Search results for "Ilium"

Septins 2, 7 and 9 and MAP4 colocalize along the axoneme in the primary cilium and control ciliary length

2013

International audience; Septins are a large, evolutionarily conserved family of GTPases that form hetero-oligomers and interact with the actin-based cytoskeleton and microtubules. They are involved in scaffolding functions, and form diffusion barriers in budding yeast, the sperm flagellum and the base of primary cilia of kidney epithelial cells. We investigated the role of septins in the primary cilium of retinal pigmented epithelial (RPE) cells, and found that SEPT2 forms a 1:1:1 complex with SEPT7 and SEPT9 and that the three members of this complex colocalize along the length of the axoneme. Similar to observations in kidney epithelial cells, depletion of cilium-localized septins by siRN…

Ciliopathies: an Update

2015

Cilia are hair-like organelles that extend from the surface of almost all human cells. Nine doublet microtubule pairs make up the core of each cilium, known as the axoneme. Cilia are classified as motile or immotile; non motile or primary cilia are involved in sensing the extracellular environment. These organelles mediate perception of chemo-, mechano- and osmosensations that are then transmitted into the cell via signaling pathways. They also play a crucial role in cellular functions including planar cell polarity, cell division, proliferation and apoptosis. Because of cilia are located on almost all polarized human cell types, cilia-related disorders, can affect many organs and systems. …

Different roles for KIF17 and kinesin II in photoreceptor development and maintenance.

2009

Kinesin 2 family members are involved in transport along ciliary microtubules. In Caenorhabditis elegans channel cilia, kinesin II and OSM-3 cooperate along microtubule doublets of the axoneme middle segment, whereas OSM-3 alone works on microtubule singlets to elongate the distal segment. Among sensory cilia, vertebrate photoreceptors share a similar axonemal structure with C. elegans channel cilia, and deficiency in either kinesin II or KIF17, the homologue of OSM-3, results in disruption of photoreceptor organization. However, direct comparison of the two effects is confounded by the use of different species and knockdown strategies in prior studies. Here, we directly compare the effects…

A novel function of Huntingtin in the cilium and retinal ciliopathy in Huntington's disease mice

2015

Huntington's disease (HD) is a neurodegenerative disorder caused by the toxic expansion of polyglutamine in the Huntingtin (HTT) protein. The pathomechanism is complex and not fully understood. Increasing evidence indicates that the loss of normal protein function also contributes to the pathogenesis, pointing out the importance of understanding the physiological roles of HTT. We provide evidence for a novel function of HTT in the cilium. HTT localizes in diverse types of cilia — including 9 + 0 non-motile sensory cilia of neurons and 9 + 2 motile multicilia of trachea and ependymal cells — which exert various functions during tissue development and homeostasis. In the photoreceptor cilium,…

Protein Networks and Complexes in Photoreceptor Cilia

2007

Vertebrate photoreceptor cells are ciliated sensory cells specialized for single photon detection. The photoreceptor outer segment corresponds to the ciliary shaft of a prototypic cilium. In the outer segment compartment, the ciliary membrane is highly modified into membranous disks which are enveloped by the plasma membrane in rod cells. At these outer segment disks, the visual transduction cascade--a prototypical G-protein coupled receptor transduction pathway is arranged. The light sensitive outer segments are linked by the socalled connecting cilium with the inner segment, the photoreceptor compartment which contains all organelles necessary for cell metabolism. The connecting cilium co…

A new styracosternan hadrosauroid (Dinosauria: Ornithischia) from the Early Cretaceous of Portell, Spain

2021

A new styracosternan ornithopod genus and species is described based on the right dentary of a single specimen from the Mirambell Formation (Early Cretaceous, early Barremian) at the locality of Portell, (Castellón, Spain).Portellsaurus sosbaynatigen. et sp. nov. is diagnosed by two autapomorphic features as well as a unique combination of characters. The autapomorphies include: the absence of a bulge along the ventral margin directly ventral to the base of the coronoid process and the presence of a deep oval cavity on the medial surface of the mandibular adductor fossa below the eleventh-twelfth tooth position. Phylogenetic analyses reveal that the new Iberian form is more closely related …

Sensory hybrid host materials for the selective chromo-fluorogenic detection of biogenic amines

2006

[EN] Pyrylium-containing mesoporous materials have been used for the chromo-fluorogenic sensing of biogenic amines in an aqueous environment.

A ciliopathy complex builds distal appendages to initiate ciliogenesis

2021

ABSTRACTCells inherit two centrioles, the older of which is uniquely capable of generating a cilium. Using proteomics and super-resolved imaging, we identified a module which we term DISCO (DIStal centriole COmplex). DISCO components CEP90, MNR and OFD1 underlie human ciliopathies. This complex localized to both distal centrioles and centriolar satellites, proteinaceous granules surrounding centrioles. Cells and mice lacking CEP90 or MNR did not generate cilia, failed to assemble distal appendages, and did not transduce Hedgehog signals. Disrupting the satellite pools did not affect distal appendage assembly, indicating that it is the centriolar populations of MNR and CEP90 that are critica…

A Ciliary Motility Index for Activity Measurement in Cell Cultures With Respiratory Syncytial Virus

2018

[EN] Background: The respiratory epithelium is frequently infected by the respiratory syncytial virus, resulting in inflammation, a reduction in cilia activity and an increase in the production of mucus. Methods: In this study, an automatic method has been proposed to characterize the ciliary motility from cell cultures by means of a motility index using a dense optical flow algorithm. This method allows us to determine the ciliary beat frequency (CBF) together with a ciliary motility index of the cells in the cultures. The object of this analysis is to automatically distinguish between normal and infected cells in a culture. Results: The method was applied in 2 stages. It was concluded fro…

2020

Cilia are cellular organelles that project from the cell. They occur in nearly all non-hematopoietic tissues and have different functions in different tissues. In mesenchymal tissues primary cilia play a crucial role in the adequate morphogenesis during embryological development. In mature articular cartilage, primary cilia fulfil chemo- and mechanosensitive functions to adapt the cellular mechanisms on extracellular changes and thus, maintain tissue homeostasis and morphometry. Ciliary abnormalities in osteoarthritic cartilage could represent pathophysiological relationships between ciliary dysfunction and tissue deformation. Nevertheless, the molecular and pathophysiological relationships…