scholarly journals Sas-4 proteins are required during basal body duplication in Paramecium

2011 ◽  
Vol 22 (7) ◽  
pp. 1035-1044 ◽  
Author(s):  
Delphine Gogendeau ◽  
Ilse Hurbain ◽  
Graca Raposo ◽  
Jean Cohen ◽  
France Koll ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Basal Body ◽  
Basal Bodies ◽  
Paramecium Tetraurelia ◽  
Animal Cells ◽  
Centriole Duplication ◽  
Specific Order ◽  
In Cells

Centrioles and basal bodies are structurally related organelles composed of nine microtubule (MT) triplets. Studies performed in Caenorhabditis elegans embryos have shown that centriole duplication takes place in sequential way, in which different proteins are recruited in a specific order to assemble a procentriole. ZYG-1 initiates centriole duplication by triggering the recruitment of a complex of SAS-5 and SAS-6, which then recruits the final player, SAS-4, to allow the incorporation of MT singlets. It is thought that a similar mechanism (that also involves additional proteins) is present in other animal cells, but it remains to be investigated whether the same players and their ascribed functions are conserved during basal body duplication in cells that exclusively contain basal bodies. To investigate this question, we have used the multiciliated protist Paramecium tetraurelia. Here we show that in the absence of PtSas4, two types of defects in basal body duplication can be identified. In the majority of cases, the germinative disk and cartwheel, the first structures assembled during duplication, are not detected. In addition, if daughter basal bodies were formed, they invariably had defects in MT recruitment. Our results suggest that PtSas4 has a broader function than its animal orthologues.

scholarly journals Genetic Evidence for Interaction between η- and β-Tubulins

2004 ◽  
Vol 3 (1) ◽  
pp. 212-220 ◽  
Author(s):  
F. Ruiz ◽  
P. Dupuis-Williams ◽  
C. Klotz ◽  
F. Forquignon ◽  
M. Bergdoll ◽  
...  
Keyword(s):  
Basal Body ◽  
Mutant Phenotype ◽  
Basal Bodies ◽  
Paramecium Tetraurelia ◽  
Nonpermissive Temperature ◽  
Genetic Approach ◽  
Gene Coding ◽  
End Capping ◽  
Extragenic Suppressors ◽  
Β Tubulin

ABSTRACT The thermosensitive allelic mutations sm19-1 and sm19-2 of Paramecium tetraurelia cause defective basal body duplication: growth at the nonpermissive temperature yields smaller and smaller cells with fewer and fewer basal bodies. Complementation cloning of the SM19 gene identified a new tubulin, eta-tubulin, showing low homology with each of the other five tubulins, α to ε, characterized in P. tetraurelia. In order to analyze η-tubulin functions, we used a genetic approach to identify interacting molecules. Among a series of extragenic suppressors of the sm19-1 mutation, the su3-1 mutation was characterized as an E288K substitution in the β-PT2 gene coding for a β-tubulin, while the mutation nocr 1 conferring nocodazole resistance and localized in another β-tubulin gene, β-PT3, was shown to enhance the mutant phenotype. The interaction between η-tubulin and microtubules, revealed by genetic data, is supported by two further types of evidence: first, the mutant phenotype is rescued by taxol, which stabilizes microtubules; second, molecular modeling suggests that η-tubulin, like γ- and δ-tubulins, might be a microtubule minus-end capping molecule. The likely function of η-tubulin as part of a complex specifically involved in basal body biogenesis is discussed.

scholarly journals Cep120 is asymmetrically localized to the daughter centriole and is essential for centriole assembly

2010 ◽  
Vol 191 (2) ◽  
pp. 331-346 ◽  
Author(s):  
Moe R. Mahjoub ◽  
Zhigang Xie ◽  
Tim Stearns
Keyword(s):  
Basal Bodies ◽  
Animal Cells ◽  
Tracheal Epithelial Cells ◽  
Centriole Duplication ◽  
Photobleaching Recovery ◽  
Mother And Daughter ◽  
Tracheal Epithelial ◽  
Centriole Assembly ◽  
And Function ◽  
Daughter Centriole

