Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 218
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Sci Rep ; 12(1): 21468, 2022 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-36509813

RESUMO

Primary cilia are sensory organelles essential for embryonic and postnatal development, and tissue homeostasis in adulthood. They are generated in a cell cycle-dependent manner and found on most cells of the body. Although cilia formation is intensively investigated virtually nothing is known about the transcriptional regulation of primary ciliation. We used here Odf2/Cenexin, encoding a protein of the mother centriole and the basal body that is mandatory for primary cilia formation, as the target gene for the identification of transcriptional activators. We identified a consensus binding site for Fox transcription factors (TFs) in its promoter region and focused here on the Fox family. We found transcriptional activation of Odf2 neither by FOXO TFs nor by the core TF for multiciliation, FOXJ1. However, we identified FOXA1 as a transcriptional activator of Odf2 by reporter gene assays and qRT-PCR, and showed by qWB that Foxa1 knockdown caused a decrease in ODF2 and CP110 proteins. We verified the binding sequence of FOXA1 in the Odf2 promoter by ChIP. Finally, we demonstrated that knockdown of FOXA1 affected primary cilia formation. We, thus, showed for the first time, that FOXA1 regulates primary ciliation by transcriptional activation of ciliary genes.


Assuntos
Cílios , Proteínas de Choque Térmico , Cílios/genética , Cílios/metabolismo , Proteínas de Choque Térmico/metabolismo , Centríolos/metabolismo , Corpos Basais/metabolismo , Regulação da Expressão Gênica
2.
Sci Rep ; 12(1): 19028, 2022 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-36347932

RESUMO

The Ciliary Adhesion (CA) complex forms in close association with the basal bodies of cilia during the early stages of ciliogenesis and is responsible for mediating complex interactions with the actin networks of multiciliated cells (MCCs). However, its precise localization with respect to basal body accessory structures and the interactions that lead to its establishment in MCCs are not well understood. Here, we studied the distribution of the CA proteins using super-resolution imaging and possible interactions with the microtubule network. The results of this study reveal that the apical CA complex forms at the distal end of the basal foot and depends on microtubules. Our data also raise the possibility that CAs may have additional roles in the regulation of the organization of the microtubule network of MCCs.


Assuntos
Corpos Basais , Cílios , Cílios/metabolismo , Corpos Basais/metabolismo , Microtúbulos/metabolismo , Actinas/metabolismo
3.
Mol Biol Cell ; 33(14): ar146, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36287828

RESUMO

Motile cilia beat with an asymmetric waveform consisting of a power stroke that generates a propulsive force and a recovery stroke that returns the cilium back to the start. Cilia are anchored to the cell cortex by basal bodies (BBs) that are directly coupled to the ciliary doublet microtubules (MTs). We find that, consistent with ciliary forces imposing on BBs, bending patterns in BB triplet MTs are responsive to ciliary beating. BB bending varies as environmental conditions change the ciliary waveform. Bending occurs where striated fibers (SFs) attach to BBs and mutants with short SFs that fail to connect to adjacent BBs exhibit abnormal BB bending, supporting a model in which SFs couple ciliary forces between BBs. Finally, loss of the BB stability protein Poc1, which helps interconnect BB triplet MTs, prevents the normal distributed BB and ciliary bending patterns. Collectively, BBs experience ciliary forces and manage mechanical coupling of these forces to their surrounding cellular architecture for normal ciliary beating.


Assuntos
Corpos Basais , Cílios , Corpos Basais/metabolismo , Cílios/metabolismo , Microtúbulos/metabolismo , Fenômenos Mecânicos
4.
Proc Natl Acad Sci U S A ; 119(40): e2204294119, 2022 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-36161893

