The Experts below are selected from a list of 1857 Experts worldwide ranked by ideXlab platform

Hiroyuki Takeda - One of the best experts on this subject based on the ideXlab platform.

  • Systematic studies of all PIH proteins in zebrafish reveal their distinct roles in Axonemal Dynein assembly.
    eLife, 2018
    Co-Authors: Hiroshi Yamaguchi, Toshiyuki Oda, Masahide Kikkawa, Hiroyuki Takeda
    Abstract:

    Many cells have long, thin structures called cilia on their surface, some types of which can beat back and forth. This beating motion has many roles; for example, cilia on the cells that line the lungs help to sweep out debris, and the tails of sperm beat to move them forward. A structure called the Axonemal Dynein complex at the core of the cilia generates the beating motion. When the cell makes new cilia, it assembles the complexes in the main body of the cell and then transports them to the right place, like erecting a prefabricated building. Various proteins help to assemble the complexes, of which there are more than eight types. However, the identities of all of these proteins, and their roles in constructing specific Axonemal Dynein complexes, is not fully known. Studies in algae have suggested that a family of proteins known as PIH (short for protein interacting with Hsp90) helps to construct Axonemal Dynein complexes. Zebrafish – which share many of the same protein-encoding genes as humans – produce four PIH family proteins. To investigate the roles that each of these proteins play, Yamaguchi et al. used genetic engineering to create four zebrafish mutants that were each unable to produce a different PIH protein. A technique called cryo-electron microscopy enabled the Axonemal Dynein complexes in the tails of the sperm produced by the zebrafish to be visualized. The sperm from each mutant lacked specific Axonemal Dynein complexes, revealing that each PIH protein assembles different complexes. The sperm also had difficulties moving. Yamaguchi et al. examined this movement to deduce how specific complexes affect the ability of the sperm to beat their tails. Further work on how PIH proteins interact with the Axonemal Dynein complexes will help us to understand how cells make cilia, and what happens when this process goes wrong. This could ultimately help us to treat genetic disorders known as ciliopathies, which arise when cilia do not develop normally.

  • ZMYND10 functions in a chaperone relay during Axonemal Dynein assembly
    2017
    Co-Authors: Girish R Mali, Patricia L. Yeyati, Seiya Mizuno, Margaret A. Keighren, Petra I. Zur Lage, Amaya Garcia-munoz, Atsuko Shimada, Hiroyuki Takeda, Frank Edlich, Satoru Takahashi
    Abstract:

    Molecular chaperones promote the folding and macromolecular assembly of a diverse set of substrate 'client' proteins. How the ubiquitous chaperone machinery directs its activities towards a specific set of substrates and whether this selectivity could be targeted for therapeutic intervention is of intense research. Through the use of mouse genetics, imaging and quantitative proteomics we uncover that ZMYND10 is a novel co-chaperone for the FKBP8-HSP90 chaperone complex during the biosynthesis of Axonemal Dynein heavy chains required for cilia motility. In the absence of ZMYND10, defects in Dynein heavy chains trigger broader Dynein motor degradation. We show that FKBP8 inhibition phenocopies Dynein motor instability in airway cells, and human disease-causing variants of ZMYND10 disrupt its ability to act as FKBP8-HSP90 co-chaperone. Our study indicates that the motile ciliopathy Primary Ciliary Dyskinesia (PCD) should be considered a cell-type specific protein-misfolding disease and opens the potential for rational drug design that could restore specificity to the ubiquitous chaperone apparatus towards Dynein subunits.

