Plant cytokinesis: a tale of membrane traffic and fusion

2015 ◽  
Vol 43 (1) ◽  
pp. 73-78 ◽  
Author(s):  
Gerd Jürgens ◽  
Misoon Park ◽  
Sandra Richter ◽  
Sonja Touihri ◽  
Cornelia Krause ◽  
...  
Keyword(s):  
Higher Plants ◽  
Membrane Vesicles ◽  
Cell Plate ◽  
Division Plane ◽  
Daughter Cells ◽  
Division Site ◽  
Plant Cytokinesis ◽  
M Phase ◽  
Golgi Network ◽  
Sm Protein

Cytokinesis separates the forming daughter cells. Higher plants have lost the ability to constrict the plasma membrane (PM) in the division plane. Instead, trans-Golgi network (TGN)-derived membrane vesicles are targeted to the centre of the division plane and generate, by homotypic fusion, the partitioning membrane named cell plate (CP). The CP expands in a centrifugal fashion until its margin fuses with the PM at the cortical division site. Mutant screens in Arabidopsis have identified a cytokinesis-specific syntaxin named KNOLLE and an interacting Sec1/Munc18 (SM) protein named KEULE both of which are required for vesicle fusion during cytokinesis. KNOLLE is only made during M-phase, targeted to the division plane and degraded in the vacuole at the end of cytokinesis. Here we address mechanisms of KNOLLE trafficking and interaction of KNOLLE with different soluble N-ethylmaleimide-sensitive factor (NSF) attachment protein (SNAP) receptor (SNARE) partners and with SM-protein KEULE, ensuring membrane fusion in cytokinesis.

Relationship between preprophase band organization, F-actin and the division site in Allium

1990 ◽  
Vol 97 (2) ◽  
pp. 283-295
Author(s):  
Y. MINEYUKI ◽  
B. A. PALEVITZ
Keyword(s):  
Higher Plants ◽  
Preprophase Band ◽  
Cell Plate ◽  
Mitotic Apparatus ◽  
Division Plane ◽  
Division Site ◽  
Dividing Cells ◽  
G2 Phase

The preprophase band (PPB) of microtubules (Mts), which appears in the G2 phase of the cell cycle in higher plants but disappears well before the end of karyokinesis, is implicated in the determination of the division plane because its location marks the site at which the phragmoplast/cell plate will fuse with the parental plasmalemma during cytokinesis. The PPB first appears as a rather wide array, which progressively narrows before or during prophase. Actin-containing microfilaments (Mfs) have recently been reported in the PPB, but the role of these elements in PPB organization and/or function remains unclear. The present study employed fluorescence and pharmacological methods in symmetrically and asymmetrically dividing epidermal cells of Allium to probe this problem. Our results show that PPBs in cells treated with 2–200μM cytochalasin D (CD) are still transversely aligned but remain two to three times wider than mature bands in control cells. Treatment for 0.5 h at 20 μM is sufficient to make the PPBs abnormally widel Premitotic nuclear migration in asymmetrically dividing cells is also inhibited by CD, as is the positioning of the mitotic apparatus and the new cell plate. The plate is still transverse, however. Band-like arrays of cortical Mfs become evident in most interphase cells by prophase. The band remains quite wide compared to the final dimensions of the Mt PPB, and clearly encompasses it. Levels of CD as high as 200μM decrease the number of cells with transverse actin bands, although a majority still retain them. Other F-actin arrays are disrupted by the drug. Thus, while CD does not inhibit the formation of an initial, broad, transverse PPB in most cells, it does prevent the narrowing process that defines the precise division site. The role of actin in this effect is discussed.

