scholarly journals A specific basal body linker protein provides the connection function for basal body inheritance in trypanosomes

2021 ◽  
Vol 118 (8) ◽  
pp. e2014040118
Author(s):  
De-Hua Lai ◽  
Flavia Moreira-Leite ◽  
Zhi-Shen Xu ◽  
Jiong Yang ◽  
Keith Gull
Keyword(s):  
Basal Body ◽  
Mammalian Cells ◽  
De Novo ◽  
Coiled Coil ◽  
Centriole Duplication ◽  
Cytoskeletal Component ◽  
Dividing Cells ◽  
Orthogonal Orientation ◽  
And Function ◽  
Additional Role

Centrioles and basal bodies (CBBs) are found in physically linked pairs, and in mammalian cells intercentriole connections (G1–G2 tether and S–M linker) regulate centriole duplication and function. In trypanosomes BBs are not associated with the spindle and function in flagellum/cilia nucleation with an additional role in mitochondrial genome (kinetoplast DNA [kDNA]) segregation. Here, we describe BBLP, a BB/pro-BB (pBB) linker protein in Trypanosoma brucei predicted to be a large coiled-coil protein conserved in the kinetoplastida. Colocalization with the centriole marker SAS6 showed that BBLP localizes between the BB/pBB pair, throughout the cell cycle, with a stronger signal in the old flagellum BB/pBB pair. Importantly, RNA interference (RNAi) depletion of BBLP leads to a conspicuous splitting of the BB/pBB pair associated only with the new flagellum. BBLP RNAi is lethal in the bloodstream form of the parasite and perturbs mitochondrial kDNA inheritance. Immunogold labeling confirmed that BBLP is localized to a cytoskeletal component of the BB/pBB linker, and tagged protein induction showed that BBLP is incorporated de novo in both new and old flagella BB pairs of dividing cells. We show that the two aspects of CBB disengagement—loss of orthogonal orientation and ability to separate and move apart—are consistent but separable events in evolutionarily diverse cells and we provide a unifying model explaining centriole/BB linkage differences between such cells.

scholarly journals Drosophila chibby is required for basal body formation and ciliogenesis but not for Wg signaling

2012 ◽  
Vol 197 (2) ◽  
pp. 313-325 ◽  
Author(s):  
Camille Enjolras ◽  
Joëlle Thomas ◽  
Brigitte Chhin ◽  
Elisabeth Cortier ◽  
Jean-Luc Duteyrat ◽  
...  
Keyword(s):  
Wnt Signaling ◽  
Basal Body ◽  
Coiled Coil ◽  
Cell Types ◽  
Sensory Transduction ◽  
Basal Bodies ◽  
Neuronal Cilia ◽  
Complex Process ◽  
Specific Proteins ◽  
And Function

Centriole-to–basal body conversion, a complex process essential for ciliogenesis, involves the progressive addition of specific proteins to centrioles. CHIBBY (CBY) is a coiled-coil domain protein first described as interacting with β-catenin and involved in Wg-Int (WNT) signaling. We found that, in Drosophila melanogaster, CBY was exclusively expressed in cells that require functional basal bodies, i.e., sensory neurons and male germ cells. CBY was associated with the basal body transition zone (TZ) in these two cell types. Inactivation of cby led to defects in sensory transduction and in spermatogenesis. Loss of CBY resulted in altered ciliary trafficking into neuronal cilia, irregular deposition of proteins on spermatocyte basal bodies, and, consequently, distorted axonemal assembly. Importantly, cby1/1 flies did not show Wingless signaling defects. Hence, CBY is essential for normal basal body structure and function in Drosophila, potentially through effects on the TZ. The function of CBY in WNT signaling in vertebrates has either been acquired during vertebrate evolution or lost in Drosophila.

scholarly journals The Golgin Protein RUD3 Regulates Fusarium graminearum Growth and Virulence

2021 ◽  
Vol 87 (6) ◽  
Author(s):  
Chenyu Wang ◽  
Yao Wang ◽  
Liyuan Zhang ◽  
Ziyi Yin ◽  
Yuancun Liang ◽  
...  
Keyword(s):  
Fusarium Graminearum ◽  
Vegetative Growth ◽  
Mammalian Cells ◽  
Cellular Localization ◽  
Pathogenic Fungus ◽  
Coiled Coil ◽  
Effective Control ◽  
Content Type ◽  
Ascospore Discharge ◽  
And Function

