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Frankel J, Buhse HE. In Memoriam: Norman E. Williams (1928-2016): Pioneer of Ciliate Architecture. J Eukaryot Microbiol 2017. [DOI: 10.1111/jeu.12395] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Joseph Frankel
- Department of Biology; The University of Iowa; Iowa City Iowa 52242
| | - Howard E. Buhse
- Department of Biological Sciences; University of Illinois at Chicago; Chicago Illinois 60607
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2
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Madey P, Melkonian M. Flagellar Development During the Cell Cycle inChlamydomonas reinhardtii. ACTA ACUST UNITED AC 2014. [DOI: 10.1111/j.1438-8677.1990.tb00133.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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3
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Broekhuis JR, Leong WY, Jansen G. Regulation of cilium length and intraflagellar transport. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2013; 303:101-38. [PMID: 23445809 DOI: 10.1016/b978-0-12-407697-6.00003-9] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Primary cilia are highly conserved sensory organelles that extend from the surface of almost all vertebrate cells. The importance of cilia is evident from their involvement in many diseases, called ciliopathies. Primary cilia contain a microtubular axoneme that is used as a railway for transport of both structural components and signaling proteins. This transport machinery is called intraflagellar transport (IFT). Cilia are dynamic organelles whose presence on the cell surface, morphology, length and function are highly regulated. It is clear that the IFT machinery plays an important role in this regulation. However, it is not clear how, for example environmental cues or cell fate decisions are relayed to modulate IFT and cilium morphology or function. This chapter presents an overview of molecules that have been shown to regulate cilium length and IFT. Several examples where signaling modulates IFT and cilium function are used to discuss the importance of these systems for the cell and for understanding of the etiology of ciliopathies.
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Wloga D, Frankel J. From Molecules to Morphology: Cellular Organization of Tetrahymena thermophila. Methods Cell Biol 2012; 109:83-140. [DOI: 10.1016/b978-0-12-385967-9.00005-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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5
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Abstract
Tubulin, the most abundant axonemal protein, is extensively modified by several highly conserved post-translational mechanisms including acetylation, detyrosination, glutamylation, and glycylation. We discuss the pathways that contribute to the assembly and maintenance of axonemal microtubules, with emphasis on the potential functions of post-translational modifications that affect tubulin. The recent identification of a number of tubulin modifying enzymes and mutational studies of modification sites on tubulin have allowed for significant functional insights. Polymeric modifications of tubulin (glutamylation and glycylation) have emerged as important determinants of the 9 + 2 axoneme assembly and motility.
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Affiliation(s)
- Jacek Gaertig
- Department of Cellular Biology, University of Georgia, Athens, Georgia, USA
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6
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Thazhath R, Jerka-Dziadosz M, Duan J, Wloga D, Gorovsky MA, Frankel J, Gaertig J. Cell context-specific effects of the beta-tubulin glycylation domain on assembly and size of microtubular organelles. Mol Biol Cell 2004; 15:4136-47. [PMID: 15254268 PMCID: PMC515347 DOI: 10.1091/mbc.e04-03-0247] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Tubulin glycylation is a posttranslational modification found in cells with cilia or flagella. The ciliate Tetrahymena has glycylation on ciliary and cortical microtubules. We showed previously that mutating three glycylation sites on beta-tubulin produces immotile 9 + 0 axonemes and inhibits cytokinesis. Here, we use an inducible glycylation domain mutation and epitope tagging to evaluate the potential of glycylation-deficient tubulin for assembly and maintenance of microtubular systems. In axonemes, the major defects, including lack of the central pair, occurred during assembly, and newly made cilia were abnormally short. The glycylation domain also was required for maintenance of the length of already assembled cilia. In contrast to the aberrant assembly of cilia, several types of cortical organelles showed an abnormally high number of microtubules in the same mutant cells. Thus, the consequences of deficiency in tubulin glycylation are organelle type specific and lead to either insufficient assembly (cilia) or excessive assembly (basal bodies and cortical microtubules). We suggest that the diverse functions of the beta-tubulin glycylation domain are executed by spatially restricted microtubule-associated proteins.