RESUMO

The tripartite attachment complex (TAC) couples the segregation of the single unit mitochondrial DNA of trypanosomes with the basal body (BB) of the flagellum. Here, we studied the architecture of the exclusion zone filament (EZF) of the TAC, the only known component of which is p197, that connects the BB with the mitochondrial outer membrane (OM). We show that p197 has three domains that are all essential for mitochondrial DNA inheritance. The C terminus of p197 interacts with the mature and probasal body (pro-BB), whereas its N terminus binds to the peripheral OM protein TAC65. The large central region of p197 has a high α-helical content and likely acts as a flexible spacer. Ultrastructure expansion microscopy (U-ExM) of cell lines exclusively expressing p197 versions of different lengths that contain both N- and C-terminal epitope tags demonstrates that full-length p197 alone can bridge the ∼270-nm distance between the BB and the cytosolic face of the OM. Thus U-ExM allows the localization of distinct domains within the same molecules and suggests that p197 is the TAC subunit most proximal to the BB. In addition, U-ExM revealed that p197 acts as a spacer molecule, as two shorter versions of p197, with the repeat domain either removed or replaced by the central domain of the Trypanosoma cruzi p197 ortholog reduced the distance between the BB and the OM in proportion to their predicted molecular weight.


Assuntos
Replicação do DNA , DNA Mitocondrial , Genoma Mitocondrial , Membranas Mitocondriais , Proteínas de Protozoários , Trypanosoma brucei brucei , Corpos Basais/química , DNA Mitocondrial/genética , Epitopos/química , Flagelos/química , Membranas Mitocondriais/química , Proteínas de Protozoários/química , Trypanosoma brucei brucei/química , Trypanosoma brucei brucei/genética
5.
PLoS Genet ; 18(9): e1010154, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36074756

RESUMO

Centrosomal protein of 164 kDa (CEP164) is located at distal appendages of primary cilia and is necessary for basal body (BB) docking to the apical membrane. To investigate the function of photoreceptor CEP164 before and after BB docking, we deleted CEP164 during retina embryonic development (Six3Cre), in postnatal rod photoreceptors (iCre75) and in mature retina using tamoxifen induction (Prom1-ETCre). BBs dock to the cell cortex during postnatal day 6 (P6) to extend a connecting cilium (CC) and an axoneme. P6 retina-specific knockouts (retCep164-/-) are unable to dock BBs, thereby preventing formation of CC or outer segments (OSs). In rod-specific knockouts (rodCep164-/-), Cre expression starts after P7 and CC/OS form. P16 rodCep164-/- rods have nearly normal OS lengths, and maintain OS attachment through P21 despite loss of CEP164. Intraflagellar transport components (IFT88, IFT57 and IFT140) were reduced at P16 rodCep164-/- BBs and CC tips and nearly absent at P21, indicating impaired intraflagellar transport. Nascent OS discs, labeled with a fluorescent dye on P14 and P18 and harvested on P19, showed continued rodCep164-/- disc morphogenesis but absence of P14 discs mid-distally, indicating OS instability. Tamoxifen induction with PROM1ETCre;Cep164F/F (tamCep164-/-) adult mice affected maintenance of both rod and cone OSs. The results suggest that CEP164 is key towards recruitment and stabilization of IFT-B particles at the BB/CC. IFT impairment may be the main driver of ciliary malfunction observed with hypomorphic CEP164 mutations.


Assuntos
Corpos Basais , Corantes Fluorescentes , Animais , Corpos Basais/metabolismo , Cílios/metabolismo , Corantes Fluorescentes/metabolismo , Camundongos , Transporte Proteico/genética , Células Fotorreceptoras Retinianas Cones , Tamoxifeno
6.
Elife ; 112022 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-36004726

RESUMO

The gap junction complex functions as a transport channel across the membrane. Among gap junction subunits, gap junction protein α1 (GJA1) is the most commonly expressed subunit. A recent study showed that GJA1 is necessary for the maintenance of motile cilia; however, the molecular mechanism and function of GJA1 in ciliogenesis remain unknown. Here, we examined the functions of GJA1 during ciliogenesis in human retinal pigment epithelium-1 and Xenopus laevis embryonic multiciliated-cells. GJA1 localizes to the motile ciliary axonemes or pericentriolar regions beneath the primary cilium. GJA1 depletion caused malformation of both the primary cilium and motile cilia. Further study revealed that GJA1 depletion affected several ciliary proteins such as BBS4, CP110, and Rab11 in the pericentriolar region and basal body. Interestingly, CP110 removal from the mother centriole was significantly reduced by GJA1 depletion. Importantly, Rab11, a key regulator during ciliogenesis, was immunoprecipitated with GJA1 and GJA1 knockdown caused the mislocalization of Rab11. These findings suggest that GJA1 regulates ciliogenesis by interacting with the Rab11-Rab8 ciliary trafficking pathway.


