scholarly journals TANGLED1 mediates microtubule interactions that may promote division plane positioning in maize

2020 ◽  
Vol 219 (8) ◽  
Author(s):  
Pablo Martinez ◽  
Ram Dixit ◽  
Rachappa S. Balkunde ◽  
Antonia Zhang ◽  
Seán E. O’Leary ◽  
...  
Keyword(s):  
Critical Role ◽  
Preprophase Band ◽  
Microtubule Organization ◽  
Division Plane ◽  
Plane Orientation ◽  
Division Site ◽  
Structural Framework ◽  
Cell Shapes ◽  
Division Plane Orientation

The microtubule cytoskeleton serves as a dynamic structural framework for mitosis in eukaryotic cells. TANGLED1 (TAN1) is a microtubule-binding protein that localizes to the division site and mitotic microtubules and plays a critical role in division plane orientation in plants. Here, in vitro experiments demonstrate that TAN1 directly binds microtubules, mediating microtubule zippering or end-on microtubule interactions, depending on their contact angle. Maize tan1 mutant cells improperly position the preprophase band (PPB), which predicts the future division site. However, cell shape–based modeling indicates that PPB positioning defects are likely a consequence of abnormal cell shapes and not due to TAN1 absence. In telophase, colocalization of growing microtubules ends from the phragmoplast with TAN1 at the division site suggests that TAN1 interacts with microtubule tips end-on. Together, our results suggest that TAN1 contributes to microtubule organization to ensure proper division plane orientation.

scholarly journals TANGLED1 mediates interactions between microtubules that may promote spindle organization and phragmoplast guidance to the division site in maize

2019 ◽  
Author(s):  
Pablo Martinez ◽  
Ram Dixit ◽  
Rachappa S. Balkunde ◽  
Seán E. O’Leary ◽  
Kenneth A. Brakke ◽  
...  
Keyword(s):  
Critical Role ◽  
Preprophase Band ◽  
Microtubule Organization ◽  
Division Plane ◽  
Plane Orientation ◽  
Division Site ◽  
Structural Framework ◽  
Cell Shapes ◽  
Division Plane Orientation

AbstractThe microtubule cytoskeleton serves as a dynamic structural framework for mitosis in eukaryotic cells. TANGLED1 (TAN1) is a microtubule-binding protein that localizes to the division site and mitotic microtubules and plays a critical role in division plane orientation in plants. Here, in vitro experiments demonstrate that TAN1 directly binds microtubules, mediating microtubule zippering or end-on microtubule interactions, depending on their contact angle. Maize tan1 mutant cells improperly position the preprophase band (PPB), which predicts the future division site. However, cell-shape-based modeling indicates that PPB positioning defects are likely a consequence of abnormal cell shapes and not due to TAN1 absence. Spindle defects in the tan1 mutant suggest that TAN1-mediated microtubule zippering may contribute to metaphase spindle organization. In telophase, co-localization of growing microtubules ends from the phragmoplast with TAN1 at the division site suggests that TAN1 interacts with microtubule tips end-on. Together, our results suggest that TAN1 contributes to spindle and phragmoplast microtubule organization to ensure proper division plane orientation.

scholarly journals Predicting division planes of three-dimensional cells by soap-film minimization

2017 ◽  
Author(s):  
Pablo Martinez ◽  
Lindy A. Allsman ◽  
Kenneth A. Brakke ◽  
Christopher Hoyt ◽  
Jordan Hayes ◽  
...  
Keyword(s):  
Developmental Regulation ◽  
Three Dimensional ◽  
Soap Film ◽  
Preprophase Band ◽  
Animal Cells ◽  
Division Plane ◽  
Plane Orientation ◽  
Division Site ◽  
Division Plane Orientation

AbstractOne key aspect of cell division in multicellular organisms is the orientation of the division plane. Proper division plane establishment contributes to normal organization of the plant body. To determine the importance of cell geometry in division plane orientation, we designed a threedimensional probabilistic mathematical modeling approach to directly test the century-old hypothesis that cell divisions mimic “soap-film minima” or that daughter cells have equal volume and the resulting division plane is a local surface area minimum. Predicted division planes were compared to a plant microtubule array that marks the division site, the preprophase band (PPB). PPB location typically matched one of the predicted divisions. Predicted divisions offset from the PPB occurred when a neighboring cell wall or PPB was observed directly adjacent to the predicted division site, to avoid creating a potentially structurally unfavorable four-way junction. By comparing divisions of differently shaped plant and animal cells to divisions simulated in silico, we demonstrate the generality of this model to accurately predict in vivo division. This powerful model can be used to separate the contribution of geometry from mechanical stresses or developmental regulation in predicting division plane orientation.