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Affiliation(s)
- Rupal Thazhath
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA
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7
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Abstract
Cilia and flagella appear to be stable, terminal, microtubule-containing organelles, but they also elongate and shorten in response to a variety of signals. To understand mechanisms that regulate flagellar dynamics, Chlamydomonas cells with nongrowing flagella were labeled with (35)S, and flagella and basal body components were examined for labeled polypeptides. Maximal incorporation of label into the flagella occurred within 3 h. Twenty percent of the flagellar polypeptides were exchanged. These included tubulins, dyneins, and 80 other axonemal and membrane plus matrix polypeptides. The most stable flagellar structure is the PF-ribbon, which comprises part of the wall of each doublet microtubule and is composed of tubulin and three other polypeptides. Most (35)S was incorporated into the high molecular weight ribbon polypeptide, rib240, and little, if any, (35)S is incorporated into PF-ribbon-associated tubulin. Both wild-type (9 + 2) and 9 + 0 flagella, which lack central microtubules, exhibited nearly identical exchange patterns, so labeling is not due to turnover of relatively labile central microtubules. To determine if flagellar length is balanced by protein exchange, (35)S incorporation into disassembling flagella was examined, as was exchange in flagella in which microtubule assembly was blocked by colchicine. Incorporation of (35)S-labeled polypeptides was found to occur into flagellar axonemes during wavelength-dependent shortening in pf18 and in fla10 cells induced to shorten flagella by incubation at 33 degrees C. Colchicine blocked tubulin addition but did not affect the exchange of the other exchangeable polypeptides; nor did it induce any change in flagellar length. Basal bodies also incorporated newly synthesized proteins. These data reveal that Chlamydomonas flagella are dynamic structures that incorporate new protein both during steady state and as flagella shorten and that protein exchange does not, alone, explain length regulation.
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Affiliation(s)
- L Song
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045, USA
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Takeda T, Yoshihama I, Numata O. Identification of Tetrahymena hsp60 as a 14-nm filament protein/citrate synthase-binding protein and its possible involvement in the oral apparatus formation. Genes Cells 2001; 6:139-49. [PMID: 11260259 DOI: 10.1046/j.1365-2443.2001.00400.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Tetrahymena 14-nm filament protein (14FP) is bifunctional, with roles as a citrate synthase in mitochondria and as a cytoskeletal protein in nuclear events during fertilization and in oral morphogenesis. In this study, to further our understanding of the bifunctional property of 14FP, we attempted to screen 14FP-binding proteins using affinity column chromatography. RESULTS Through the screening of 14FP-binding proteins using 14FP-affinity chromatography, we detected 65 kDa and 70 kDa proteins that bound to 14FP in an ATP dependent manner. From the N-terminal amino acid sequence, these proteins were identified as the Tetrahymena mitochondrial chaperones, hsp60 and mthsp70, respectively. Tetrahymena hsp60 was recognized with a monoclonal antibody raised against human hsp60. Immunofluorescence and immunoelectron microscopy using the monoclonal antibody showed that Tetrahymena hsp60 was localized to mitochondria. Moreover, Tetrahymena hsp60 was also present at extramitochondrial sites including basal bodies of cilia and oral apparatus, and particularly at the developing oral apparatus during cell division. CONCLUSION These results suggest that Tetrahymena hsp60 is localized in basal bodies and is involved in cortical patterning such as the formation of the oral apparatus as well as having a role in the folding of mitochondrial proteins in mitochondria.
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Affiliation(s)
- T Takeda
- Institute of Biological Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572 Japan
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Stephens RE. Preferential incorporation of tubulin into the junctional region of ciliary outer doublet microtubules: a model for treadmilling by lattice dislocation. CELL MOTILITY AND THE CYTOSKELETON 2000; 47:130-40. [PMID: 11013393 DOI: 10.1002/1097-0169(200010)47:2<130::aid-cm4>3.0.co;2-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Even in the presence of colchicine or Taxol(R), sea urchin embryonic cilia undergo substantial steady-state turnover, with a rate of tubulin incorporation approaching half that seen in full regeneration [Stephens: Mol Biol Cell 8:2187-2198, 1997]. Preliminary experiments suggest that tubulin incorporates differentially into the most stable portion of the outer doublet, the junctional protofilaments [Stephens: Cell Struct Funct 24:413-418, 1999]. To explore this possibility further, embryos of the sea urchin Tripneustes gratilla, a ciliary length inducible system [Stephens: J Exp Zool 269:106-115, 1994a], were pulse labeled with (3)H leucine during steady-state turnover or induced elongation, followed by regeneration in the presence of unlabeled leucine. Cilia were isolated by hypertonic shock and fractionated into detergent-soluble membrane plus matrix, thermally-solubilized microtubule walls, and insoluble 9-fold symmetric remnants of A-B junctional protofilaments plus associated architectural elements. The fractions were resolved by SDS-PAGE and the specific activity of alpha-tubulin was determined. In cilia undergoing turnover or elongation during an isotope pulse, the specific activity of tubulin in the junctional region approximated that of precursor membrane plus matrix tubulin but surpassed that of the tubule wall by a factor of approximately 1.5. In cilia regenerated during an isotope chase, the specific activity of junctional tubulin exceeded that of both the membrane plus matrix and the tubule wall by a similar factor. These data indicate that tubulin is preferentially incorporated into junctional protofilaments during steady-state turnover, induced elongation and regeneration. A model for directional incorporation based on surface lattice discontinuities in the outer doublet is proposed.