Assuntos
Centríolos , Cílios , Animais , Corpos Basais , Centríolos/metabolismo , Centrossomo/metabolismo , Cílios/metabolismo , Conexina 43/metabolismo , Humanos , Xenopus laevis
7.
New Phytol ; 236(3): 1182-1196, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35842793

RESUMO

Land plant spermatozoids commonly possess characteristic structures such as the spline, which consists of a microtubule array, the multilayered structure (MLS) in which the uppermost layer is a continuum of the spline, and multiple flagella. However, the molecular mechanisms underpinning spermatogenesis remain to be elucidated. We successfully identified candidate genes involved in spermatogenesis, deeply divergent BLD10s, by computational analyses combining multiple methods and omics data. We then examined the functions of BLD10s in the liverwort Marchantia polymorpha and the moss Physcomitrium patens. MpBLD10 and PpBLD10 are required for normal basal body (BB) and flagella formation. Mpbld10 mutants exhibited defects in remodeling of the cytoplasm and nucleus during spermatozoid formation, and thus MpBLD10 should be involved in chromatin reorganization and elimination of the cytoplasm during spermiogenesis. We identified orthologs of MpBLD10 and PpBLD10 in diverse Streptophyta and found that MpBLD10 and PpBLD10 are orthologous to BLD10/CEP135 family proteins, which function in BB assembly. However, BLD10s evolved especially quickly in land plants and MpBLD10 might have acquired additional functions in spermatozoid formation through rapid molecular evolution.


Assuntos
Bryopsida , Marchantia , Animais , Corpos Basais , Bryopsida/genética , Cromatina/metabolismo , Gametogênese Vegetal , Marchantia/genética , Marchantia/metabolismo , Filogenia , Espermatogênese/genética
8.
J Biol Chem ; 298(7): 102125, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35697071

RESUMO

The human parasite Trypanosoma brucei contains a motile flagellum that determines the plane of cell division, controls cell morphology, and mediates cell-cell communication. During the cell cycle, inheritance of the newly formed flagellum requires its correct positioning toward the posterior of the cell, which depends on the faithful segregation of multiple flagellum-associated cytoskeletal structures including the basal body, the flagellar pocket collar, the flagellum attachment zone, and the hook complex. A specialized group of four microtubules termed the microtubule quartet (MtQ) originates from the basal body and runs through the flagellar pocket collar and the hook complex to extend, along the flagellum attachment zone, toward the anterior of the cell. However, the physiological function of the MtQ is poorly understood, and few MtQ-associated proteins have been identified and functionally characterized. We report here that an MtQ-localized protein named NHL1 interacts with the microtubule-binding protein TbSpef1 and depends on TbSpef1 for its localization to the MtQ. We show that RNAi-mediated knockdown of NHL1 impairs the segregation of flagellum-associated cytoskeletal structures, resulting in mispositioning of the new flagellum. Furthermore, knockdown of NHL1 also causes misplacement of the cell division plane in dividing trypanosome cells, halts cleavage furrow ingression, and inhibits completion of cytokinesis. These findings uncover a crucial role for the MtQ-associated protein NHL1 in regulating basal body segregation to promote flagellar inheritance in T. brucei.


Assuntos
Trypanosoma brucei brucei , Corpos Basais/metabolismo , Segregação de Cromossomos , Flagelos/metabolismo , Humanos , Microtúbulos/metabolismo , Proteínas de Protozoários/metabolismo , Trypanosoma brucei brucei/metabolismo
9.
Mol Biol Cell ; 33(11): br18, 2022 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-35767367

