et al 2023; Zarsky 2022; Zarsky et al 2020). The octameric exocyst complex is involved in tethering post-Golgi secretory vesicles at the plasma membrane (Saeed et al 2019; Zarsky 2022).…”

“…The SNARE complex carries out this function through protein-protein interactions between R-SNAREs on the vesicle membrane and Q-SNAREs on the target membrane (e.g. plasma membrane) to form a fusion complex for membrane fusion and release of the vesicle content (Lipka et al 2007; Shi et al 2023).…”

“…Many of these SNARE proteins are involved in other stages of vesicle trafficking in the endomembrane system (e.g. ER/Golgi, TGN/endosome, vacuole) with 23 SNARE proteins associated with vesicle fusion at the plasma membrane (Luo et al 2022; Shi et al 2023). As with many other Arabidopsis gene families, the SNARE gene family has single members that are critical for plant growth as well as closely related family members with overlapping roles.…”

“…One of the challenges in working with mutants for VAMP721, VAMP722, SYP121, SYP122 and SNAP33 is that these SNARE s have also been implicated in secretory pathways regulating Arabidopsis growth and development, and loss-of-function mutations lead to impaired growth and seedling lethality (Luo et al 2022; Shi et al 2023). The single vamp721 and vamp722 mutants are wildtype in appearance, but the vamp721 vamp722 double mutant displays a seedling-lethal phenotype with defects in cell plate formation during cytokinesis (Kwon et al 2008; Zhang et al 2011).…”