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Affiliation(s)
- R E Stephens
- Department of Physiology, Boston University School of Medicine, Boston, Massachusetts 02118, USA.
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Stephens RE, Lemieux NA. Molecular chaperones in cilia and flagella: implications for protein turnover. CELL MOTILITY AND THE CYTOSKELETON 1999; 44:274-83. [PMID: 10602256 DOI: 10.1002/(sici)1097-0169(199912)44:4<274::aid-cm5>3.0.co;2-o] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The mechanisms of protein incorporation and turnover in 9+2 ciliary axonemes are not known. Previous reports of an HSP70-related protein, first in Chlamydomonas flagella and then in sea urchin embryonic cilia, suggested a potential role in protein transport or incorporation. The present study further explores this and other chaperones in axonemes from a representative range of organisms. Two-dimensional gel electrophoresis proved identity between the sea urchin ciliary 78 kDa HSP and a constitutive cytoplasmic HSP70 cognate (pI = 5.71). When isolated flagella from mature sea urchin sperm were analyzed, the same total amount and distribution of 78 kDa protein as in cilia were found. Antigens of similar size were detected in ctenophore comb plate, molluscan gill, and rabbit tracheal cilia. Absent from sea urchin sperm flagella, TCP-1alpha was detected in sea urchin embryonic and rabbit tracheal cilia; the latter also contained HSP90, detected by two distinct antibodies. Tracheal cilia were shown to undergo axonemal protein turnover while tracheal cells mainly synthesized ciliary proteins. TCP-1alpha progressively appeared in regenerating embryonic cilia only as their growth slowed, suggesting a regulatory role in incorporation or turnover. These results demonstrate that chaperones are widely distributed ciliary and flagellar components, potentially related to axonemal protein dynamics.
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Affiliation(s)
- R E Stephens
- Department of Physiology, Boston University School of Medicine, Boston, Massachusetts 02118, USA.
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Brown JM, Marsala C, Kosoy R, Gaertig J. Kinesin-II is preferentially targeted to assembling cilia and is required for ciliogenesis and normal cytokinesis in Tetrahymena. Mol Biol Cell 1999; 10:3081-96. [PMID: 10512852 PMCID: PMC25561 DOI: 10.1091/mbc.10.10.3081] [Citation(s) in RCA: 104] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
We cloned two genes, KIN1 and KIN2, encoding kinesin-II homologues from the ciliate Tetrahymena thermophila and constructed strains lacking either KIN1 or KIN2 or both genes. Cells with a single disruption of either gene showed partly overlapping sets of defects in cell growth, motility, ciliary assembly, and thermoresistance. Deletion of both genes resulted in loss of cilia and arrests in cytokinesis. Mutant cells were unable to assemble new cilia or to maintain preexisting cilia. Double knockout cells were not viable on a standard medium but could be grown on a modified medium on which growth does not depend on phagocytosis. Double knockout cells could be rescued by transformation with a gene encoding an epitope-tagged Kin1p. In growing cells, epitope-tagged Kin1p preferentially accumulated in cilia undergoing active assembly. Kin1p was also detected in the cell body but did not show any association with the cleavage furrow. The cell division arrests observed in kinesin-II knockout cells appear to be induced by the loss of cilia and resulting cell paralysis.