RESUMO

Hydrodynamic flow produced by multiciliated cells is critical for fluid circulation and cell motility. Hundreds of cilia beat with metachronal synchrony for fluid flow. Cilia-driven fluid flow produces extracellular hydrodynamic forces that cause neighboring cilia to beat in a synchronized manner. However, hydrodynamic coupling between neighboring cilia is not the sole mechanism that drives cilia synchrony. Cilia are nucleated by basal bodies (BBs) that link to each other and to the cell's cortex via BB-associated appendages. The intracellular BB and cortical network is hypothesized to synchronize ciliary beating by transmitting cilia coordination cues. The extent of intracellular ciliary connections and the nature of these stimuli remain unclear. Moreover, how BB connections influence the dynamics of individual cilia has not been established. We show by focused ion beam scanning electron microscopy imaging that cilia are coupled both longitudinally and laterally in the ciliate Tetrahymena thermophila by the underlying BB and cortical cytoskeletal network. To visualize the behavior of individual cilia in live, immobilized Tetrahymena cells, we developed Delivered Iron Particle Ubiety Live Light (DIPULL) microscopy. Quantitative and computer analyses of ciliary dynamics reveal that BB connections control ciliary waveform and coordinate ciliary beating. Loss of BB connections reduces cilia-dependent fluid flow forces.


Assuntos
Cilióforos , Tetrahymena thermophila , Corpos Basais , Cílios , Fenômenos Mecânicos
10.
J Cell Sci ; 135(10)2022 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-35575063

RESUMO

Primary cilia play a key role in the ability of cells to respond to extracellular stimuli, such as signaling molecules and environmental cues. These sensory organelles are crucial to the development of many organ systems, and defects in primary ciliogenesis lead to multisystemic genetic disorders, known as ciliopathies. Here, we review recent advances in the understanding of several key aspects of the regulation of ciliogenesis. Primary ciliogenesis is thought to take different pathways depending on cell type, and some recent studies shed new light on the cell-type-specific mechanisms regulating ciliogenesis at the apical surface in polarized epithelial cells, which are particularly relevant for many ciliopathies. Furthermore, recent findings have demonstrated the importance of actin cytoskeleton dynamics in positively and negatively regulating multiple stages of ciliogenesis, including the vesicular trafficking of ciliary components and the positioning and docking of the basal body. Finally, studies on the formation of motile cilia in multiciliated epithelial cells have revealed requirements for actin remodeling in this process too, as well as showing evidence of an additional alternative ciliogenesis pathway.


Assuntos
Citoesqueleto de Actina , Ciliopatias , Citoesqueleto de Actina/metabolismo , Actinas/metabolismo , Corpos Basais/metabolismo , Cílios/metabolismo , Ciliopatias/metabolismo , Humanos
11.
J Cell Sci ; 135(11)2022 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-35588197

RESUMO

In Trypanosoma brucei, transition fibres (TFs) form a nine-bladed pattern-like structure connecting the base of the flagellum to the flagellar pocket membrane. Despite the characterization of two TF proteins, CEP164C and T. brucei (Tb)RP2, little is known about the organization of these fibres. Here, we report the identification and characterization of the first kinetoplastid-specific TF protein, named TFK1 (Tb927.6.1180). Bioinformatics and functional domain analysis identified three distinct domains in TFK1 - an N-terminal domain of an unpredicted function, a coiled-coil domain involved in TFK1-TFK1 interaction and a C-terminal intrinsically disordered region potentially involved in protein interaction. Cellular immunolocalization showed that TFK1 is a newly identified basal body maturation marker. Furthermore, using ultrastructure expansion and immuno-electron microscopies we localized CEP164C and TbRP2 at the TF, and TFK1 on the distal appendage matrix of the TF. Importantly, RNAi-mediated knockdown of TFK1 in bloodstream form cells induced misplacement of basal bodies, a defect in the furrow or fold generation, and eventually cell death. We hypothesize that TFK1 is a basal body positioning-specific actor and a key regulator of cytokinesis in the bloodstream form Trypanosoma brucei.


