Search results for "Dynein"

2017

AbstractBy moving essential body fluids and molecules, motile cilia and flagella govern respiratory mucociliary clearance, laterality determination and the transport of gametes and cerebrospinal fluid. Primary ciliary dyskinesia (PCD) is an autosomal recessive disorder frequently caused by non-assembly of dynein arm motors into cilia and flagella axonemes. Before their import into cilia and flagella, multi-subunit axonemal dynein arms are thought to be stabilized and pre-assembled in the cytoplasm through a DNAAF2–DNAAF4–HSP90 complex akin to the HSP90 co-chaperone R2TP complex. Here, we demonstrate that large genomic deletions as well as point mutations involving PIH1D3 are responsible for…

Development and validation of a method of cilia motility analysis for the early diagnosis of primary ciliary dyskinesia.

2011

Background: Primary ciliary dyskinesia (PCD) is a clinically uniform entity, but cilia motility and structure can vary between patients, making the diagnosis difficult. The aim of this study was to evaluate the sensitivity and specificity in diagnosing PCD of a system of high-resolution digital high-speed video analysis with proprietary software that we developed for analysis of ciliary motility (Desinsoft-Bio 200). The secondary aim was to correlate nasal ciliary activity with clinical and structural abnormalities in PCD. Material and methods: We analysed nasal mucociliary transport, cilia ultrastructure, nasal ciliary beat frequency and beat pattern studied by high-resolution digital high…

Ultrastructural patterns of primary ciliar dyskinesia syndrome.

2005

Clinical presentation, ciliary ultrastructure, and nasal mucociliary transport by a radioisotopic technique were analyzed in 14 Kartagener syndrome patients. In this study the most common pattern was the absence of outer and inner dynein arms in 57% of cases. Also reported are 14% patients with short inner dynein arms. A total of 29% of the patients showed normal dynein arms. Mucociliary stasis was observed in 13 cases. Primary ciliary dyskinesia syndrome and Kartagener syndrome are clinically homogeneous and morphologically heterogeneous. The authors conclude that a typical clinical presentation with an altered mucociliary transport obtained by radioisotopic technique is diagnostic althoug…

BAG3 and friends: co-chaperones in selective autophagy during aging and disease.

2011

There is a reciprocal change in the expression of two members of the BAG (Bcl-2-associated athanogen) family, BAG1 and BAG3, during cellular aging and under acute stress ("BAG1-BAG3-switch"). BAG3 was recently described as a mediator of a novel macroautophagy pathway that uses the specificity of heat shock protein 70 (HSP70) to misfolded proteins and also involves other protein partners, such as HSPB8. Also crucial for induction and execution of autophagy are sequestosome-1/p62 (SQSTM1/p62) and LC3, an autophagosome-associated protein. In this novel pathway, BAG3 mediates the targeting and transport of degradation-prone substrates into aggresomes via the microtubule-motor dynein. Interestin…

Roflumilast inhibits respiratory syncytial virus infection in human differentiated bronchial epithelial cells.

2013

Respiratory syncytial virus (RSV) causes acute exacerbations in COPD and asthma. RSV infects bronchial epithelial cells (HBE) that trigger RSV associated lung pathology. This study explores whether the phosphodiesterase 4 (PDE4) inhibitor Roflumilast N-oxide (RNO), alters RSV infection of well-differentiated HBE (WD-HBE) in vitro. WD-HBE were RSV infected in the presence or absence of RNO (0.1-100 nM). Viral infection (staining of F and G proteins, nucleoprotein RNA level), mRNA of ICAM-1, ciliated cell markers (digital high speed videomicroscopy, β-tubulin immunofluorescence, Foxj1 and Dnai2 mRNA), Goblet cells (PAS), mRNA of MUC5AC and CLCA1, mRNA and protein level of IL-13, IL-6, IL-8, T…

Rhodopsin's carboxy-terminal cytoplasmic tail acts as a membrane receptor for cytoplasmic dynein by binding to the dynein light chain Tctex-1.

1999

AbstractThe interaction of cytoplasmic dynein with its cargoes is thought to be indirectly mediated by dynactin, a complex that binds to the dynein intermediate chain. However, the roles of other dynein subunits in cargo binding have been unknown. Here we demonstrate that dynein translocates rhodopsin-bearing vesicles along microtubules. This interaction occurs directly between the C-terminal cytoplasmic tail of rhodopsin and Tctex-1, a dynein light chain. C-terminal rhodopsin mutations responsible for retinitis pigmentosa inhibit this interaction. Our results point to an alternative docking mechanism for cytoplasmic dynein, provide novel insights into the role of motor proteins in the pola…

Myosin VIIa, harmonin and cadherin 23, three Usher I gene products that cooperate to shape the sensory hair cell bundle

2002

Deaf-blindness in three distinct genetic forms of Usher type I syndrome (USH1) is caused by defects in myosin VIIa, harmonin and cadherin 23. Despite being critical for hearing, the functions of these proteins in the inner ear remain elusive. Here we show that harmonin, a PDZ domain-containing protein, and cadherin 23 are both present in the growing stereocilia and that they bind to each other. Moreover, we demonstrate that harmonin b is an F-actin-bundling protein, which is thus likely to anchor cadherin 23 to the stereocilia microfilaments, thereby identifying a novel anchorage mode of the cadherins to the actin cytoskeleton. Moreover, harmonin b interacts directly with myosin VIIa, and i…

Identification of the dynein light chains required for human papillomavirus infection

2010

Summary Human papillomaviruses (HPVs) are a family of small non-enveloped DNA viruses. Some genital HPV types, including HPV type 16 (HPV16), are the causative agent for the development of cancer at the site of infection. HPVs encode two capsid proteins, L1 and L2. After endocytic cell entry and egress from endosomes, L2 accompanies the viral DNA to the nucleus where replication is initiated. For cytoplasmic transport, L2 interacts with the microtubule network via the motor protein complex dynein. We have performed yeast two-hybrid screening and identified the dynein light chain DYNLT1 (previously called Tctex1) as interaction partner of HPV16 L2. Using co-immunoprecipitation and immunofluo…

Differential Distribution of Harmonin Isoforms and Their Possible Role in Usher-1 Protein Complexes in Mammalian Photoreceptor Cells

2003

PURPOSE. Human Usher syndrome is the most common form of combined deafness and blindness. Usher type I (USH1), the most severe form, is characterized by profound congenital deafness, constant vestibular dysfunction, and prepubertal onset retinitis pigmentosa. Previous studies have shown that the USH1-proteins myosin VIIa, harmonin, and cadherin 23 interact and form a functional network during hair cell differentiation in the inner ear. The purpose of the present study was to analyze the molecular and cellular functions of these USH1 proteins in the mammalian retina. METHODS. Antibodies to USH1 proteins were generated and used in Western blot analysis of subcellular photoreceptor fractions a…

Identification of a Dynein Interacting Domain in the Papillomavirus Minor Capsid Protein L2

2006

ABSTRACT Papillomaviruses enter cells via endocytosis (H. C. Selinka et al., Virology 299:279-287, 2002). After egress from endosomes, the minor capsid protein L2 accompanies the viral DNA to the nucleus and subsequently to the subnuclear promyelocytic leukemia protein bodies (P. M. Day et al., Proc. Natl. Acad. Sci. USA 101:14252-14257, 2004), suggesting that this protein may be involved in the intracytoplasmic transport of the viral genome. We now demonstrate that the L2 protein is able to interact with the microtubule network via the motor protein dynein. L2 protein was found attached to microtubules after uncoating of incoming human papillomavirus pseudovirions. Based on immunofluoresce…