A unifying new model of cytokinesis for the dividing plant and animal cells

Abstract

Cytokinesis ensures proper partitioning of the nucleocytoplasmic contents into two daughter cells. It has generally been thought that cytokinesis is accomplished differently in animals and plants because of the differences in the preparatory phases, into the centrosomal or acentrosomal nature of the process, the presence or absence of rigid cell walls, and on the basis of 'outside-in' or 'inside-out' mechanism. However, this long-standing paradigm needs further reevaluation based on new findings. Recent advances reveal that plant cells, similarly to animal cells, possess astral microtubules that regulate the cell division plane. Furthermore, endocytosis has been found to be important for cytokinesis in animal and plant cells: vesicles containing endocytosed cargo provide material for the cell plate formation in plants and for closure of the midbody channel in animals. Thus, although the preparatory phases of the cell division process differ between plant and animal cells, the later phases show similarities. We unify these findings in a model that suggests a conserved mode of cytokinesis.

Chemical Effectors of Plant Endocytosis and Endomembrane Trafficking

“…Another inhibitor Tyrphostin A23, but not Tyrphostin A51, interferes with the recognition of the YxxA internalization motif in the cytosolic domain of plasma membrane receptors by the l-adaptin of the AP-2 adaptor complex (Titapiwatanakun et al 2009;Dambournet et al 2011) and is widely used as a competitive inhibitor of receptor Tyr kinases in mammalian cells due to its structural similarity to Tyr (Aniento and Robinson 2005). In plants, tyrphostin A23 has been reported to inhibit endocytosis in protoplasts (Ortiz-Zapater et al 2006), prevent the accumulation of PIN2 in BFA compartments in Arabidopsis roots (Dhonukshe et al 2007a), and interfere with cytokinesis and cell plate formation (Reichardt et al 2007), indicating that both endocytosis and Golgi-based secretion are targets of the inhibitor. Other inhibitors, such as the phosphatidylinositol-3/4 kinase (PI-3/4 kinase) inhibitor wortmannin, interfere with protein trafficking to the plant vacuole (Dhonukshe et al 2008b;Takáč et al 2012) and with endocytosis (Irani and Russinova 2009).…”

“…This mechanism ensures the dynamic regulation of PIN polarity in response to developmental and environmental stimulus, for example, in the rapid reorientation of PIN3 in columella cells during gravitropic response (Norambuena et al 2009;Kleine-Vehn et al 2010) and switch of PIN polarity during embryogenesis (Benková et al 2003;Beutler et al 2009). Mutations of Rab5 or clathrin subunits result in disruption of endocytosis and auxin-related developmental defects (Dhonukshe et al 2007a(Dhonukshe et al , 2008a. Endocytosis also plays a key role in signal transduction processes.…”

“…Dosage dependence and reversibility provide the means to circumvent problems of lethality and redundancy (Drakakaki et al 2009;Hicks and Raikhel 2009;Norambuena et al 2009). Chemical genomics also offers the ideal ability to study dynamic endomembrane trafficking processes in real time which often is within minutes (Dhonukshe et al 2007a). This can be achieved by the observing interference of GFP-tagged protein trafficking through endomembrane compartments via confocal microscopy (Drakakaki et al 2011;Hicks and Raikhel 2012).…”

“…Endosomes are essential compartments for protein targeting, recycling, and degradation, and they are of vital importance for processes including auxin signalling and transport (Dhonukshe et al 2006(Dhonukshe et al , 2007aSauer and Kleine-Vehn 2011), BR signalling (Geldner et al 2007;Robert et al 2008), boron uptake (Takano et al 2008), blue light responses (Christie 2007), and plant immunity (Robatzek et al 2006;Sharfman et al 2011) among others.…”

SCAMPs Highlight the Developing Cell Plate during Cytokinesis in Tobacco BY-2 Cells

“…In higher plants, cytokinesis involves the formation of a cell plate through the fusion of vesicles at its centrifugally expanding periphery (Jü rgens, 2005;Hong and Verma, 2008). It is generally considered to be a different cell cycle event from that occurring in mammals, although this notion has recently been challenged (Dhonukshe et al, 2007). Cytokinesis is a complex of several interconnecting processes, including a positioning machinery that determines the plane of division, regulatory factors involved in the formation and movement of the phragmoplast, and membrane trafficking events bringing membrane to and from the developing cell plate (Reichardt et al, 2007;Walker et al, 2007).…”