Assuntos
Trypanosoma brucei brucei , Corpos Basais/metabolismo , Citocinese , Flagelos/metabolismo , Proteínas de Protozoários/metabolismo , Trypanosoma brucei brucei/metabolismo
12.
Life Sci Alliance ; 5(9)2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35550346

RESUMO

The centriole/basal body (CBB) is an evolutionarily conserved organelle acting as a microtubule organising centre (MTOC) to nucleate cilia, flagella, and the centrosome. SAS4/CPAP is a conserved component associated with BB biogenesis in many model flagellated cells. Plasmodium, a divergent unicellular eukaryote and causative agent of malaria, displays an atypical, closed mitosis with an MTOC (or centriolar plaque), reminiscent of an acentriolar MTOC, embedded in the nuclear membrane. Mitosis during male gamete formation is accompanied by flagella formation. There are two MTOCs in male gametocytes: the acentriolar nuclear envelope MTOC for the mitotic spindle and an outer centriolar MTOC (the basal body) that organises flagella assembly in the cytoplasm. We show the coordinated location, association and assembly of SAS4 with the BB component, kinesin-8B, but no association with the kinetochore protein, NDC80, indicating that SAS4 is part of the BB and outer centriolar MTOC in the cytoplasm. Deletion of the SAS4 gene produced no phenotype, indicating that it is not essential for either male gamete formation or parasite transmission.


Assuntos
Parasitos , Plasmodium , Animais , Corpos Basais/metabolismo , Centríolos/metabolismo , Masculino , Centro Organizador dos Microtúbulos/metabolismo
13.
Development ; 149(9)2022 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-35420656

RESUMO

For left-right symmetry breaking in the mouse embryo, the basal body must become positioned at the posterior side of node cells, but the precise mechanism for this has remained unknown. Here, we examined the role of microtubules (MTs) and actomyosin in this basal body positioning. Exposure of mouse embryos to agents that stabilize or destabilize MTs or F-actin impaired such positioning. Active myosin II was detected at the anterior side of node cells before the posterior shift of the basal body, and this asymmetric activation was lost in Prickle and dachsous mutant embryos. The organization of basal-body associated MTs (baMTs) was asymmetric between the anterior and posterior sides of node cells, with anterior baMTs extending horizontally and posterior baMTs extending vertically. This asymmetry became evident after polarization of the PCP core protein Vangl1 and before the posterior positioning of the basal body, and it also required the PCP core proteins Prickle and dachsous. Our results suggest that the asymmetry in baMT organization may play a role in correct positioning of the basal body for left-right symmetry breaking.


Assuntos
Corpos Basais , Polaridade Celular , Actinas/metabolismo , Animais , Polaridade Celular/fisiologia , Cílios/metabolismo , Camundongos , Microtúbulos/metabolismo
14.
Nat Commun ; 13(1): 2056, 2022 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-35440631

RESUMO

Several tissues contain cells with multiple motile cilia that generate a fluid or particle flow to support development and organ functions; defective motility causes human disease. Developmental cues orient motile cilia, but how cilia are locked into their final position to maintain a directional flow is not understood. Here we find that the actin cytoskeleton is highly dynamic during early development of multiciliated cells (MCCs). While apical actin bundles become increasingly more static, subapical actin filaments are nucleated from the distal tip of ciliary rootlets. Anchorage of these subapical actin filaments requires the presence of microridge-like structures formed during MCC development, and the activity of Nonmuscle Myosin II. Optogenetic manipulation of Ezrin, a core component of the microridge actin-anchoring complex, or inhibition of Myosin Light Chain Kinase interfere with rootlet anchorage and orientation. These observations identify microridge-like structures as an essential component of basal body rootlet anchoring in MCCs.


Assuntos
Actinas , Cílios , Citoesqueleto de Actina , Corpos Basais , Cílios/fisiologia , Citoesqueleto , Humanos
15.
J Biol Chem ; 298(3): 101686, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35131266

RESUMO

In humans, ciliary dysfunction causes ciliopathies, which present as multiple organ defects, including developmental and sensory abnormalities. Sdccag8 is a centrosomal/basal body protein essential for proper cilia formation. Gene mutations in SDCCAG8 have been found in patients with ciliopathies manifesting a broad spectrum of symptoms, including hypogonadism. Among these mutations, several that are predicted to truncate the SDCCAG8 carboxyl (C) terminus are also associated with such symptoms; however, the underlying mechanisms are poorly understood. In the present study, we identified the Sdccag8 C-terminal region (Sdccag8-C) as a module that interacts with the ciliopathy proteins, Ick/Cilk1 and Mak, which were shown to be essential for the regulation of ciliary protein trafficking and cilia length in mammals in our previous studies. We found that Sdccag8-C is essential for Sdccag8 localization to centrosomes and cilia formation in cultured cells. We then generated a mouse mutant in which Sdccag8-C was truncated (Sdccag8ΔC/ΔC mice) using a CRISPR-mediated stop codon knock-in strategy. In Sdccag8ΔC/ΔC mice, we observed abnormalities in cilia formation and ciliopathy-like organ phenotypes, including cleft palate, polydactyly, retinal degeneration, and cystic kidney, which partially overlapped with those previously observed in Ick- and Mak-deficient mice. Furthermore, Sdccag8ΔC/ΔC mice exhibited a defect in spermatogenesis, which was a previously uncharacterized phenotype of Sdccag8 dysfunction. Together, these results shed light on the molecular and pathological mechanisms underlying ciliopathies observed in patients with SDCCAG8 mutations and may advance our understanding of protein-protein interaction networks involved in cilia development.