ABSTRACT Golgins are coiled-coil proteins that play prominent roles in maintaining the structure and function of the Golgi complex. However, the role of golgin proteins in phytopathogenic fungi remains poorly understood. In this study, we functionally characterized the Fusarium graminearum golgin protein RUD3, a homolog of ScRUD3/GMAP-210 in Saccharomyces cerevisiae and mammalian cells. Cellular localization observation revealed that RUD3 is located in the cis-Golgi. Deletion of RUD3 caused defects in vegetative growth, ascospore discharge, deoxynivalenol (DON) production, and virulence. Moreover, the Δrud3 mutant showed reduced expression of tri genes and impairment of the formation of toxisomes, both of which play essential roles in DON biosynthesis. We further used green fluorescent protein (GFP)-tagged SNARE protein SEC22 (SEC22-GFP) as a tool to study the transport between the endoplasmic reticulum (ER) and Golgi and observed that SEC22-GFP was retained in the cis-Golgi in the Δrud3 mutant. RUD3 contains the coiled coil (CC), GRAB-associated 2 (GA2), GRIP-related Arf binding (GRAB), and GRAB-associated 1 (GA1) domains, which except for GA1, are indispensable for normal localization and function of RUD3, whereas only CC is essential for normal RUD3-RUD3 interaction. Together, these results demonstrate how the golgin protein RUD3 mediates retrograde trafficking in the ER-to-Golgi pathway and is necessary for growth, ascospore discharge, DON biosynthesis, and pathogenicity in F. graminearum. IMPORTANCE Fusarium head blight (FHB) caused by the fungal pathogen Fusarium graminearum is an economically important disease of wheat and other small grain cereal crops worldwide, and limited effective control strategies are available. A better understanding of the regulation mechanisms of F. graminearum development, deoxynivalenol (DON) biosynthesis, and pathogenicity is therefore important for the development of effective control management of this disease. Golgins are attached via their extreme carboxy terminus to the Golgi membrane and are involved in vesicle trafficking and organelle maintenance in eukaryotic cells. In this study, we systematically characterized a highly conserved Golgin protein, RUD3, and found that it is required for vegetative growth, ascospore discharge, DON production, and pathogenicity in F. graminearum. Our findings provide a comprehensive characterization of the golgin family protein RUD3 in plant-pathogenic fungus, which could help to identify a new potential target for effective control of this devastating disease.

scholarly journals Segregation and activation of myosin IIB creates a rear in migrating cells

2008 ◽  
Vol 183 (3) ◽  
pp. 543-554 ◽  
Author(s):  
Miguel Vicente-Manzanares ◽  
Margaret A. Koach ◽  
Leanna Whitmore ◽  
Marcelo L. Lamers ◽  
Alan F. Horwitz
Keyword(s):  
Self Assembly ◽  
De Novo ◽  
Coiled Coil ◽  
Myosin Isoforms ◽  
C Terminus ◽  
Filament Bundles ◽  
A Cell ◽  
Myosin Iia ◽  
And Function ◽  
Migrating Cells

We have found that MLC-dependent activation of myosin IIB in migrating cells is required to form an extended rear, which coincides with increased directional migration. Activated myosin IIB localizes prominently at the cell rear and produces large, stable actin filament bundles and adhesions, which locally inhibit protrusion and define the morphology of the tail. Myosin IIA forms de novo filaments away from the myosin IIB–enriched center and back to form regions that support protrusion. The positioning and dynamics of myosin IIA and IIB depend on the self-assembly regions in their coiled-coil C terminus. COS7 and B16 melanoma cells lack myosin IIA and IIB, respectively; and show isoform-specific front-back polarity in migrating cells. These studies demonstrate the role of MLC activation and myosin isoforms in creating a cell rear, the segregation of isoforms during filament assembly and their differential effects on adhesion and protrusion, and a key role for the noncontractile region of the isoforms in determining their localization and function.

scholarly journals Microtubule-bundling protein Spef1 enables mammalian ciliary central apparatus formation