  • Pih1d3 is required for cytoplasmic preassembly of Axonemal Dynein in mouse sperm
    The Journal of cell biology, 2014
    Co-Authors: Fenglan Dong, Hiroyuki Takeda, Kyosuke Shinohara, Yanick Botilde, Ryo Nabeshima, Yasuko Asai, Akemi Fukumoto, Toshiaki Hasegawa, Moe Matsuo, Hidetaka Shiratori
    Abstract:

    Axonemal Dynein complexes are preassembled in the cytoplasm before their transport to cilia, but the mechanism of this process remains unclear. We now show that mice lacking Pih1d3, a PIH1 domain–containing protein, develop normally but manifest male sterility. Pih1d3−/− sperm were immotile and fragile, with the axoneme of the flagellum lacking outer Dynein arms (ODAs) and inner Dynein arms (IDAs) and showing a disturbed 9+2 microtubule organization. Pih1d3 was expressed specifically in spermatogenic cells, with the mRNA being most abundant in pachytene spermatocytes. Pih1d3 localized to the cytoplasm of spermatogenic cells but was not detected in spermatids or mature sperm. The levels of ODA and IDA proteins were reduced in the mutant testis and sperm, and Pih1d3 was found to interact with an intermediate chain of ODA as well as with Hsp70 and Hsp90. Our results suggest that Pih1d3 contributes to cytoplasmic preassembly of Dynein complexes in spermatogenic cells by stabilizing and promoting complex formation by ODA and IDA proteins.

  • Ciliary motility: the components and cytoplasmic preassembly mechanisms of the Axonemal Dyneins.
    Differentiation; research in biological diversity, 2011
    Co-Authors: Daisuke Kobayashi, Hiroyuki Takeda
    Abstract:

    Motile cilia and flagella are organelles, which function in cell motility and in the transport of fluids over the surface of cells. Motility defects often result in a rare human disease, primary ciliary dyskinesia (PCD). Cell motility depends on Axonemal Dynein, a molecular motor that drives the beating of cilia and flagella. The Dyneins are composed of multiple subunits, which are thought to be preassembled in the cytoplasm before they are transported into cilia and flagella. Axonemal Dyneins have been extensively studied in Chlamydomonas. In addition, analyses of human PCDs over the past decade, together with studies in other model animals, have identified the conserved components required for Dynein assembly. Recently also, the first cytoplasmic component of Dynein assembly, kintoun (ktu), was elucidated through the analysis of a medaka mutant in combination with human genetics and cell biology and biochemical studies of Chlamydomonas. The components of Dynein and the proteins involved in its cytoplasmic assembly process are discussed.

  • characterization of the medaka oryzias latipes primary ciliary dyskinesia mutant jaodori redundant and distinct roles of Dynein Axonemal intermediate chain 2 dnai2 in motile cilia
    Developmental Biology, 2010
    Co-Authors: Daisuke Kobayashi, Hiroyuki Takeda, Norio Iijima, Haruo Hagiwara, Keiichiro Kamura, Takahiko Yokoyama
    Abstract:

    Cilia and flagella are highly conserved organelles that have diverse motility and sensory functions. Motility defects in cilia and flagella result in primary ciliary dyskinesia (PCD). We isolated a novel medaka PCD mutant, jaodori (joi). Positional cloning showed that Axonemal Dynein intermediate chain 2 (dnai2) is responsible for joi. The joi mutation was caused by genomic insertion of the medaka transposon, Tol1. In the joi mutant, cilia in Kupffer's vesicle (KV), an organ functionally equivalent to the mouse node in terms of left-right (LR) specification, are generated but their motility is disrupted, resulting in a LR defect. Ultrastructural analysis revealed severe reduction in the outer Dynein arms in KV cilia of joi mutants. We also found the other dnai2 gene in the medaka genome. These two dnai2 genes function either redundantly or distinctly in tissues possessing motile cilia.

Masaki Edamatsu - One of the best experts on this subject based on the ideXlab platform.

  • Motor domain-based motility system and motile properties of alpha heavy chain in Tetrahymena outer arm Dynein
    Biochemical and biophysical research communications, 2014
    Co-Authors: Masaki Edamatsu
    Abstract:

    Axonemal Dynein plays an essential role in ciliary motility, and impaired ciliary motility causes human diseases such as primary ciliary dyskinesia (PCD). The motor domain of Axonemal Dynein powers ciliary motility and its function is regulated by several accessary proteins bound to the tail region. Therefore, to understand the essential properties of Dynein motility, examining the motile properties of the motor domain without the tail is necessary. In this study, the functional motor domain of the alpha heavy chain in Tetrahymena outer arm Dynein was purified, and its motile properties were examined using an in vitro motility system. The purified protein caused microtubules to glide at a velocity of 5.0μm/s with their minus-end trailing, and motility was inhibited in an ATP concentration-dependent manner, which is in contrast with kinesin1. This method could be applicable to other Axonemal Dyneins and will enable further molecular studies on diverse Axonemal Dyneins and ciliary motility.