Assuntos
Autoantígenos , Ciliopatias , Doenças Renais Císticas , Proteínas de Neoplasias , Animais , Autoantígenos/metabolismo , Corpos Basais , Cílios/metabolismo , Ciliopatias/genética , Ciliopatias/metabolismo , Feminino , Homeostase , Humanos , Doenças Renais Císticas/metabolismo , Masculino , Mamíferos , Camundongos , Mutação , Proteínas de Neoplasias/metabolismo , Proteínas/metabolismo
16.
EMBO Rep ; 23(4): e52775, 2022 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-35201641

RESUMO

Motile cilia on the cell surface generate movement and directional fluid flow that is crucial for various biological processes. Dysfunction of these cilia causes human diseases such as sinopulmonary disease and infertility. Here, we show that Ccdc108, a protein linked to male infertility, has an evolutionarily conserved requirement in motile multiciliation. Using Xenopus laevis embryos, Ccdc108 is shown to be required for the migration and docking of basal bodies to the apical membrane in epidermal multiciliated cells (MCCs). We demonstrate that Ccdc108 interacts with the IFT-B complex, and the ciliation requirement for Ift74 overlaps with Ccdc108 in MCCs. Both Ccdc108 and IFT-B proteins localize to migrating centrioles, basal bodies, and cilia in MCCs. Importantly, Ccdc108 governs the centriolar recruitment of IFT while IFT licenses the targeting of Ccdc108 to the cilium. Moreover, Ccdc108 is required for the centriolar recruitment of Drg1 and activated RhoA, factors that help establish the apical actin network in MCCs. Together, our studies indicate that Ccdc108 and IFT-B complex components cooperate in multiciliogenesis.


Assuntos
Corpos Basais , Infertilidade Masculina , Proteínas de Membrana , Proteínas de Ligação a RNA , Animais , Corpos Basais/metabolismo , Centríolos/metabolismo , Cílios/metabolismo , Proteínas do Citoesqueleto/metabolismo , Humanos , Infertilidade Masculina/genética , Masculino , Proteínas de Membrana/genética , Proteínas de Ligação a RNA/genética , Xenopus laevis
17.
J Cell Sci ; 135(4)2022 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-35067717

RESUMO

Ciliated epithelia perform essential functions in animals across evolution, ranging from locomotion of marine organisms to mucociliary clearance of airways in mammals. These epithelia are composed of multiciliated cells (MCCs) harboring myriads of motile cilia, which rest on modified centrioles called basal bodies (BBs), and beat coordinately to generate directed fluid flows. Thus, BB biogenesis and organization is central to MCC function. In basal eukaryotes, the coiled-coil domain proteins Lrrcc1 and Ccdc61 have previously been shown to be required for proper BB construction and function. Here, we used the Xenopus embryonic ciliated epidermis to characterize Lrrcc1 and Ccdc61 in vertebrate MCCs. We found that they both encode BB components, localized proximally at the junction with striated rootlets. Knocking down either gene caused defects in BB docking, spacing and polarization. Moreover, their depletion impaired the apical cytoskeleton and altered ciliary beating. Consequently, cilia-powered fluid flow was greatly reduced in morphant tadpoles, which displayed enhanced mortality when exposed to pathogenic bacteria. This work illustrates how integration across organizational scales make elementary BB components essential for the emergence of the physiological function of ciliated epithelia.