Centrioles form the core of the centrosome in animal cells and function as basal bodies that nucleate and anchor cilia at the plasma membrane. In this paper, we report that Cep120 (Ccdc100), a protein previously shown to be involved in maintaining the neural progenitor pool in mouse brain, is associated with centriole structure and function. Cep120 is up-regulated sevenfold during differentiation of mouse tracheal epithelial cells (MTECs) and localizes to basal bodies. Cep120 localizes preferentially to the daughter centriole in cycling cells, and this asymmetry between mother and daughter centrioles is relieved coincident with new centriole assembly. Photobleaching recovery analysis identifies two pools of Cep120, differing in their halftime at the centriole. We find that Cep120 is required for centriole duplication in cycling cells, centriole amplification in MTECs, and centriole overduplication in S phase–arrested cells. We propose that Cep120 is required for centriole assembly and that the observed defect in neuronal migration might derive from a defect in this process.

The formation of basal body domains in the membrane skeleton of Tetrahymena

Development ◽  
1990 ◽  
Vol 109 (4) ◽  
pp. 935-942 ◽  
Author(s):  
N.E. Williams ◽  
J.E. Honts ◽  
J. Kaczanowska
Keyword(s):  
Cell Cycle ◽  
Basal Body ◽  
Membrane Skeleton ◽  
Basal Bodies ◽  
Molecular Events ◽  
Similarities And Differences ◽  
The Individual ◽  
In Cells

Differentiated regions within the membrane skeleton are described around basal bodies in the ciliary rows of Tetrahymena. These domains, approximately 1 micron in diameter, are characterized by a relatively dense ultrastructure, the presence of a family of proteins called K antigens (Mr 39–44 × 10(3)) that are recognized by mAb 424A8, and the apparent exclusion of major membrane skeleton proteins that are present in most other regions of the cell (Mr 135, 125 × 10(3]. Mature basal body domains are asymmetric, reflecting the polarity of the cell as a whole. A similar differentiation of the membrane skeleton occurs in the oral apparatus, except here the K antigens surround four clusters of basal bodies (from which this cell takes its name) rather than the individual basal bodies. The development of new basal body domains in the cell cycle is described, with similarities and differences noted between somatic and oral regions of the cell. It is concluded that the capacity of this cell for precise topographic regulation of molecular events in the membrane skeleton makes it a useful model for the study of cortical differentiation in cells generally.

Domain-specific changes of ciliary striated rootlets during the cell cycle in the hypotrich ciliate Paraurostyla weissei

1990 ◽  
Vol 96 (4) ◽  
pp. 617-630
Author(s):  
MARIA JERKA-DZIADOSZ
Keyword(s):  
Cell Cycle ◽  
Basal Body ◽  
Polyclonal Antibody ◽  
Paramecium Tetraurelia ◽  
Site Specific ◽  
Domain Specific ◽  
Interphase Cells ◽  
Cr System ◽  
The Right ◽  
In Cells

The dynamics of striated ciliary rootlets (cr) during development of ciliary structures in cells of the hypotrich ciliate Paraurostyla weissei was studied by immunostaining with polyclonal antibody raised against isolated cr of Paramecium tetraurelia. Wildtype cells and two mutants: mlm/pl showing multiple left marginal cirri and mlm/pl showing in addition a certain degree of pattern lability were used to study the boundaries of particular cortex domains. In interphase cells, cr are attached to all left marginal and caudal cirri and to only the posterior third of the right marginal cirri, cr appear in all nonoral primordia during the first wave of basal body proliferation. After nucleation and early elongation of cr, some cr undergo site-specific regression or stabilization. The spatial deployment of these different modes of development corresponds to specific cortical domains. In mlm/pl mutants, where specific cortical domains are broadened, changes in the cr system are characteristic for a given domain, regardless of its broadening, but boundaries between adjacent domains are weakened.

scholarly journals The centriole duplication cycle

2014 ◽  
Vol 369 (1650) ◽  
pp. 20130460 ◽  
Author(s):  
Elif Nur Fırat-Karalar ◽  
Tim Stearns
Keyword(s):  
Cell Cycle ◽  
Cell Polarization ◽  
Brain Diseases ◽  
Basal Bodies ◽  
Animal Cells ◽  
Centriole Duplication ◽  
Pericentriolar Material ◽  
Cilia And Flagella ◽  
Duplication Cycle ◽  
Lower Plant