  • Identification of biotin carboxyl carrier protein in Tetrahymena and its application in in vitro motility systems of outer arm Dynein.
    Journal of microbiological methods, 2014
    Co-Authors: Masaki Edamatsu
    Abstract:

    Axonemal Dynein plays a central role in ciliary beating. Recently, a functional expression system of Axonemal Dynein was established in the ciliated protozoan Tetrahymena. This study identifies biotin carboxyl carrier protein (BCCP) in Tetrahymena and demonstrates its application in in vitro motility systems of outer arm Dynein.

  • The functional expression and motile properties of recombinant outer arm Dynein from Tetrahymena
    Biochemical and Biophysical Research Communications, 2014
    Co-Authors: Masaki Edamatsu
    Abstract:

    Abstract Cilia and flagella are motile organelles that play various roles in eukaryotic cells. Ciliary movement is driven by Axonemal Dyneins (outer arm and inner arm Dyneins) that bind to peripheral microtubule doublets. Elucidating the molecular mechanism of ciliary movement requires the genetic engineering of Axonemal Dyneins; however, no expression system for Axonemal Dyneins has been previously established. This study is the first to purify recombinant Axonemal Dynein with motile activity. In the ciliated protozoan Tetrahymena, recombinant outer arm Dynein purified from ciliary extract was able to slide microtubules in a gliding assay. Furthermore, the recombinant Dynein moved processively along microtubules in a single-molecule motility assay. This expression system will be useful for investigating the unique properties of diverse Axonemal Dyneins and will enable future molecular studies on ciliary movement.

Stephen M. King - One of the best experts on this subject based on the ideXlab platform.

  • WDR92 is required for Axonemal Dynein heavy chain stability in cytoplasm
    Molecular biology of the cell, 2019
    Co-Authors: Ramila S. Patel-king, Miho Sakato-antoku, Maya Yankova, Stephen M. King
    Abstract:

    WDR92 associates with a prefoldin-like cochaperone complex and known Dynein assembly factors. WDR92 has been very highly conserved and has a phylogenetic signature consistent with it playing a role in motile ciliary assembly or activity. Knockdown of WDR92 expression in planaria resulted in ciliary loss, reduced beat frequency and dyskinetic motion of the remaining ventral cilia. We have now identified a Chlamydomonas wdr92 mutant that encodes a protein missing the last four WD repeats. The wdr92-1 mutant builds only ∼0.7-μm cilia lacking both inner and outer Dynein arms, but with intact doublet microtubules and central pair. When cytoplasmic extracts prepared by freeze/thaw from a control strain were fractionated by gel filtration, outer arm Dynein components were present in several distinct high molecular weight complexes. In contrast, wdr92-1 extracts almost completely lacked all three outer arm heavy chains, while the IFT Dynein heavy chain was present in normal amounts. A wdr92-1 tpg1-2 double mutant builds ∼7-μm immotile flaccid cilia that completely lack Dynein arms. These data indicate that WDR92 is a key assembly factor specifically required for the stability of Axonemal Dynein heavy chains in cytoplasm and suggest that cytoplasmic/IFT Dynein heavy chains use a distinct folding pathway.