Cytosolic And Membrane Proteins In Plant Cytokinesis

1999 ◽  
Vol 5 (S2) ◽  
pp. 1248-1249
Author(s):  
S. Y. Bednarek ◽  
C. Dickey
Keyword(s):  
Cell Wall ◽  
De Novo ◽  
Higher Plants ◽  
Cell Plate ◽  
Equatorial Region ◽  
Yeast Cells ◽  
Daughter Cells ◽  
Cytoskeletal Structure ◽  
Plant Cytokinesis ◽  
Common Cell

The mechanism of cytokinesis in higher plants is distinct from that of animal and yeast cells. Dividing plant cells are separated by the de novo construction of the cell-plate across the inside of the cell. Assembly of this new organelle is directed by a specialized cytoskeletal structure called the phragmoplast, a unique macromolecular scaffold that appears late in mitosis and is composed of intermediate filaments, microfilaments, and microtubules. Secretory vesicles are guided along the phragmoplast cytoskeleton toward the equatorial region of the structure where they coalesce and fuse to form a membranous tubular-vesicular network within which cell wall biosynthesis is initiated. A smoother more plate-like structure develops and extends radially outward as additional vesicles are added to the growing margin of the cell-plate until it ultimately fuses with the parental plasma membrane yielding two daughter cells separated by a common cell wall and extracellular space.

Division Plane Establishment and Cytokinesis

2019 ◽  
Vol 70 (1) ◽  
pp. 239-267 ◽  
Author(s):  
Pantelis Livanos ◽  
Sabine Müller
Keyword(s):  
Secretory Pathway ◽  
Preprophase Band ◽  
Cell Plate ◽  
Division Plane ◽  
Spatial Reference ◽  
Division Site ◽  
Eukaryotic Proteins ◽  
Plate Formation ◽  
Membrane Compartment ◽  
Cytoplasmic Content

Plant cells divide their cytoplasmic content by forming a new membrane compartment, the cell plate, via a rerouting of the secretory pathway toward the division plane aided by a dynamic cytoskeletal apparatus known as the phragmoplast. The phragmoplast expands centrifugally and directs the cell plate to the preselected division site at the plasma membrane to fuse with the parental wall. The division site is transiently decorated by the cytoskeletal preprophase band in preprophase and prophase, whereas a number of proteins discovered over the last decade reside continuously at the division site and provide a lasting spatial reference for phragmoplast guidance. Recent studies of membrane fusion at the cell plate have revealed the contribution of functionally conserved eukaryotic proteins to distinct stages of cell plate biogenesis and emphasize the coupling of cell plate formation with phragmoplast expansion. Together with novel findings concerning preprophase band function and the setup of the division site, cytokinesis and its spatial control remain an open-ended field with outstanding and challenging questions to resolve.

scholarly journals Functional characterization of the KNOLLE-interacting t-SNARE AtSNAP33 and its role in plant cytokinesis

2001 ◽  
Vol 155 (2) ◽  
pp. 239-250 ◽  
Author(s):  
Maren Heese ◽  
Xavier Gansel ◽  
Liliane Sticher ◽  
Peter Wick ◽  
Markus Grebe ◽  
...  
Keyword(s):  
Cell Division ◽  
Membrane Fusion ◽  
Functional Characterization ◽  
Cell Plate ◽  
Yeast Two Hybrid ◽  
Division Plane ◽  
Plant Cytokinesis ◽  
Cell Plate Formation ◽  
Plate Formation ◽  
Two Hybrid

Cytokinesis requires membrane fusion during cleavage-furrow ingression in animals and cell plate formation in plants. In Arabidopsis, the Sec1 homologue KEULE (KEU) and the cytokinesis-specific syntaxin KNOLLE (KN) cooperate to promote vesicle fusion in the cell division plane. Here, we characterize AtSNAP33, an Arabidopsis homologue of the t-SNARE SNAP25, that was identified as a KN interactor in a yeast two-hybrid screen. AtSNAP33 is a ubiquitously expressed membrane-associated protein that accumulated at the plasma membrane and during cell division colocalized with KN at the forming cell plate. A T-DNA insertion in the AtSNAP33 gene caused loss of AtSNAP33 function, resulting in a lethal dwarf phenotype. atsnap33 plantlets gradually developed large necrotic lesions on cotyledons and rosette leaves, resembling pathogen-induced cellular responses, and eventually died before flowering. In addition, mutant seedlings displayed cytokinetic defects, and atsnap33 in combination with the cytokinesis mutant keu was embryo lethal. Analysis of the Arabidopsis genome revealed two further SNAP25-like proteins that also interacted with KN in the yeast two-hybrid assay. Our results suggest that AtSNAP33, the first SNAP25 homologue characterized in plants, is involved in diverse membrane fusion processes, including cell plate formation, and that AtSNAP33 function in cytokinesis may be replaced partially by other SNAP25 homologues.