Centrosomes are the main microtubule-organizing centre of animal cells and are important for many critical cellular and developmental processes from cell polarization to cell division. At the core of the centrosome are centrioles, which recruit pericentriolar material to form the centrosome and act as basal bodies to nucleate formation of cilia and flagella. Defects in centriole structure, function and number are associated with a variety of human diseases, including cancer, brain diseases and ciliopathies. In this review, we discuss recent advances in our understanding of how new centrioles are assembled and how centriole number is controlled. We propose a general model for centriole duplication control in which cooperative binding of duplication factors defines a centriole ‘origin of duplication’ that initiates duplication, and passage through mitosis effects changes that license the centriole for a new round of duplication in the next cell cycle. We also focus on variations on the general theme in which many centrioles are created in a single cell cycle, including the specialized structures associated with these variations, the deuterosome in animal cells and the blepharoplast in lower plant cells.

Ciliary coordination in newt lung cells requires microtubule-based linkages between basal bodies: A correlative light and EM study

1992 ◽  
Vol 50 (1) ◽  
pp. 570-571
Author(s):  
Robert Hard ◽  
Gerald Rupp ◽  
Matthew L. Withiam-Leitch ◽  
Lisa Cardamone
Keyword(s):  
Basal Body ◽  
Untreated Control ◽  
Beat Frequency ◽  
Primary Cultures ◽  
Living Cells ◽  
Power Stroke ◽  
Ultrastructural Changes ◽  
Lung Cells ◽  
Basal Bodies ◽  
Ciliated Cells

In a coordinated field of beating cilia, the direction of the power stroke is correlated with the orientation of basal body appendages, called basal feet. In newt lung ciliated cells, adjacent basal feet are interconnected by cold-stable microtubules (basal MTs). In the present study, we investigate the hypothesis that these basal MTs stabilize ciliary distribution and alignment. To accomplish this, newt lung primary cultures were treated with the microtubule disrupting agent, Colcemid. In newt lung cultures, cilia normally disperse in a characteristic fashion as the mucociliary epithelium migrates from the tissue explant. Four arbitrary, but progressive stages of dispersion were defined and used to monitor this redistribution process. Ciliaiy beat frequency, coordination, and dispersion were assessed for 91 hrs in untreated (control) and treated cultures. When compared to controls, cilia dispersed more rapidly and ciliary coordination decreased markedly in cultures treated with Colcemid (2 mM). Correlative LM/EM was used to assess whether these effects of Colcemid were coupled to ultrastructural changes. Living cells were defined as having coordinated or uncoordinated cilia and then were processed for transmission EM.

scholarly journals Functional Redundancy of the B9 Proteins and Nephrocystins in Caenorhabditis elegans Ciliogenesis

2008 ◽  
Vol 19 (5) ◽  
pp. 2154-2168 ◽  
Author(s):  
Corey L. Williams ◽  
Marlene E. Winkelbauer ◽  
Jenny C. Schafer ◽  
Edward J. Michaud ◽  
Bradley K. Yoder
Keyword(s):  
Caenorhabditis Elegans ◽  
Joubert Syndrome ◽  
Cystic Kidney ◽  
Basal Bodies ◽  
The Novel ◽  
C Elegans ◽  
Human Genes ◽  
Cilia Formation ◽  
Strong Candidate ◽  
Candidate Loci

Meckel-Gruber syndrome (MKS), nephronophthisis (NPHP), and Joubert syndrome (JBTS) are a group of heterogeneous cystic kidney disorders with partially overlapping loci. Many of the proteins associated with these diseases interact and localize to cilia and/or basal bodies. One of these proteins is MKS1, which is disrupted in some MKS patients and contains a B9 motif of unknown function that is found in two other mammalian proteins, B9D2 and B9D1. Caenorhabditis elegans also has three B9 proteins: XBX-7 (MKS1), TZA-1 (B9D2), and TZA-2 (B9D1). Herein, we report that the C. elegans B9 proteins form a complex that localizes to the base of cilia. Mutations in the B9 genes do not overtly affect cilia formation unless they are in combination with a mutation in nph-1 or nph-4, the homologues of human genes (NPHP1 and NPHP4, respectively) that are mutated in some NPHP patients. Our data indicate that the B9 proteins function redundantly with the nephrocystins to regulate the formation and/or maintenance of cilia and dendrites in the amphid and phasmid ciliated sensory neurons. Together, these data suggest that the human homologues of the novel B9 genes B9D2 and B9D1 will be strong candidate loci for pathologies in human MKS, NPHP, and JBTS.