  • Axonemal Dynein Arms
    Cold Spring Harbor perspectives in biology, 2016
    Co-Authors: Stephen M. King
    Abstract:

    Axonemal Dyneins form the inner and outer rows of arms associated with the doublet microtubules of motile cilia. These enzymes convert the chemical energy released from adenosine triphosphate (ATP) hydrolysis into mechanical work by causing the doublets to slide with respect to each other. Dyneins form two major groups based on the number of heavy-chain motors within each complex. In addition, these enzymes contain other components that are required for assembly of the complete particles and/or for the regulation of motor function in response to phosphorylations status, ligands such as Ca2+, changes in cellular redox state and which also apparently monitor and respond to the mechanical state or curvature in which any given motor finds itself. It is this latter property, which is thought to result in waves of motor function propagating along the axoneme length. Here, I briefly describe our current understanding of Axonemal Dynein structure, assembly, and organization.

  • integrated control of Axonemal Dynein aaa motors
    Journal of Structural Biology, 2012
    Co-Authors: Stephen M. King
    Abstract:

    Axonemal Dyneins are AAA+ enzymes that convert ATP hydrolysis to mechanical work. This leads to the sliding of doublet microtubules with respect to each other and ultimately the generation of ciliary/flagellar beating. However, in order for useful work to be generated, the action of individual Dynein motors must be precisely controlled. In addition, cells modulate the motility of these organelles through a variety of second messenger systems and these signals too must be integrated by the Dynein motors to yield an appropriate output. This review describes the current status of efforts to understand Dynein control mechanisms and their connectivity focusing mainly on studies of the outer Dynein arm from axonemes of the unicellular biflagellate green alga Chlamydomonas.

  • Integrated control of Axonemal Dynein AAA(+) motors.
    Journal of structural biology, 2012
    Co-Authors: Stephen M. King
    Abstract:

    Axonemal Dyneins are AAA+ enzymes that convert ATP hydrolysis to mechanical work. This leads to the sliding of doublet microtubules with respect to each other and ultimately the generation of ciliary/flagellar beating. However, in order for useful work to be generated, the action of individual Dynein motors must be precisely controlled. In addition, cells modulate the motility of these organelles through a variety of second messenger systems and these signals too must be integrated by the Dynein motors to yield an appropriate output. This review describes the current status of efforts to understand Dynein control mechanisms and their connectivity focusing mainly on studies of the outer Dynein arm from axonemes of the unicellular biflagellate green alga Chlamydomonas.

  • A novel Tctex2-related light chain is required for stability of inner Dynein arm I1 and motor function in the Chlamydomonas flagellum.
    The Journal of biological chemistry, 2004
    Co-Authors: Linda M. Dibella, Ramila S. Patel-king, Elizabeth F. Smith, Ken-ichi Wakabayashi, Stephen M. King
    Abstract:

    Tctex1 and Tctex2 were originally described in mice as putative distorters/sterility factors involved in the non-Mendelian transmission of t haplotypes. Subsequently, these proteins were found to be light chains of both cytoplasmic and Axonemal Dyneins. We have now identified a novel Tctex2-related protein (Tctex2b) within the Chlamydomonas flagellum. Tctex2b copurifies with inner arm I1 after both sucrose gradient centrifugation and anion exchange chromatography. Unlike the Tctex2 homologue within the outer Dynein arm, analysis of a Tctex2b-null strain indicates that this protein is not essential for assembly of inner arm I1. However, a lack of Tctex2b results in an unstable Dynein particle that disassembles after high salt extraction from the axoneme. Cells lacking Tctex2b swim more slowly than wild type and exhibit a reduced flagellar beat frequency. Furthermore, using a microtubule sliding assay we observed that Dynein motor function is reduced in vitro. These data indicate that Tctex2b is required for the stability of inner Dynein arm I1 and wild-type Axonemal Dynein function.

Ritsu Kamiya - One of the best experts on this subject based on the ideXlab platform.