Assuntos
Corpos Basais , Cílios , Animais , Corpos Basais/metabolismo , Diferenciação Celular/fisiologia , Centríolos , Cílios/metabolismo , Xenopus laevis
18.
Methods Mol Biol ; 2364: 251-295, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34542858

RESUMO

The cytoskeletons of eukaryotic, cilioprotist microorganisms are complex, highly patterned, and diverse, reflecting the varied and elaborate swimming, feeding, reproductive, and sensory behaviors of the multitude of cilioprotist species that inhabit the aquatic environment. In the past 10-20 years, many new discoveries and technologies have helped to advance our understanding of how cytoskeletal organelles are assembled in many different eukaryotic model systems, in relation to the construction and modification of overall cellular architecture and function. Microtubule organizing centers, particularly basal bodies and centrioles, have continued to reveal their central roles in architectural engineering of the eukaryotic cell, including in the cilioprotists. This review calls attention to (1) published resources that illuminate what is known of the cilioprotist cytoskeleton; (2) recent studies on cilioprotists and other model organisms that raise specific questions regarding whether basal body- and centriole-associated nucleic acids, both DNA and RNA, should continue to be considered when seeking to employ cilioprotists as model systems for cytoskeletal research; and (3) new, mainly imaging, technologies that have already proven useful for, but also promise to enhance, future cytoskeletal research on cilioprotists.


Assuntos
Citoesqueleto , Corpos Basais , Centríolos , Centro Organizador dos Microtúbulos , Microtúbulos
19.
J Eukaryot Microbiol ; 69(5): e12880, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-34897878

RESUMO

The generation of efficient fluid flow is crucial for organismal development and homeostasis, sexual reproduction, and motility. Multi-ciliated cells possess fields of motile cilia that beat in synchrony to propel fluid. Ciliary arrays are remarkably conserved in their organization and function. Ciliates have polarized multi-ciliary arrays (MCAs) to promote fluid flow for cell motility. The ciliate cortex is decorated with hundreds of basal bodies (BB) forming linear rows along the cell's anterior-posterior axis. BBs scaffold and position cilia to form the organized ciliary array. Nascent BBs assemble at the base of BBs. As nascent BBs mature, they integrate into the cortical BB and cytoskeletal network and nucleate their own cilium. The organization of MCAs is balanced between cortical stability and cortical dynamism. The cortical cytoskeletal network both establishes and maintains a stable organization of the MCA in the face of mechanical forces exerted by ciliary beating. At the same time, MCA organization is plastic, such that it remodels for optimal ciliary mobility during development and in response to environmental conditions. Such plasticity promotes effective feeding and ecological behavior required for these organisms. Together, these properties allow an organism to effectively sense, adapt to, and move through its environment.


Assuntos
Corpos Basais , Cilióforos , Animais , Movimento Celular , Cílios/fisiologia , Cilióforos/fisiologia , Vertebrados
20.
Int J Mol Sci ; 22(22)2021 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-34830133

RESUMO

The primary cilium is found in most mammalian cells and plays a functional role in tissue homeostasis and organ development by modulating key signaling pathways. Ciliopathies are a group of genetically heterogeneous disorders resulting from defects in cilia development and function. Patients with ciliopathic disorders exhibit a range of phenotypes that include nephronophthisis (NPHP), a progressive tubulointerstitial kidney disease that commonly results in end-stage renal disease (ESRD). In recent years, distal appendages (DAPs), which radially project from the distal end of the mother centriole, have been shown to play a vital role in primary ciliary vesicle docking and the initiation of ciliogenesis. Mutations in the genes encoding these proteins can result in either a complete loss of the primary cilium, abnormal ciliary formation, or defective ciliary signaling. DAPs deficiency in humans or mice commonly results in NPHP. In this review, we outline recent advances in our understanding of the molecular functions of DAPs and how they participate in nephronophthisis development.


Assuntos
Centrossomo/metabolismo , Cílios/metabolismo , Doenças Renais Císticas/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Animais , Corpos Basais/metabolismo , Membrana Celular/metabolismo , Centríolos/metabolismo , Vesículas Citoplasmáticas/metabolismo , Humanos , Doenças Renais Císticas/congênito , Modelos Biológicos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...