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Affiliation(s)
- J M Brown
- Department of Cellular Biology, University of Georgia, Athens, Georgia 30602-2607, USA
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12
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Affiliation(s)
- J Frankel
- Department of Biological Sciences, University of Iowa, Iowa City 52242, USA
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Stephens RE. Synthesis and turnover of embryonic sea urchin ciliary proteins during selective inhibition of tubulin synthesis and assembly. Mol Biol Cell 1997; 8:2187-98. [PMID: 9362062 PMCID: PMC25701 DOI: 10.1091/mbc.8.11.2187] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/1997] [Accepted: 08/20/1997] [Indexed: 02/05/2023] Open
Abstract
When ciliogenesis first occurs in sea urchin embryos, the major building block proteins, tubulin and dynein, exist in substantial pools, but most 9 + 2 architectural proteins must be synthesized de novo. Pulse-chase labeling with [3H]leucine demonstrates that these proteins are coordinately up-regulated in response to deciliation so that regeneration ensues and the tubulin and dynein pools are replenished. Protein labeling and incorporation into already-assembled cilia is high, indicating constitutive ciliary gene expression and steady-state turnover. To determine whether either the synthesis of tubulin or the size of its available pool is coupled to the synthesis or turnover of the other 9 + 2 proteins in some feedback manner, fully-ciliated mid- or late-gastrula stage Strongylocentrotus droebachiensis embryos were pulse labeled in the presence of colchicine or taxol at concentrations that block ciliary growth. As a consequence of tubulin autoregulation mediated by increased free tubulin, no labeling of ciliary tubulin occurred in colchicine-treated embryos. However, most other proteins were labeled and incorporated into steady-state cilia at near-control levels in the presence of colchicine or taxol. With taxol, tubulin was labeled as well. An axoneme-associated 78 kDa cognate of the molecular chaperone HSP70 correlated with length during regeneration; neither colchicine nor taxol influenced the association of this protein in steady-state cilia. These data indicate that 1) ciliary protein synthesis and turnover is independent of tubulin synthesis or tubulin pool size; 2) steady-state incorporation of labeled proteins cannot be due to formation or elongation of cilia; 3) substantial tubulin exchange takes place in fully-motile cilia; and 4) chaperone presence and association in steady-state cilia is independent of background ciliogenesis, tubulin synthesis, and tubulin assembly state.
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Affiliation(s)
- R E Stephens
- Department of Physiology, Boston University School of Medicine, Massachusetts 02118, USA
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14
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Control of initiation and elongation of cilia during ciliary regeneration in Tetrahymena. Mol Cell Biol 1997. [PMID: 9279399 DOI: 10.1128/mcb.1.9.865] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Tetrahymena thermophila strain B could regenerate approximately 10% of its somatic ciliary mass in concentrations of cycloheximide believed to block all cytoplasmic protein synthesis. A quantitative study of the relative numbers and lengths of cilia regenerated in the presence and absence of cycloheximide under a variety of conditions suggested that specific initiation and elongation protein factors are involved in the control of ciliary morphogenesis in Tetrahymena.
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15
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Stephens R. Tubulin and tektin in sea urchin embryonic cilia: pathways of protein incorporation during turnover and regeneration. J Cell Sci 1994. [DOI: 10.1242/jcs.107.2.683] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Axonemal precursor tubulin is the major protein component of the detergent-soluble membrane/matrix fraction of sea urchin embryonic cilia. Its unusual abundance may reflect the rapid turnover of these cilia, a process that is further documented here. However, whether during induced regeneration or normal turnover and growth, most other newly synthesized axonemal proteins are not detectable in the membrane/matrix fraction, raising the question of how non-tubulin precursors transit the growing cilium to the distal tip where assembly is generally thought to occur. Three potential explanations were considered: (1) the assembly of these components is proximal; (2) their relative concentration is too low to detect; or (3) tubulin alone is conveyed via a membrane/matrix pathway while most other axonemal proteins are transported in association with the axoneme. Light microscope autoradiography of axonemes pulse-chase labeled with [3H]leucine showed relatively uniform labeling, with no evidence for proximal incorporation. Fully grown cilia and cilia at early stages of regeneration were isolated from labeled embryos, fractionated into membrane/matrix, axonemal tubulin and architectural remnant components, and their labeled protein compositions were compared. Heavily labeled axonemal proteins, most notably the integral microtubule doublet component tektin-A, were not detected in the membrane/matrix fraction of emerging cilia, even though nearly half of the total ciliary tubulin appeared in that fraction, arguing against membrane-associated or soluble matrix transit for the architectural proteins at low concentrations. However, after thermal fractionation of axonemes from growing cilia, labeled proteins characteristic of the architectural remnant dominated the solubilized microtubule fraction, supporting axoneme-associated transport of the non-tubulin proteins during growth, in contrast to a membrane/matrix pathway for tubulin.
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Gitz DL, Eells JB, Pennock DG. The dcc mutation affects ciliary length in Tetrahymena thermophila. J Eukaryot Microbiol 1993; 40:668-76. [PMID: 8401479 DOI: 10.1111/j.1550-7408.1993.tb06125.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
We have characterized ciliogenesis in a mutant Tetrahymena thermophila that both fails to regain motility following deciliation and that fails to complete cytokinesis. Scanning electron microscopic (SEM) observations revealed that starved deciliated cells regenerated fewer, shorter cilia at the restrictive temperature than similarly treated cells incubated at the permissive temperature. Transmission electron microscopic evaluation of isolated, regenerated cilia revealed no structural abnormalities. Incorporation of S-35 methionine was similar during ciliary regeneration at both the restrictive and permissive temperatures, indicating the mutant phenotype was not due to a simple failure in translation or transcription. Mutant cells incubated in growth medium at the restrictive temperature arrested in cytokinesis and assembled a large number of abnormally short cilia. These cells also developed irregular surface projections that were not visible on wild-type cells. These observations suggest that ciliogenesis can be initiated in growing cells as well as in starved deciliated cells but that elongation is inhibited before cilia reach full length. The mutation was named dcc for defective in ciliogenesis and cytokinesis.