  • Genetic Approaches to Axonemal Dynein Function in Chlamydomonas and Other Organisms
    Dyneins, 2012
    Co-Authors: Toshiki Yagi, Ritsu Kamiya
    Abstract:

    Publisher Summary This chapter elucidates the role of genetic studies in understanding the Axonemal Dynein function in various organisms. Forward and reverse genetic studies of Axonemal Dynein indicate that the functional characteristics of various types of Dyneins are well conserved among organisms. Genetic studies of Axonemal Dynein have been most extensively carried out using Chlamydomonas, a unicellular organism that yields a variety of flagella-deficient mutants. Most Dynein components identified in Chlamydomonas have homologs in vertebrates and other ciliated organisms. Therefore, the forward genetic approach using Chlamydomonas has greatly contributed to the studies of Axonemal Dyneins in general. The study begins with discussing the genetic research carried out on Chlamydomonas Axonemal Dyneins. Chlamydomonas Dynein-deficient mutants are isolated from cells displaying slow swimming or non-motile phenotypes, and the isolation mechanism is explained. Chlamydomonas Axonemal Dyneins are comprised of three distinct types of Dyneins: an outer-arm Dynein containing three HCs, a two-headed inner-arm Dynein (containing two HCs), and multiple species of single-headed Dyneins. Other than Chlamydomonas, mutants deficient in Axonemal Dyneins have been obtained in several unicellular and multicellular organisms, such as, tetrahymena, trypanosoma, zebrafish, medaka, frog, mouse, and, finally, human. In most cases, mutants were generated by reverse genetics techniques, using information from genome databases. The summaries of each of the research studies carried out on these organisms are presented.

  • strikingly fast microtubule sliding in bundles formed by chlamydomonas Axonemal Dynein
    Cytoskeleton, 2010
    Co-Authors: Susumu Aoyama, Ritsu Kamiya
    Abstract:

    Chlamydomonas Axonemal extracts containing outer-arm Dynein bundle microtubules when added in the absence of ATP. The bundles dissociate after addition of ATP (Haimo et al., Proc Natl Acad Sci USA 76:5759-5768, 1979). In the present study, we investigated the ATP-induced bundle dissociation process using caged ATP. Application of approximately 0.5 mM ATP induced microtubule sliding at approximately 30 microm.s(-1), which was 1.5 times faster than the microtubule sliding observed in protease-treated axonemes and five times faster than microtubule gliding on glass surfaces coated with outer-arm Dynein. Bundles formed by mutant Dynein molecules that lack one of the three heavy chains (HCs) displayed similar high-speed intermicrotubule sliding. These results suggest that Chlamydomonas outer-arm Dynein molecules, when aligned, can translocate microtubules at high speed and that the high-speed sliding under load-free conditions does not require the complete set of the three HCs. It is likely that each of the three HCs has the ability to produce high-speed sliding, which should be an important property for their cooperation.

  • novel 44 kilodalton subunit of Axonemal Dynein conserved from chlamydomonas to mammals
    Eukaryotic Cell, 2008
    Co-Authors: Ryosuke Yamamoto, Toshiki Yagi, Haruaki Yanagisawa, Ritsu Kamiya
    Abstract:

    Cilia and flagella have multiple Dyneins in their inner and outer arms. Chlamydomonas inner-arm Dynein contains at least seven major subspecies (Dynein a to Dynein g), of which all but Dynein f (also called Dynein I1) are the single-headed type that are composed of a single heavy chain, actin, and either centrin or a 28-kDa protein (p28). Dynein d was found to associate with two additional proteins of 38 kDa (p38) and 44 kDa (p44). Following the characterization of the p38 protein (R. Yamamoto, H. A. Yanagisawa, T. Yagi, and R. Kamiya, FEBS Lett. 580:6357-6360, 2006), we have identified p44 as a novel component of Dynein d by using an immunoprecipitation approach. p44 is present along the length of the axonemes and is diminished, but not absent, in the ida4 and ida5 mutants, both lacking this Dynein. In the ida5 axoneme, p44 and p38 appear to form a complex, suggesting that they constitute the docking site of Dynein d on the outer doublet. p44 has potential homologues in other ciliated organisms. For example, the mouse homologue of p44, NYD-SP14, was found to be strongly expressed in tissues with motile cilia and flagella. These results suggest that inner-arm Dynein d and its subunit organization are widely conserved.