2018 ◽  
Vol 11 (1) ◽  
pp. 67-77 ◽  
Author(s):  
Jianqun Zheng ◽  
Hao Liu ◽  
Lei Zhu ◽  
Yawen Chen ◽  
Huijie Zhao ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Coiled Coil ◽  
Cell Movement ◽  
Ependymal Cells ◽  
Coiled Coil Region ◽  
Evolutionarily Conserved ◽  
Flow Through ◽  
Ependymal Cilia ◽  
And Function ◽  
Signal Transductions

Abstract Cilia are cellular protrusions containing nine microtubule (MT) doublets and function to propel cell movement or extracellular liquid flow through beating or sense environmental stimuli through signal transductions. Cilia require the central pair (CP) apparatus, consisting of two CP MTs covered with projections of CP proteins, for planar strokes. How the CP MTs of such ‘9 + 2’ cilia are constructed, however, remains unknown. Here we identify Spef1, an evolutionarily conserved microtubule-bundling protein, as a core CP MT regulator in mammalian cilia. Spef1 was selectively expressed in mammalian cells with 9 + 2 cilia and specifically localized along the CP. Its depletion in multiciliated mouse ependymal cells by RNAi completely abolished the CP MTs and markedly attenuated ciliary localizations of CP proteins such as Hydin and Spag6, resulting in rotational beat of the ependymal cilia. Spef1, which binds to MTs through its N-terminal calponin-homologous domain, formed homodimers through its C-terminal coiled coil region to bundle and stabilize MTs. Disruption of either the MT-binding or the dimerization activity abolished the ability of exogenous Spef1 to restore the structure and functions of the CP apparatus. We propose that Spef1 bundles and stabilizes central MTs to enable the assembly and functions of the CP apparatus.

scholarly journals Molecular basis of the STIL coiled coil oligomerization explains its requirement for de-novo formation of centrosomes in mammalian cells

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Ahuvit David ◽  
Hadar Amartely ◽  
Noa Rabinowicz ◽  
Mai Shamir ◽  
Assaf Friedler ◽  
...  
Keyword(s):  
Molecular Basis ◽  
Mammalian Cells ◽  
De Novo ◽  
Coiled Coil

De Novo Design, Synthesis, and Function of Semiartificial Myoglobin Conjugated with Coiled-Coil Two-α-Helix Peptides

2004 ◽  
Vol 10 (15) ◽  
pp. 3717-3726 ◽  
Author(s):  
Seiji Sakamoto ◽  
Atsushi Ito ◽  
Kazuaki Kudo ◽  
Susumu Yoshikawa
Keyword(s):  
De Novo ◽  
Coiled Coil ◽  
De Novo Design ◽  
Design Synthesis ◽  
Α Helix ◽  
And Function

SFI1 and centrin form a distal end complex critical for proper centriole architecture and ciliogenesis

2021 ◽  
Author(s):  
Imène B. Bouhlel ◽  
Marine. H. Laporte ◽  
Eloïse Bertiaux ◽  
Alexia Giroud ◽  
Susanne Borgers ◽  
...  
Keyword(s):  
Basal Body ◽  
Spindle Pole Body ◽  
Super Resolution ◽  
Spindle Pole ◽  
Specific Loss ◽  
Centriole Duplication ◽  
Pole Body ◽  
Core Elements ◽  
Bona Fide ◽  
And Function

AbstractOver the course of evolution, the function of the centrosome has been conserved in most eukaryotes, but its core architecture has evolved differently in some clades, as illustrated by the presence of centrioles in humans and a spindle pole body in yeast (SPB). Consistently, the composition of these two core elements has diverged greatly, with the exception of centrin, a protein known to form a complex with Sfi1 in yeast to structurally initiate SPB duplication. Even though SFI1 has been localized to human centrosomes, whether this complex exists at centrioles and whether its function has been conserved is still unclear. Here, using conventional fluorescence and super-resolution microscopies, we demonstrate that human SFI1 is a bona fide centriolar protein localizing to the very distal end of the centriole, where it associates with a pool of distal centrin. We also found that both proteins are recruited early during procentriole assembly and that depletion of SFI1 results in the specific loss of the distal pool of centrin, without altering centriole duplication in human cells, in contrast to its function for SPB. Instead, we found that SFI1/centrin complexes are essential for correct centriolar architecture as well as for ciliogenesis. We propose that SFI1/centrin complexes may guide centriole growth to ensure centriole integrity and function as a basal body.