IQ67 DOMAIN proteins facilitate preprophase band formation and division-plane orientation

Nature Plants ◽  
2021 ◽  
Author(s):  
Pratibha Kumari ◽  
Pradeep Dahiya ◽  
Pantelis Livanos ◽  
Luise Zergiebel ◽  
Malte Kölling ◽  
...  
Keyword(s):  
Preprophase Band ◽  
Band Formation ◽  
Division Plane ◽  
Plane Orientation ◽  
Division Plane Orientation ◽  
Iq67 Domain

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 Critical role for cold shock protein YB-1 in cytokinesis

2020 ◽  
Author(s):  
Sunali Mehta ◽  
Michael Algie ◽  
Tariq Al-Jabri ◽  
Cushla McKinney ◽  
Srinivasaraghavan Kannan ◽  
...  
Keyword(s):  
Cell Division ◽  
Cancer Progression ◽  
Cold Shock ◽  
Binding Protein ◽  
Critical Role ◽  
Confocal Imaging ◽  
Cold Shock Protein ◽  
Microtubule Organization ◽  
Atomistic Modelling

ABSTRACTHigh levels of the cold shock protein Y-box-binding protein-1, YB-1, are tightly correlated with increased cell proliferation and cancer progression. However, the precise mechanism by which YB-1 regulates proliferation is unknown. Here, we found that YB-1 depletion in several cell lines resulted in cytokinesis failure, multinucleation and an increase in G1 transit time. Rescue experiments indicated that YB-1 was required for completion of cytokinesis. Using confocal imaging of cells undergoing cytokinesis both in vitro and in zebrafish embryos, we found that YB-1 was critical for microtubule organization during cytokinesis. Using mass spectrometry we identified multiple novel phosphorylation sites on YB-1. We show that phosphorylation of YB-1 at multiple serine residues was essential for its function during cytokinesis. Using atomistic modelling we show how multiple phosphorylations alter YB-1 conformation, allowing it to interact with protein partners. Our results establish phosphorylated YB-1 as a critical regulator of cytokinesis, defining for the first time precisely how YB-1 regulates cell division.SUMMARYY-box-binding protein-1, YB-1, is essential for cell division, but it is not clear how it functions. Using live imaging and confocal microscopy we show that YB-1 functions only in the last step of division, specifically being required to initiate cytokinesis.

scholarly journals A Trypanosoma brucei orphan kinesin employs a convergent microtubule organization strategy to complete cytokinesis

2021 ◽  
Author(s):  
Thomas E Sladewski ◽  
Paul C Campbell ◽  
Neil Billington ◽  
Alexandra D'Ordine ◽  
Christopher L de Graffenried
Keyword(s):  
Trypanosoma Brucei ◽  
Biophysical Properties ◽  
Microtubule Organization ◽  
Division Plane ◽  
Mechanistic Insight ◽  
Organization Strategy ◽  
Cytoskeletal Elements ◽  
Order Structures ◽  
Insight Into

Many single-celled eukaryotes have complex cell morphologies defined by cytoskeletal elements comprising microtubules arranged into higher-order structures. Trypanosoma brucei (T. brucei) cell polarity is mediated by a parallel array of microtubules that underlie the plasma membrane and define the auger-like shape of the parasite. The subpellicular array must be partitioned and segregated using a microtubule-based mechanism during cell division. We previously identified an orphan kinesin, KLIF, that localizes to the division plane and is essential for the completion of cytokinesis. To gain mechanistic insight into how this novel kinesin functions to complete cleavage furrow ingression, we characterized the biophysical properties of the KLIF motor domain in vitro. We found that KLIF is a non-processive dimeric kinesin that dynamically crosslinks microtubules. Microtubules crosslinked in an antiparallel orientation are translocated relative to one another by KLIF, while microtubules crosslinked parallel to one another remain static, resulting in the formation of organized parallel bundles. In addition, we found that KLIF stabilizes the alignment of microtubule plus ends. These features provide a mechanistic understanding for how KLIF functions to form a new pole of aligned microtubule plus ends that defines the shape of the new posterior, which is a unique requirement for the completion of cytokinesis in T. brucei.