scholarly journals Drosophila Ana2 is a conserved centriole duplication factor

2010 ◽  
Vol 188 (3) ◽  
pp. 313-323 ◽  
Author(s):  
Naomi R. Stevens ◽  
Jeroen Dobbelaere ◽  
Kathrin Brunk ◽  
Anna Franz ◽  
Jordan W. Raff
Keyword(s):  
Drosophila Melanogaster ◽  
Caenorhabditis Elegans ◽  
De Novo ◽  
Protein Family ◽  
Centriole Duplication

In Caenorhabditis elegans, five proteins are required for centriole duplication: SPD-2, ZYG-1, SAS-5, SAS-6, and SAS-4. Functional orthologues of all but SAS-5 have been found in other species. In Drosophila melanogaster and humans, Sak/Plk4, DSas-6/hSas-6, and DSas-4/CPAP—orthologues of ZYG-1, SAS-6, and SAS-4, respectively—are required for centriole duplication. Strikingly, all three fly proteins can induce the de novo formation of centriole-like structures when overexpressed in unfertilized eggs. Here, we find that of eight candidate duplication factors identified in cultured fly cells, only two, Ana2 and Asterless (Asl), share this ability. Asl is now known to be essential for centriole duplication in flies, but no equivalent protein has been found in worms. We show that Ana2 is the likely functional orthologue of SAS-5 and that it is also related to the vertebrate STIL/SIL protein family that has been linked to microcephaly in humans. We propose that members of the SAS-5/Ana2/STIL family of proteins are key conserved components of the centriole duplication machinery.

Structural Analysis of Basal Bodies of The Isolated Oral Apparatus of Tetrahymena Pyriformis

1970 ◽  
Vol 6 (3) ◽  
pp. 679-700
Author(s):  
J. WOLFE
Keyword(s):  
Structural Analysis ◽  
Cell Membrane ◽  
Basal Body ◽  
Structural Integrity ◽  
Tetrahymena Pyriformis ◽  
Basal Plate ◽  
Basal Bodies ◽  
The Third ◽  
Ionic Detergent

The oral apparatus of Tetrahymena pyriformis was isolated using a non-ionic detergent to disrupt the cell membrane. The mouth consists largely of basal bodies and microfilaments. Each basal body is attached to the mouth by a basal plate which is integrated into the meshwork of microfilaments that confers upon the oral apparatus its structural integrity. Each basal body is composed of 9 triplet microtubules. Two of the 3 tubules, subfibres ‘A’ and ‘B’ are composed of filamentous rows of globules with a spacing of 4.5nm. The third tubule, subfibre ‘C’, is only one-third the length of the basal body.

scholarly journals The Caenorhabditis elegans nephrocystins act as global modifiers of cilium structure

2008 ◽  
Vol 180 (5) ◽  
pp. 973-988 ◽  
Author(s):  
Andrew R. Jauregui ◽  
Ken C.Q. Nguyen ◽  
David H. Hall ◽  
Maureen M. Barr
Keyword(s):  
Caenorhabditis Elegans ◽  
Intraflagellar Transport ◽  
Basal Bodies ◽  
Structural Components ◽  
Transition Zones ◽  
C Elegans ◽  
Cell Type Specific ◽  
Children And Young Adults ◽  
Stage Renal Disease ◽  
End Stage

Nephronophthisis (NPHP) is the most common genetic cause of end-stage renal disease in children and young adults. In Chlamydomonas reinhardtii, Caenorhabditis elegans, and mammals, the NPHP1 and NPHP4 gene products nephrocystin-1 and nephrocystin-4 localize to basal bodies or ciliary transition zones (TZs), but their function in this location remains unknown. We show here that loss of C. elegans NPHP-1 and NPHP-4 from TZs is tolerated in developing cilia but causes changes in localization of specific ciliary components and a broad range of subtle axonemal ultrastructural defects. In amphid channel cilia, nphp-4 mutations cause B tubule defects that further disrupt intraflagellar transport (IFT). We propose that NPHP-1 and NPHP-4 act globally at the TZ to regulate ciliary access of the IFT machinery, axonemal structural components, and signaling molecules, and that perturbing this balance results in cell type–specific phenotypes.

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