scholarly journals A centriolar FGR1 oncogene partner-like protein required for paraflagellar rod assembly, but not axoneme assembly in African trypanosomes

Open Biology ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 170218 ◽  
Author(s):  
Jane Harmer ◽  
Katie Towers ◽  
Max Addison ◽  
Sue Vaughan ◽  
Michael L. Ginger ◽  
...  
Keyword(s):  
Basal Body ◽  
Mitotic Spindle ◽  
Cell Biology ◽  
Mammalian Cells ◽  
Molecular Level ◽  
African Trypanosomes ◽  
Spindle Poles ◽  
Microtubule Organizing Centres ◽  
Polar Spindle ◽  
And Function

Proteins of the FGR1 oncogene partner (or FOP) family are found at microtubule organizing centres (MTOCs) including, in flagellate eukaryotes, the centriole or flagellar basal body from which the axoneme extends. We report conservation of FOP family proteins, Tb FOPL and Tb OFD1, in the evolutionarily divergent sleeping sickness parasite Trypanosoma brucei , showing (in contrast with mammalian cells, where FOP is essential for flagellum assembly) depletion of a trypanosome FOP homologue, Tb FOPL, affects neither axoneme nor flagellum elongation. Instead, Tb FOPL depletion causes catastrophic failure in assembly of a lineage-specific, extra-axonemal structure, the paraflagellar rod (PFR). That depletion of centriolar Tb FOPL causes failure in PFR assembly is surprising because PFR nucleation commences approximately 2 µm distal from the basal body. When over-expressed with a C-terminal myc-epitope, Tb FOPL was also observed at mitotic spindle poles. Little is known about bi-polar spindle assembly during closed trypanosome mitosis, but indication of a possible additional MTOC function for Tb FOPL parallels MTOC localization of FOP-like protein TONNEAU1 in acentriolar plants. More generally, our functional analysis of Tb FOPL emphasizes significant differences in evolutionary cell biology trajectories of FOP-family proteins. We discuss how at the molecular level FOP homologues may contribute to flagellum assembly and function in diverse flagellates.

TMCC3 localizes at the three-way junctions for the proper tubular network of the endoplasmic reticulum

2019 ◽  
Vol 476 (21) ◽  
pp. 3241-3260
Author(s):  
Sindhu Wisesa ◽  
Yasunori Yamamoto ◽  
Toshiaki Sakisaka
Keyword(s):  
Endoplasmic Reticulum ◽  
Membrane Proteins ◽  
Membrane Protein ◽  
Mammalian Cells ◽  
Coiled Coil ◽  
Transmembrane Domains ◽  
Domain Family ◽  
Coiled Coil Domain ◽  
U2os Cells ◽  
Er Membrane

The tubular network of the endoplasmic reticulum (ER) is formed by connecting ER tubules through three-way junctions. Two classes of the conserved ER membrane proteins, atlastins and lunapark, have been shown to reside at the three-way junctions so far and be involved in the generation and stabilization of the three-way junctions. In this study, we report TMCC3 (transmembrane and coiled-coil domain family 3), a member of the TEX28 family, as another ER membrane protein that resides at the three-way junctions in mammalian cells. When the TEX28 family members were transfected into U2OS cells, TMCC3 specifically localized at the three-way junctions in the peripheral ER. TMCC3 bound to atlastins through the C-terminal transmembrane domains. A TMCC3 mutant lacking the N-terminal coiled-coil domain abolished localization to the three-way junctions, suggesting that TMCC3 localized independently of binding to atlastins. TMCC3 knockdown caused a decrease in the number of three-way junctions and expansion of ER sheets, leading to a reduction of the tubular ER network in U2OS cells. The TMCC3 knockdown phenotype was partially rescued by the overexpression of atlastin-2, suggesting that TMCC3 knockdown would decrease the activity of atlastins. These results indicate that TMCC3 localizes at the three-way junctions for the proper tubular ER network.

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