scholarly journals Proper division plane orientation and mitotic progression together allow normal growth of maize

2017 ◽  
Vol 114 (10) ◽  
pp. 2759-2764 ◽  
Author(s):  
Pablo Martinez ◽  
Anding Luo ◽  
Anne Sylvester ◽  
Carolyn G. Rasmussen
Keyword(s):  
Cell Cycle ◽  
Cell Biology ◽  
Cell Cycle Progression ◽  
Normal Growth ◽  
Mitotic Progression ◽  
Wild Type ◽  
Cycle Progression ◽  
Division Plane ◽  
Plane Orientation ◽  
Division Plane Orientation

How growth, microtubule dynamics, and cell-cycle progression are coordinated is one of the unsolved mysteries of cell biology. A maize mutant,tangled1, with known defects in growth and proper division plane orientation, and a recently characterized cell-cycle delay identified by time-lapse imaging, was used to clarify the relationship between growth, cell cycle, and proper division plane orientation. Thetangled1mutant was fully rescued by introduction of cortical division site localized TANGLED1-YFP. A CYCLIN1B destruction box was fused to TANGLED1-YFP to generate a line that mostly rescued the division plane defect but still showed cell-cycle delays when expressed in thetangled1mutant. Although an intermediate growth phenotype between wild-type and thetangled1mutant was expected, these partially rescued plants grew as well as wild-type siblings, indicating that mitotic progression delays alone do not alter overall growth. These data indicate that division plane orientation, together with proper cell-cycle progression, is critical for plant growth.

scholarly journals Fission Yeast mto2p Regulates Microtubule Nucleation by the Centrosomin-related Protein mto1p

2005 ◽  
Vol 16 (6) ◽  
pp. 3040-3051 ◽  
Author(s):  
Itaru Samejima ◽  
Paula C. C. Lourenço ◽  
Hilary A. Snaith ◽  
Kenneth E. Sawin
Keyword(s):  
Fission Yeast ◽  
Insertional Mutagenesis ◽  
Spindle Pole ◽  
Related Protein ◽  
Microtubule Nucleation ◽  
Microtubule Organization ◽  
Cytoplasmic Microtubule ◽  
Division Site ◽  
Cell Extracts

From an insertional mutagenesis screen, we isolated a novel gene, mto2+, involved in microtubule organization in fission yeast. mto2Δ strains are viable but exhibit defects in interphase microtubule nucleation and in formation of the postanaphase microtubule array at the end of mitosis. The mto2Δ defects represent a subset of the defects displayed by cells deleted for mto1+ (also known as mod20+ and mbo1+), a centrosomin-related protein required to recruit the γ-tubulin complex to cytoplasmic microtubule-organizing centers (MTOCs). We show that mto2p colocalizes with mto1p at MTOCs throughout the cell cycle and that mto1p and mto2p coimmunoprecipitate from cytoplasmic extracts. In vitro studies suggest that mto2p binds directly to mto1p. In mto2Δ mutants, although some aspects of mto1p localization are perturbed, mto1p can still localize to spindle pole bodies and the cell division site and to “satellite” particles on interphase microtubules. In mto1Δ mutants, localization of mto2p to all of these MTOCs is strongly reduced or absent. We also find that in mto2Δ mutants, cytoplasmic forms of the γ-tubulin complex are mislocalized, and the γ-tubulin complex no longer coimmunoprecipitates with mto1p from cell extracts. These experiments establish mto2p as a major regulator of mto1p-mediated microtubule nucleation by the γ-tubulin complex.

scholarly journals An overview of plant division-plane orientation

2018 ◽  
Vol 219 (2) ◽  
pp. 505-512 ◽  
Author(s):  
Carolyn G. Rasmussen ◽  
Marschal Bellinger
Keyword(s):  
Division Plane ◽  
Plane Orientation ◽  
Division Plane Orientation
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