scholarly journals SNARE complexes of different composition jointly mediate membrane fusion in Arabidopsis cytokinesis

2013 ◽  
Vol 24 (10) ◽  
pp. 1593-1601 ◽  
Author(s):  
Farid El Kasmi ◽  
Cornelia Krause ◽  
Ulrike Hiller ◽  
York-Dieter Stierhof ◽  
Ulrike Mayer ◽  
...  
Keyword(s):  
Membrane Fusion ◽  
Membrane Vesicles ◽  
Snare Complex ◽  
The Other ◽  
Division Plane ◽  
Daughter Cells ◽  
Protein Receptor ◽  
Sensitive Factor ◽  
Membrane Type ◽  
Cell Division Plane

Membrane fusion is mediated by soluble N-ethylmaleimide–sensitive factor attachment protein receptor (SNARE) complexes. Although membrane fusion is required for separating daughter cells in eukaryotic cytokinesis, the SNARE complexes involved are not known. In plants, membrane vesicles targeted to the cell division plane fuse with one another to form the partitioning membrane, progressing from the center to the periphery of the cell. In Arabidopsis, the cytokinesis-specific Qa-SNARE KNOLLE interacts with two other Q-SNAREs, SNAP33 and novel plant-specific SNARE 11 (NPSN11), whose roles in cytokinesis are not clear. Here we show by coimmunoprecipitation that KNOLLE forms two SNARE complexes that differ in composition. One complex is modeled on the trimeric plasma membrane type of SNARE complex and includes, in addition to KNOLLE, the promiscuous Qb,c-SNARE SNAP33 and the R-SNARE vesicle-associated membrane protein (VAMP) 721,722, also involved in innate immunity. In contrast, the other KNOLLE-containing complex is tetrameric and includes Qb-SNARE NPSN11, Qc-SNARE SYP71, and VAMP721,722. Elimination of only one or the other type of KNOLLE complex by mutation, including the double mutant npsn11 syp71, causes a mild or no cytokinesis defect. In contrast, the two double mutants snap33 npsn11 and snap33 syp71 eliminate both types of KNOLLE complexes and display knolle-like cytokinesis defects. Thus the two distinct types of KNOLLE complexes appear to jointly mediate membrane fusion in Arabidopsis cytokinesis.

scholarly journals Delivery of endocytosed proteins to the cell–division plane requires change of pathway from recycling to secretion

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Sandra Richter ◽  
Marika Kientz ◽  
Sabine Brumm ◽  
Mads Eggert Nielsen ◽  
Misoon Park ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Cell Division ◽  
Membrane Trafficking ◽  
Nucleotide Exchange ◽  
Division Plane ◽  
Plant Cytokinesis ◽  
Guanine Nucleotide Exchange ◽  
Cargo Delivery ◽  
Golgi Network ◽  
Cell Division Plane

Membrane trafficking is essential to fundamental processes in eukaryotic life, including cell growth and division. In plant cytokinesis, post-Golgi trafficking mediates a massive flow of vesicles that form the partitioning membrane but its regulation remains poorly understood. Here, we identify functionally redundant Arabidopsis ARF guanine-nucleotide exchange factors (ARF-GEFs) BIG1–BIG4 as regulators of post-Golgi trafficking, mediating late secretion from the trans-Golgi network but not recycling of endocytosed proteins to the plasma membrane, although the TGN also functions as an early endosome in plants. In contrast, BIG1-4 are absolutely required for trafficking of both endocytosed and newly synthesized proteins to the cell–division plane during cytokinesis, counteracting recycling to the plasma membrane. This change from recycling to secretory trafficking pathway mediated by ARF-GEFs confers specificity of cargo delivery to the division plane and might thus ensure that the partitioning membrane is completed on time in the absence of a cytokinesis-interphase checkpoint.