  • a novel subunit of Axonemal Dynein conserved among lower and higher eukaryotes
    FEBS Letters, 2006
    Co-Authors: Ryosuke Yamamoto, Toshiki Yagi, Haruaki Yanagisawa, Ritsu Kamiya
    Abstract:

    To elucidate the subunit composition of Axonemal inner-arm Dynein, we examined a 38 kDa protein (p38) co-purified with a Chlamydomonas inner arm subspecies, Dynein d. We found it is a novel protein conserved among a variety of organisms with motile cilia and flagella. Immunoprecipitation using specific antibody verified its association with a heavy chain, actin and a previously identified light chain (p28). Unexpectedly, mutant axonemes lacking Dynein d and other Dyneins retained reduced amounts of p38. This finding suggests that p38 is involved in the docking of Dynein d to specific loci.

  • slow adp dependent acceleration of microtubule translocation produced by an Axonemal Dynein
    FEBS Letters, 2004
    Co-Authors: Kenji Kikushima, Toshiki Yagi, Ritsu Kamiya
    Abstract:

    Dynein has four nucleotide binding sites, of which the functional significance is unknown except for the single catalytic site. To obtain clues to the function of non-catalytic nucleotide binding, we examined the effect of ADP on the in vitro motility of Chlamydomonas inner-arm Dynein species ‘a’. Upon continuous perfusion with ATP and ADP, microtubules glided on a Dynein-coated glass surface with a velocity that gradually increased over a few minutes. The velocity increased faster at higher ADP concentrations. These results suggest that this Dynein is activated by nucleotide binding to regulatory site(s) through an extremely slow process.

Albert M. Collier - One of the best experts on this subject based on the ideXlab platform.

  • Axonemal Dynein expression in human fetal tracheal epithelium.
    American journal of physiology. Lung cellular and molecular physiology, 2002
    Co-Authors: Johnny L. Carson, William Reed, Thomas Lucier, Luisa E. Brighton, Todd M. Gambling, Chien-hui Huang, Albert M. Collier
    Abstract:

    Ciliogenesis in human fetal airway epithelium occurs from 11 to 24 gestational weeks. Using genetic and antigenic markers specific for human Axonemal Dynein heavy chain 9, we characterized temporal...

  • Axonemal Dynein expression in human fetal tracheal epithelium : Pre- and postnatal lung development, maturation, and plasticity
    American Journal of Physiology-lung Cellular and Molecular Physiology, 2002
    Co-Authors: Johnny L. Carson, William Reed, Thomas Lucier, Luisa E. Brighton, Todd M. Gambling, Chien-hui Huang, Albert M. Collier
    Abstract:

    Ciliogenesis in human fetal airway epithelium occurs from 11 to 24 gestational weeks. Using genetic and antigenic markers specific for human Axonemal Dynein heavy chain 9, we characterized temporal aspects of Axonemal Dynein expression associated with large airway epithelial ciliogenesis during human fetal development. Late in the first trimester, an undifferentiated columnar epithelium is characteristic of the large airways, and immunocytochemical studies exhibited focal localization of Axonemal Dynein antigen on luminal epithelial cell borders at sites consistent with emergent ciliary beds. From 12 to 22 wk, immunocytochemical labeling of new ciliary beds was prominent, and localization within the cytoplasm of epithelial cells suggested avid synthesis of Axonemal Dynein in advance of ciliogenic events. Quantitative RT-PCR of tracheal RNA and in situ hybridization studies compared favorably with immunocytochemical findings with the earliest expression of Axonemal Dynein at 9-10 wk gestation. These studies have documented that Axonemal Dynein is expressed early in human fetal life during airway epithelial maturation and well before histological or ultrastructural evidence of ciliogenesis is apparent.

