Epiplasmins and Epiplasm in Paramecium: The Building of a Submembraneous Cytoskeleton

Aubusson-Fleury, Anne; Bricheux, Geneviève; Damaj, Raghida; Lemullois, Michel; Coffe, Gérard; Donnadieu, Florence; Viguès, Bernard; Bouchard, Philippe

doi:10.1016/j.protis.2013.04.003

Cited by 22 publications

(29 citation statements)

References 46 publications

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“…All over the cell surface, basal bodies, organised as antero-posterior rows, are inserted in a submembranar cytoskeleton, the epiplasm, segmented in longitudinal files of ‘cortical units’, within which one or two basal bodies are anchored (Iftode et al, 1989; Aubusson-Fleury et al, 2013). During division, the assembly of new basal bodies generates an alternance of parental and new basal bodies along each row.…”

Section: Resultsmentioning

confidence: 99%

Centrin diversity and basal body patterning across evolution: new insights fromParamecium

et al. 2017

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First discovered in unicellular eukaryotes, centrins play crucial roles in basal body duplication and anchoring mechanisms. While the evolutionary status of the founding members of the family, Centrin2/Vfl2 and Centrin3/cdc31 has long been investigated, the evolutionary origin of other members of the family has received less attention. Using a phylogeny of ciliate centrins, we identify two other centrin families, the ciliary centrins and the centrins present in the contractile filaments (ICL centrins). In this paper, we carry on the functional analysis of still not well-known centrins, the ICL1e subfamily identified in Paramecium, and show their requirement for correct basal body anchoring through interactions with Centrin2 and Centrin3. Using Paramecium as well as a eukaryote-wide sampling of centrins from completely sequenced genomes, we revisited the evolutionary story of centrins. Their phylogeny shows that the centrins associated with the ciliate contractile filaments are widespread in eukaryotic lineages and could be as ancient as Centrin2 and Centrin3.

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Section: Resultsmentioning

confidence: 99%

Centrin diversity and basal body patterning across evolution: new insights fromParamecium

et al. 2017

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“…C. elegans and D. melanogaster ). Most single-celled ciliated organisms have the ZED tubulin module (Table S1) and have basal body appendages that are functionally analogous to those in vertebrates [29, 30]. Disruption of ZED tubulins in these organisms results in significant cytoskeletal defects, consistent with the ZED tubulins having a conserved role in basal body-cytoskeleton interactions [31, 32].…”

Section: Discussionmentioning

confidence: 99%

Zeta-Tubulin Is a Member of a Conserved Tubulin Module and Is a Component of the Centriolar Basal Foot in Multiciliated Cells

et al. 2015

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SUMMARY There are six members of the tubulin superfamily in eukaryotes [1]. Alpha- and beta-tubulin form a heterodimer that polymerizes to form microtubules, and gamma-tubulin nucleates microtubules as a component of the gamma-tubulin ring complex. Alpha-, beta-, and gamma-tubulin are conserved in all eukaryotes. In contrast, delta- and epsilon-tubulin are conserved in many, but not all, eukaryotes and are associated with centrioles, although their molecular function is unclear [2–7]. Zeta-tubulin is the sixth and final member of the tubulin superfamily, and is largely uncharacterized. We find that zeta-, epsilon-, and delta-tubulin form an evolutionarily co-conserved module, the ZED module, that has been lost at several junctions in eukaryotic evolution, and that zeta- and delta-tubulin are evolutionarily interchangeable. Humans lack zeta-tubulin, but have delta-tubulin. In Xenopus multiciliated cells, zeta-tubulin is a component of the basal foot, a centriolar appendage that connects centrioles to the apical cytoskeleton, and co-localizes there with epsilon-tubulin. Depletion of zeta-tubulin results in disorganization of centriole distribution and polarity in multiciliated cells. In contrast with multiciliated cells, zeta-tubulin in cycling cells does not localize to centrioles and is associated with the TRiC/CCT cytoplasmic chaperone complex. We conclude that zeta-tubulin facilitates interactions between the centrioles and the apical cytoskeleton as a component of the basal foot in differentiated cells, and propose that the ZED tubulins are important for centriole functionalization and orientation of centrioles with respect to cellular polarity axes.

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“…In Paramecium tetraurelia cells, surface pattern formation depends on protein phosphorylation processes (Keryer et al, ; Sperling et al, ). Another factor is the self‐assembly of epiplasmins (Aubusson‐Fleury et al, ). Alveolins, proteins with charged repeat motifs, appear relevant for regular surface pattern formation since knock‐down entails disorganised cortical pattern in misshapen cells, as demonstrated with Tetrahymena thermophila (El‐Haddad et al, ).…”

Section: Epigenetic Signalling Encystment and ‘Programmed Nuclear Dementioning

confidence: 99%

Signalling in ciliates: long- and short-range signals and molecular determinants for cellular dynamics

Plattner

2015

Biol Rev

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In ciliates, unicellular representatives of the bikont branch of evolution, inter- and intracellular signalling pathways have been analysed mainly in Paramecium tetraurelia, Paramecium multimicronucleatum and Tetrahymena thermophila and in part also in Euplotes raikovi. Electrophysiology of ciliary activity in Paramecium spp. is a most successful example. Established signalling mechanisms include plasmalemmal ion channels, recently established intracellular Ca -release channels, as well as signalling by cyclic nucleotides and Ca . Ca -binding proteins (calmodulin, centrin) and Ca -activated enzymes (kinases, phosphatases) are involved. Many organelles are endowed with specific molecules cooperating in signalling for intracellular transport and targeted delivery. Among them are recently specified soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs), monomeric GTPases, H -ATPase/pump, actin, etc. Little specification is available for some key signal transducers including mechanosensitive Ca -channels, exocyst complexes and Ca -sensor proteins for vesicle-vesicle/membrane interactions. The existence of heterotrimeric G-proteins and of G-protein-coupled receptors is still under considerable debate. Serine/threonine kinases dominate by far over tyrosine kinases (some predicted by phosphoproteomic analyses). Besides short-range signalling, long-range signalling also exists, e.g. as firmly installed microtubular transport rails within epigenetically determined patterns, thus facilitating targeted vesicle delivery. By envisaging widely different phenomena of signalling and subcellular dynamics, it will be shown (i) that important pathways of signalling and cellular dynamics are established already in ciliates, (ii) that some mechanisms diverge from higher eukaryotes and (iii) that considerable uncertainties still exist about some essential aspects of signalling.

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Epiplasmins and Epiplasm in Paramecium: The Building of a Submembraneous Cytoskeleton

Cited by 22 publications

References 46 publications

Centrin diversity and basal body patterning across evolution: new insights fromParamecium

Centrin diversity and basal body patterning across evolution: new insights fromParamecium

Zeta-Tubulin Is a Member of a Conserved Tubulin Module and Is a Component of the Centriolar Basal Foot in Multiciliated Cells

Signalling in ciliates: long- and short-range signals and molecular determinants for cellular dynamics

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