scholarly journals Chromosome segregation drives division site selection inStreptococcus pneumoniae

2016 ◽  
Author(s):  
Renske van Raaphorst ◽  
Morten Kjos ◽  
Jan-Willem Veening
Keyword(s):  
Cell Division ◽  
Chromosome Segregation ◽  
Site Selection ◽  
Bacterial Cell Division ◽  
Division Plane ◽  
Canonical Systems ◽  
Daughter Cells ◽  
Division Site ◽  
Additional Protein ◽  
Site Control

AbstractAccurate spatial and temporal positioning of the tubulin-like protein FtsZ is key for proper bacterial cell division.Streptococcus pneumoniae(pneumococcus) is an oval-shaped, symmetrically dividing human pathogen lacking the canonical systems for division site control (nucleoid occlusion and the Min-system). Recently, the early division protein MapZ was identified and implicated in pneumococcal division site selection. We show that MapZ is important for proper division plane selection; thus the question remains what drives pneumococcal division site selection. By mapping the cell cycle in detail, we show that directly after replication both chromosomal origin regions localize to the future cell division sites, prior to FtsZ. Perturbing the longitudinal chromosomal organization by mutating the condensin SMC, by CRISPR/Cas9-mediated chromosome cutting or by poisoning DNA decatenation resulted in mistiming of MapZ and FtsZ positioning and subsequent cell elongation. Together, we demonstrate an intimate relationship between DNA replication, chromosome segregation and division site selection in the pneumococcus, providing a simple way to ensure equally sized daughter cells without the necessity for additional protein factors.

scholarly journals Control of plant cytokinesis by an NPK1–mediated mitogen–activated protein kinase cascade

2002 ◽  
Vol 357 (1422) ◽  
pp. 767-775 ◽  
Author(s):  
Takashi Soyano ◽  
Masaki Ishikawa ◽  
Ryuichi Nishihama ◽  
Satoshi Araki ◽  
Mayumi Ito ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Plant Cells ◽  
Cell Plate ◽  
Mitogen Activated Protein Kinase ◽  
Cross Wall ◽  
Daughter Cells ◽  
Plant Cytokinesis ◽  
Mitogen Activated Protein ◽  
Kinase Cascade ◽  
Protein Kinase Cascade

Cytokinesis is the last essential step in the distribution of genetic information to daughter cells and partition of the cytoplasm. In plant cells, various proteins have been found in the phragmoplast, which corresponds to the cytokinetic apparatus, and in the cell plate, which corresponds to a new cross wall, but our understanding of the functions of these proteins in cytokinesis remains incomplete. Reverse genetic analysis of NPK1 MAPKKK (nucleus– and phragmoplast–localized protein kinase 1 mitogen–activated protein kinase kinase kinase) and investigations of factors that might be functionally related to NPK1 have helped to clarify new aspects of the mechanisms of cytokinesis in plant cells. In this review, we summarize the evidence for the involvement of NPK1 in cytokinesis. We also describe the characteristics of a kinesin–like protein and the homologue of a mitogen–activated protein kinase that we identified recently, and we discuss possible relationships among these proteins in cytokinesis.

scholarly journals Cdc42 GTPase activating proteins Rga4 and Rga6 coordinate septum synthesis and membrane trafficking at the division plane during cytokinesis

2021 ◽  
Author(s):  
Bethany F Campbell ◽  
Brian S Hercyk ◽  
Ashlei R Williams ◽  
Emalyn S San Miguel ◽  
Haylee G Young ◽  
...  
Keyword(s):  
Membrane Trafficking ◽  
Membrane Vesicles ◽  
Membrane Structures ◽  
Division Plane ◽  
Septum Formation ◽  
Division Site ◽  
Gtpase Activating Proteins ◽  
Primary Septum ◽  
Separate Electron ◽  
Specific Membrane