  • Pre- and Postnatal Lung Development, Maturation, and Plasticity Axonemal Dynein expression in human fetal tracheal epithelium
    2002
    Co-Authors: Johnny L. Carson, William Reed, Thomas Lucier, Luisa E. Brighton, Todd M. Gambling, Chien-hui Huang, Albert M. Collier, L Johnny
    Abstract:

    Carson, Johnny L., William Reed, Thomas Lucier, Luisa Brighton, Todd M. Gambling, Chien-Hui Huang, and Albert M. Collier. Axonemal Dynein expression in human fetal tracheal epithelium. Am J Physiol Lung Cell Mol Physiol 282: L421–L430, 2002. First published November 16, 2001; 10.1152/ajplung.00147.2001.—Ciliogenesis in human fetal airway epithelium occurs from 11 to 24 gestational weeks. Using genetic and antigenic markers specific for human Axonemal Dynein heavy chain 9, we characterized temporal aspects of Axonemal Dynein expression associated with large airway epithelial ciliogenesis during human fetal development. Late in the first trimester, an undifferentiated columnar epithelium is characteristic of the large airways, and immunocytochemical studies exhibited focal localization of Axonemal Dynein antigen on luminal epithelial cell borders at sites consistent with emergent ciliary beds. From 12 to 22 wk, immunocytochemical labeling of new ciliary beds was prominent, and localization within the cytoplasm of epithelial cells suggested avid synthesis of Axonemal Dynein in advance of ciliogenic events. Quantitative RT-PCR of tracheal RNA and in situ hybridization studies compared favorably with immunocytochemical findings with the earliest expression of Axonemal Dynein at 9–10 wk gestation. These studies have documented that Axonemal Dynein is expressed early in human fetal life during airway epithelial maturation and well before histological or ultrastructural evidence of ciliogenesis is apparent.

  • characterization of an Axonemal Dynein heavy chain expressed early in airway epithelial ciliogenesis
    American Journal of Respiratory Cell and Molecular Biology, 2000
    Co-Authors: William Reed, Johnny L. Carson, Thomas Lucier, Luisa E. Brighton, Todd M. Gambling, Chien-hui Huang, Billie M Moatsstaats, Margaret W Leigh, Albert M. Collier
    Abstract:

    The most conspicuous evidence of airway epithelial maturation and vitality is the presence of motile cilia. In an effort to generate genetic and antigenic markers of airway maturation, injury, and repair, we characterized airway epithelial expression of a gene identified by two human expressed sequence tags that encoded peptides with sequence similarity to an invertebrate ciliary Dynein heavy chain (DHC). Molecular analyses showed that the gene has a very large RNA transcript that encodes a very high molecular weight polypeptide with biochemical properties that are characteristic of a Dynein heavy chain. Expression of the gene transcript correlated with the presence of ciliated cells in tissues, and immunohistochemical localization of the gene product confirmed its presence in the cilia of mature airway epithelium. In epithelium undergoing ciliogenesis ex vivo, expression of the gene transcript preceded ciliation of the epithelium and the gene product was present in the cytoplasm and at the apical border ...

  • Ciliogenesis and Axonemal Dynein Expression in Human Airway Epithelium Cultured in an Air/Liquid Interface Environment
    Microscopy and Microanalysis, 1998
    Co-Authors: Johnny L. Carson, William Reed, Luisa E. Brighton, Todd M. Gambling, Albert M. Collier
    Abstract:

    Axonemal Dynein is a high molecular weight Mg2+-ATPase which occurs across the eukaryotic phylogenetic spectrum and interacts with the microtubular doublets of ciliary axonemes to effect ciliary beating. Unlike cytoplasmic Dyneins which serve intracellular functions and are relatively ubiquitous in all cells, Axonemal Dynein is expressed exclusively in mature and nascent ciliated cells. Ciliated cells figure prominently in mucociliary clearance, a primary defense mechanism of the mammalian respiratory airways. Acting in concert with mucus secreting cells, the mucociliary escalator maintains virtual sterility in the airways and lung. Although ciliated cells are the predominant cell type in the airways and serve a critical function in respiratory health, they also are particularly vulnerable to injury. The strategic functional importance of the ciliated cell as well as its susceptibility to injury by infectious agents and irritants has led to development of epithelial cell culture systems which facilitate epithelium-specific studies of injury.