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Affiliation(s)
- D L Gitz
- Department of Zoology, Miami University, Oxford, Ohio 45056
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Attwell GJ, Bricker CS, Schwandt A, Gorovsky MA, Pennock DG. A temperature-sensitive mutation affecting synthesis of outer arm dyneins in Tetrahymena thermophila. THE JOURNAL OF PROTOZOOLOGY 1992; 39:261-6. [PMID: 1533674 DOI: 10.1111/j.1550-7408.1992.tb01312.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We have characterized a novel, temperature-sensitive mutation affecting motility in Tetrahymena thermophila. Mutants grew and divided normally at the restrictive temperature (38 degrees C), but became nonmotile. Scanning electron microscopic analysis indicated that nonmotile mutants contained the normal number of cilia and that the cilia were of normal length. Transmission electron microscopic analysis indicated that axonemes isolated from nonmotile mutants lacked outer dynein arms, so the mutation was named oad 1 (outer arm deficient). Motile mutants shifted to 38 degrees C under conditions that prevent cell growth and division (starvation) remained motile suggesting that once assembled into axonemes at the permissive temperature (28 degrees C) the outer arm dyneins remain functional at 38 degrees C. Starved, deciliated mutants regenerated a full complement of functional cilia at 38 degrees C, indicating that the mechanism that incorporates the outer arm dynein into developing axonemes is not affected by the oad 1 mutation. Starved, nonmotile mutants regained motility when shifted back to 28 degrees C, but not when incubated with cycloheximide. We interpret these results to rule out the hypothesis that the oad 1 mutation affects the site on the microtubules to which the outer arm dyneins bind. Axonemes isolated from mutants grown for one generation at 38 degrees C had a mean of 6.0 outer arm dyneins, and axonemes isolated from mutants grown for two generations at 38 degrees C had a mean of 3.2 outer arm dyneins. Taken together, these results indicate that the oad 1 mutation affects the synthesis of outer arm dyneins in Tetrahymena.
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Affiliation(s)
- G J Attwell
- Department of Zoology, Miami University, Oxford, Ohio 45056
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18
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Uno S, Abé S. How is the flagellar length of mature sperm determined? II. Comparison of tubulin synthesis in spermatids between newt and Xenopus in vitro. Exp Cell Res 1990; 186:279-87. [PMID: 2298244 DOI: 10.1016/0014-4827(90)90307-v] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
In order to elucidate mechanisms that control flagellar length of mature sperm, we studied in synchronous cell suspension cultures flagellar growth, tubulin pool, and tubulin synthesis in round spermatids of Xenopus laevis and the newt Cynops pyrrhogaster. The average final length of flagella in Xenopus round spermatids was 35 mum, almost the same length as that in mature sperm, whereas in the newt round spermatids, the length was 210 mum, almost half that of mature sperm. Kinetics of flagellar growth showed that the rate and period of flagellar growth in the newt spermatids were two to threefold those in Xenopus spermatids. The tubulin pool size in newt spermatids was estimated to be about 10-fold greater than that in Xenopus spermatids. But even if all of the pool was used for flagellar growth, it could support only about a seventh to a tenth of the flagellar length in mature sperm in either species. Thus, the possibility that the tubulin pool primarily determines flagellar length was excluded. Since the tubulin pool size did not change throughout the culture period, the possibility that the termination of flagellar growth is due to the exhaustion of the tubulin pool was also excluded. Tubulin synthesis declined over the culture period but continued in newt spermatids longer than in Xenopus spermatids. The period of flagellar elongation almost coincided with the period of tubulin synthesis. The amount of rRNA did not decrease, excluding the possibility that the decline of tubulin synthesis was due to cytoplasmic shedding which might result in the loss of ribosomes. Tubulin synthesis and the amount of rRNA in newt spermatids was more than threefold greater than that in Xenopus spermatids, which may explain the difference in growth rates of their flagella.