Fission yeast cytokinesis is driven by simultaneous septum synthesis, membrane furrowing and actomyosin ring constriction. The septum consists of a primary septum flanked by secondary septa. First, delivery of the glucan synthase Bgs1 and membrane vesicles initiate primary septum synthesis and furrowing. Next, Bgs4 is delivered for secondary septum formation. It is unclear how septum synthesis is coordinated with membrane furrowing. Cdc42 promotes delivery of Bgs1 but not Bgs4. We find that after primary septum initiation, Cdc42 inactivators Rga4 and Rga6 localize to the division site. In rga4Δrga6Δ mutants Cdc42 activity is enhanced during late cytokinesis and cells take longer to separate. Electron micrographs of the division site in these mutants exhibit malformed septum with irregular membrane structures. These mutants have a larger division plane with enhanced Bgs1 delivery but fail to enhance accumulation of Bgs4 and several exocytic proteins. Additionally, these mutants show endocytic defects at the division site. This suggests that Cdc42 regulates only specific membrane trafficking events. Our data indicate that while active Cdc42 promotes primary septum synthesis, as cytokinesis progresses Rga4 and Rga6 localize to the division site to decrease Cdc42 activity. This couples specific membrane trafficking events with septum formation to allow proper septum morphology.

The role of F-actin in determining the division plane of carrot suspension cells. Drug studies

Development ◽  
1988 ◽  
Vol 102 (1) ◽  
pp. 211-221 ◽  
Author(s):  
C.W. Lloyd ◽  
J.A. Traas
Keyword(s):  
Preprophase Band ◽  
Cell Plate ◽  
Suspension Cells ◽  
Mitotic Apparatus ◽  
Division Plane ◽  
Division Site ◽  
Cytoplasmic Actin ◽  
Spindle Poles ◽  
Extraction Buffer ◽  
Actin Cables

Following the report that a network of F-actin is associated with the nucleus throughout the division cycle, we have examined the involvement of F-actin in determining the division plane of carrot suspension cells. This was achieved by treating cells with drugs and then staining the unfixed cells with rhodaminyl lysine phallotoxin in detergent extraction buffer. In interphase, actin cables radiate from the nucleus but at the cortex become more or less transversely arranged in the pattern already known for cortical microtubules. Concentration of the cortical F-actin into a band at preprophase draws most of the nucleus- associated actin into a transvacuolar disc, thereby forming the phragmosome within which mitosis and cytokinesis occur. In addition to this transversely aligned structure, F-actin is also associated with the spindle poles during mitosis but these filaments tend to align at right angles to the phragmosomal actin. F-actin therefore defines transverse and longitudinal vectors as division approaches. Depolymerization of F-actin with cytochalasin D can cause the spindle axis to reorientate such that the pole-pole axis comes to lie, abnormally, parallel with the phragmosome. The cytokinetic apparatus (the phragmoplast) develops centrifugally within the phragmosome. There has been considerable speculation on the nature of the elements that guide the phragmoplast to the cortical site previously occupied by the preprophase band of microtubules. This study demonstrates that F-actin bridges the leading margin of the outgrowing phragmoplast to the opposing cortex. Radial actin strands therefore provide a ‘memory’ of the predetermined division plane whose perimeter had been marked at preprophase by a band composed of microtubules and F-actin. This relationship was perturbed with the herbicide, chloroisopropylphenyl carbamate. Preprophase bands of actin appear to form normally in herbicide-treated cells. However, cytokinesis does not occur within this predicted plane since the drug perturbs the mitotic spindle, forming three nuclei which become separated by Y-shaped, actin-containing phragmoplasts. Cytoplasmic actin strands connect the edges of the phragmoplast to the cortex. It is suggested that the irregular distribution of F-actin, which radiates from the herbicide-altered mitotic apparatus, provides alternative paths for outgrowth of the abnormal phragmoplasts. Caffeine is known to cause failure of cell plate formation. But apart from inducing cytoplasmic ‘starbursts’ of F-actin in interphase cells it does not appear to have any effect on F-actin-containing division structures. It is concluded that the formation of a transvacuolar phragmosome, spindle alignment and the ‘correct’ outgrowth of a planar cytokinetic apparatus to the predetermined boundary of the division site all involve F-actin.

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