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Affiliation(s)
- S Uno
- Department of Biology, Faculty of Science, Kumanoto University, Japan
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19
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Jauker F, Lades S, Nowack T. The energy budget of Tetrahymena and the material fluxes into and out of the adenylate pool. Exp Cell Res 1986; 166:161-70. [PMID: 3743653 DOI: 10.1016/0014-4827(86)90516-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The material budget of the adenylate pool deals with all processes which physically establish and maintain this pool, while the energy budget is concerned with the intracompartmental ATP recycling. Both budgets were analysed in Tetrahymena thermophila exposed to various energy and material demands. Some of the general conclusions are: at a maximum growth rate the overall ATP consumption during one cell cycle is 10(-10) mol ATP; the contribution of osmoregulation and ciliary motion to the budget is about 1% each; at zero net growth, energy is consumed because of a continuous recycling of matter between the monomer and the polymer compartment. The rate of ATP production is about 1000-fold greater than the rate of adenylate monomer influx. The residence time of adenylate monomers within the pool is about 30 min, but for ATP molecules it is only 2 sec.
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Seyfert HM, Sawatzki G. An estimation of the soluble tubulin content in Tetrahymena cells of normal and of size-altered phenotype. Exp Cell Res 1986; 162:86-96. [PMID: 3940232 DOI: 10.1016/0014-4827(86)90428-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The amount of soluble tubulin in a temperature-sensitive (ts) size mutant of the ciliate Tetrahymena was measured in a variety of physiological conditions. For this purpose a competitive ELISA assay for tubulin was set up. The assay is based on an antiserum against Tetrahymena axonemal tubulin. Characterization of the antiserum shows its mono-specificity towards tubulin as well as its potential to recognize tubulin from a wide variety of cellular sources and organisms. After fractionation of the cells into soluble material, cold-labile and cold-resistant structures, we found very little tubulin soluble (less than 20% of the total), while most of the tubulin is polymerized, especially into cortical structures. Prolonged starvation does not alter the tubulin content. During the culture growth cycle the percentage of the soluble tubulin increases. Growing the ts mutant at high temperature to a large cell size will also increase the pool of soluble tubulin to a large extent. Only under this condition is the amount of soluble tubulin about equal to that fixed in cilia. The tubulins in the three different compartments are polymorphic and have a different metabolism. This is indicated by the much higher specific activity of soluble tubulin compared with the structurally bound material. In agreement, the half-life of the soluble tubulin is shorter than that of the cortical tubulin.
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21
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Seyfert HM, Neufang M, Willecke R. Deciliation interferes with cell-cycle progression in Tetrahymena. Exp Cell Res 1985; 158:159-69. [PMID: 3996477 DOI: 10.1016/0014-4827(85)90440-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The impact of ciliary regeneration upon cell-cycle progression of the ciliate Tetrahymena was studied. It was found that cell division ceases during ciliary regeneration, and starts again about 4 h after deciliation. Deciliation of an asynchronously multiplying culture results in a rapid interruption of DNA synthesis, followed by resumption 1 h later. This was shown by pulse-labelling the cells with [3H]thymidine at various times after deciliation. Cytophotometric determinations of the macronuclear DNA content substantiated these observations, since the average DNA content per cell remained constant within the first hour of regeneration, confirming the labelling experiments, after which it rose. At its maximum, the average DNA content was more than doubled as compared with the beginning of the experiment. This indicates that a substantial proportion of the regenerating cells performed two rounds of DNA replication prior to cell division. The massive drop in the average DNA content during the fifth hour after deciliation indicates that the culture becomes partly synchronized for cell division by the deciliation procedure. The division synchrony results from a greater delay of the next cell division when G2 cells are deciliated than occurs in G1 cells. This was shown by deciliating cultures of Tetrahymena thermophila cells in the respective stages of the cell cycle, which had been partly synchronized by elutriator centrifugation. Thus, deciliation followed by ciliary regeneration causes a varying degree of retardation in progression through the cell cycle, being greatest for G2 cells and least for G1 cells.
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Abstract
Radioactive labeling studies demonstrate a continuous incorporation of newly synthesized proteins and glycoproteins into the intact flagella of Chlamydomonas. This apparent turnover is preferentially occurring for membrane components. In particular, two classes of flagellar membrane components, one a high molecular weight (HMW) group of closely migrating glycoproteins and the other a protein with a MW around 65 kD, are continuously turning over in the vegetative cell. This selective protein turnover may explain the ability of Chlamydomonas to rapidly recover from proteolytic modification of the flagellar surface and to change its flagellar surface properties during the early events in mating.
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Hadley GA, Williams NE. Control of initiation and elongation of cilia during ciliary regeneration in Tetrahymena. Mol Cell Biol 1981; 1:865-70. [PMID: 9279399 PMCID: PMC369370 DOI: 10.1128/mcb.1.9.865-870.1981] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Tetrahymena thermophila strain B could regenerate approximately 10% of its somatic ciliary mass in concentrations of cycloheximide believed to block all cytoplasmic protein synthesis. A quantitative study of the relative numbers and lengths of cilia regenerated in the presence and absence of cycloheximide under a variety of conditions suggested that specific initiation and elongation protein factors are involved in the control of ciliary morphogenesis in Tetrahymena.
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Affiliation(s)
- G A Hadley
- Department of Zoology, University of Iowa, Iowa City 52242, USA
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Bird RC, Zimmerman AM. Induction of tubulin synthesis during cilia regeneration in growing Tetrahymena. Exp Cell Res 1980; 128:199-205. [PMID: 6773787 DOI: 10.1016/0014-4827(80)90403-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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25
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Skriver L, Williams NE. Regeneration of cilia in starved Tetrahymena thermophila involves induced synthesis of ciliary proteins but not synthesis of membrane lipids. Biochem J 1980; 188:695-704. [PMID: 7470029 PMCID: PMC1161951 DOI: 10.1042/bj1880695] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The synthesis of ciliary-membrane phospholipids and ciliary proteins was studied after deciliation in starving Tetrahymena thermophila cells. Deciliated cells regenerated the new ciliary membrane without any induced phospholipid synthesis. The constant cell volume found during the regrowth of the cilia suggests that renewal of ciliary membranes takes place by insertion of intracellular membrane material into the cell surface. In contrast with the absence of induced phospholipid synthesis during ciliary regeneration, the synthesis of ciliary proteins was found to be induced. This enhanced synthetic activity was made possible by an increased rate of intracellular protein degradation in regenerating cells. It was found that the extent of the induced synthesis strongly depends upon the growth conditions of the cells before starvation. Furthermore, it was shown that the degree of induced protein synthesis is greater for higher-molecular-weight ciliary proteins than for lower-molecular-weight species.
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Aufderheide KJ, Frankel J, Williams NE. Formation and positioning of surface-related structures in protozoa. Microbiol Rev 1980; 44:252-302. [PMID: 6770243 PMCID: PMC373179 DOI: 10.1128/mr.44.2.252-302.1980] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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Fliss ER, Suyama Y. Tetrahymena tubulins and in vitro translation of Tetrahymena RNA. THE JOURNAL OF PROTOZOOLOGY 1979; 26:505-9. [PMID: 119852 DOI: 10.1111/j.1550-7408.1979.tb04661.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Tetrahymena outer doublet tubulin was compared with neurotubulin and Chlamydomonas flagellar tubulin on SDS-polyacrylamide gels. Tetrahymena alpha tubulin did not comigrate with either brain or flagellar alpha tubulins, although brain, flagellar, and ciliary beta tubulins all comigrated. Axonemal tubulin from Tetrahymena strain ST was compared with this tubulin from strains W, S, HSM, and E, and all were found to have the same mobilities. Poly-A containing RNA was separated from whole cell Tetrahymena RNA by oligo-dT cellulose chromatography. Poly-A+ RNA from 24-h cultures (early exponential growth) stimulated greater incorporation of amino acids into polypeptides in the wheat germ cell-free translation system than did poly-A+ RNA from 36-h and 49-h cultures. When separated on SDS-polyacrylamide gels, the translation products of the 24-h poly-A+ RNA had 2 prominent protein bands which comigrated with alpha and beta tubulin isolated from Tetrahymena cilia. These bands were not found in the translation products of poly-A+ RNA isolated from 49-h cultures or in the translation products of poly-A- RNA.
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28
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Marcaud L, Hayes D. RNA synthesis in starved deciliated Tetrahymena pyriformis. EUROPEAN JOURNAL OF BIOCHEMISTRY 1979; 98:267-73. [PMID: 111932 DOI: 10.1111/j.1432-1033.1979.tb13185.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Tetrahymena pyriformis which has been starved for 20 h by incubation in buffer, and then deciliated, can regenerate its cilia in about 90 min while still in suspension in non-nutrient medium. The process of reciliation is accompanied by protein synthesis which begins a few minutes after deciliation and by synthesis of ribosomal and messenger RNAs during a period extending from about 1 h to about 3 h after deciliation. Although net synthesis of RNA remains at a very low level until 1 h after deciliation, a qualitative change in the translatable poly(A)-containing messenger RNA content of deciliated cells, and in particular, formation of beta-tubulin mRNA can be detected almost immediately after deciliation.
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Portier MM, Milet M, Hayes DH. Translation in vitro of Tetrahymena pyriformis polyadenylated mRNA. Identification of tubulin amongst the translated products and demonstration of its heterogeneity. EUROPEAN JOURNAL OF BIOCHEMISTRY 1979; 97:161-8. [PMID: 113212 DOI: 10.1111/j.1432-1033.1979.tb13098.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The capacity of poly(A)-containing RNA of the protozoan ciliate Tetrahymena pyriformis to direct the synthesis of proteins in vitro has been tested using two cell-free systems: a wheat germ extract and a rabbit reticulocyte lysate. The results obtained with these two systems are compared and the identification of alpha and beta tubulins among the products of protein synthesis in vitro, after separation by one-dimensional and two-dimensional electrophoresis, is described. By isoelectric focusing in polyacrylamide gels, each species of tubulin is resolved into several bands, suggesting that the main subunits are more heterogeneous than has been generally described. Poly(A)-containing RNA has also been fractionated on a 70% formamide/sucrose gradient and it is shown that alpha and beta tubulins are coded by separate mRNAs.
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Brown DL, Rogers KA. Hydrostatic pressure-induced internalization of flagellar axonemes, disassembly, and reutilization during flagellar regeneration in Polytomella. Exp Cell Res 1978; 117:313-24. [PMID: 720414 DOI: 10.1016/0014-4827(78)90145-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Nelsen EM, Debault LE. Transformation in Tetrahymena pyriformis: description of an inducible phenotype. THE JOURNAL OF PROTOZOOLOGY 1978; 25:113-9. [PMID: 96253 DOI: 10.1111/j.1550-7408.1978.tb03880.x] [Citation(s) in RCA: 66] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Transformation of Tetrahymena pyriformis to a rapid-swimming (presumably dispersal) form can be induced by washing cells and suspending them in distilled H2O, Dryl's solution or 10 mM Tris. Transformation is possible with high efficiency in mass cultures of axenically grown cells within approximately 5 h at 30 C. The radically different phenotype produced during transformation is characterized by a more elongate body form, increased numbers of somatic basal bodies and cilia, a long caudal cilium and oral membranelles positioned beneath the cell surface. DNA quantities characteristic of G1, S, and G2 cells are found in these transformed ciliates, suggesting that achievement of a particular stage in the DNA-division cycle is not a prerequisite for transformation. Preliminary observations on cells belonging to syngens 2-12 indicate that they also have a capacity to form a caudal cilium, but that the amicronucleate strain GL-C does not. Possible relevance of the transformed phenotype for taxonomy of Tetrahymena is discussed.
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Frankel J, Nelsen EM, Jenkins LM. Mutations affecting cell division in Tetrahymena pyriformis, syngen 1. II. Phenotypes of single and double homozygotes. Dev Biol 1977; 58:255-75. [PMID: 407114 DOI: 10.1016/0012-1606(77)90091-4] [Citation(s) in RCA: 37] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Weeks DP, Collis PS. Induction of microtubule protein synthesis in Chlamydomonas reinhardi during flagellar regeneration. Cell 1976; 9:15-27. [PMID: 975238 DOI: 10.1016/0092-8674(76)90048-9] [Citation(s) in RCA: 89] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Flagellar regeneration in gametes of Chlamydomonas reinhardi is initiated within 15-20 min after flagellar amputation and proceeds at a rapid but decelerating rate until by 90 min flagellar outgrowth in 80-85% complete. Sufficient flagellar protein reserves exist in the cytoplasm to allow regeneration of flagella 1/3-1/2 normal length. Nevertheless, in vivo labeling with 14C-amino acids shows that microtubule protein and other flagellar proteins are synthesized de novo during flagellar regeneration. To determine whether tubulin is synthesized continuously by gametic cells or whether its synthesis is induced as a consequence of deflagellation, we have isolated polyribosomes from deflagellated and control cells, and analyzed the proteins produced by these polyribosomes during in vitro translation. Two proteins of 53,000 and 56,000 molecular weight which co-migrate with flagellar and chick brain tubulin on SDS-polyacrylamide gels and which selectively co-assemble with chick brain tubulin during in vitro microtubule assembly are synthesized by polyribosomes (or polyadenylated mRNA) from deflagellated cells. No microtubule proteins can be detected in the translation products synthesized by polyribosomes (or mRNA) from control cells, clearly indicating that deflagellation results in the induction ot tubulin synthesis. Kinetics of tubulin synthesis demonstrate that induction takes place immediately after deflagellation; polyribosomes bearing tubulin mRNA can be detected in the cytoplasm in as little as 15 min after removal of flagella. Maximal rates of tubulin synthesis occur between 45 and 90 min after deflagellation when approximately 14% of the protein being synthesized by the cell is tubulin. This estimate of tubulin synthesis based on in vitro translation data agrees well with in vivo measurements of flagellar tubulin synthesis. While high levels of tubulin production extend well beyond the period of rapid flagellar assembly, synthesis begins to decline after 90 min, and by 180 min after deflagellation only low levels of tubulin mRNA are detectable in polyribosomes.
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