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At least 19 recordsLinked to original sources
PubMed1993

Stabilization of microtubules by dynein-binding in vitro. Stability of microtubule-dynein complex.

We have studied the effects of dynein binding on the stability of microtubules in vitro, using Tetrahymena ciliary dynein and microtubules (three-cycled purified microtubules: 3 X-Mts and phosphocellulose-column purified microtubules: PC-Mts). To determine the relative stability of the microtubules, we first prepared the microtubules bound with dynein (Mts--dynein complex) and subjected the Mts-dynein complex to treatments that depolymerize the microtubules, such as dilution to below critical concentration of tubulin, calcium ions and lower temperature. Dark-field microscopy revealed that the microtubules in the Mts--dynein complex appeared intact under conditions which otherwise result in microtubule depolymerization. However, when dynein was dissociated from the Mts--dynein complex with addition of ATP, no microtubule was found in the specimens under the same conditions. That is, the microtubules in the Mts--dynein complex did not depolymerize upon dilution with the buffer solution to below critical concentration of tubulin. However, addition of ATP to the diluted specimen caused dynein to become separated from the Mts, resulting in complete depolymerization of the microtubules. Stability of the microtubules was also studied by the turbidity changes and was confirmed by the patterns of stained gel bands in electrophoresis. With the addition of calcium ion, the Mts--dynein complex decomposed into separate molecules dynein and tubulin. At the lower temperature of 0 degrees C, the 3 X-Mts--dynein complex was decomposed into dynein and tubulin, while the microtubules in the PC-Mts--dynein complex did not depolymerize. Although we have not yet studied the effects of cytoplasmic dynein binding on the microtubules, the results suggest that the stabilizing effect of dynein binding to the microtubules is one of the important functions of dynein in vivo.

Animals↗
PubMed1997

Identification of dynein heavy chain genes expressed in human and mouse testis: chromosomal localization of an axonemal dynein gene.

Dynein heavy chains are involved in microtubule-dependent transport processes. While cytoplasmic dyneins are involved in chromosome or vesicle movement, axonemal dyneins are essential for motility of cilia and flagella. Here we report the isolation of dynein heavy chain (DHC)-like sequences in man and mouse. Using polymerase chain reaction and reverse-transcribed human and mouse testis RNA cDNA fragments encoding the conserved ATP binding region of dynein heavy chains were amplified. We identified 11 different mouse and eight human dynein-like sequences in testis which show high similarity to known dyneins of different species such as rat, sea urchin or green algae. Sequence similarities suggest that two of the mouse clones and one human clone encode putative cytoplasmic dynein heavy chains, whereas the other sequences show higher similarity to axonemal dyneins. Two of nine axonemal dynein isoforms identified in the mouse testis are more closely related to known outer arm dyneins, while seven clones seem to belong to the inner arm dynein group. Of the isolated human isoforms three clones were classified as outer arm and four clones as inner arm dynein heavy chains. Each of the DHC cDNAs corresponds to an individual gene as determined by Southern blot experiments. The alignment of the deduced protein sequences between human (HDHC) and mouse (MDHC) dynein fragments reveals higher similarity between single human and mouse sequences than between two sequences of the same species. Human and mouse cDNA fragments were used to isolate genomic clones. Two of these clones, gHDHC7 and gMDHC7, are homologous genes encoding axonemal inner arm dyneins. While the human clone is assigned to 3p21, the mouse gene maps to chromosome 14.

Amino Acid Sequence↗
PubMed1977

Immunological relation between 14 S dynein and 30 S dynein from the cilia of Tetrahymena pyriformis.

The immunological relation between 14 S dynein and 30 S dynein obtained from Tetrahymena cilia was investigated by using antisera specific for each dynein subunit or some dynein subunits separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Although 14 and 30 S dynein main subunits have different electrophoretic mobilities, our immunodiffusion tests showed that there exists a close immunological relation between them. At least three immunologically different polypeptides designated polypeptides A, B and C are included in the 30 S dynein main band which has been recognized as a single component by electrophoresis, and that the polypeptides designated A',B' and C' are included in the 14 S dynein main bands. Polypeptides A and A',B and B', or C and C' appeared to have a certain common antigenic determinant(s). Polypeptide C of 30 S dynein was shown to possess a certain antigenic determinant(s) specific for 30 S dynein, besides the determinant common with that of polypeptide C' of 14S dynein. The second main component of 30 S dynein proved to be a specific polypeptide of 30 S dynein but not to be a degraded product of the main polypedtide. All antisera reacted with native dynein molecules to some extent, but did not inhibit dynein ATPase (ATP phosphohydrase, EC 3.6.1.3) activity significantly.

Adenosine Triphosphatases↗
PubMed1999

Computer simulation of flagellar movement: VII. Conventional but functionally different cross-bridge models for inner and outer arm dyneins can explain the effects of outer arm dynein removal.

Outer arm dynein removal from flagella by genetic or chemical methods causes decreased frequency and power, but little change in bending pattern. These results suggest that outer arm dynein operates within bends to increase the speed of bend propagation, but does not produce forces that alter the bending pattern established by inner arm dyneins. A flagellar model incorporating different cross-bridge models for inner and outer arm dyneins has been examined. The inner arm dynein model has a hyperbolic force-velocity curve, with a maximum average force at 0 sliding velocity of about 14 pN for each 96 nm group of inner arm dyneins. The outer arm dynein model has a very different force-velocity curve, with a maximum force at about 10-15% of V(max). The outer arm dynein model is adjusted so that the unloaded sliding velocity for a realistic mixture of inner and outer arm dyneins is twice the unloaded sliding velocity for the inner arm dynein model alone. With these cross-bridge models, a flagellar model can be obtained that reduces its sliding velocity and frequency by approximately 50% when outer arm dyneins are removed, with little change in bending pattern. The addition of outer arm dyneins, therefore, gives an approximately 4-fold increase in power output against viscous resistances, and outer arm dyneins may generate 90% or more of the power output. Cell Motil.

Animals↗
PubMed1986

An antiserum to the sea urchin 20 S egg dynein reacts with embryonic ciliary dynein but it does not react with the mitotic apparatus.

Unfertilized sea urchin eggs contain one or more dynein-like enzymes which may be able to serve as microtubule translocators during embryonic development. There are at least two interesting possibilities for the function of the egg dynein: the enzyme may be involved in cytoplasmic microtubule movement such as mitotic spindle anaphase motion; or the enzyme may be a stored precursor for the dynein that functions in embryonic cilia, which are expressed and highly motile at the blastula stage of development. In order to determine directly the distribution and possible function of one of the previously described egg dyneins, the latent-activity 20 S egg dynein (Asai and Wilson, 1985), an antiserum was produced which was highly reactive with the important high Mr polypeptides of 20 S dynein. This antiserum reacted in "Western" immunoblots and in dot-blotting experiments with egg dynein and with embryonic ciliary dynein, but it did not react with any component of sperm flagella. Indirect double immunofluorescence microscopy demonstrated that the anti-20 S antiserum could brightly stain embryonic cilia but it did not stain the sperm flagella from the same sea urchin species. Under the same conditions that the antiserum stained cilia, anti-20 S did not stain the mitotic apparatus but it did appear to stain the cortical region of the dividing egg. In a time-course experiment, the antigen reactive with the anti-20 S antiserum gradually accumulated in the developing early sea urchin embryo. The most significant increase in the apparent concentration of the 20 S dynein occurred just prior to embryonic ciliation and during a period when the mitotic activity of the embryo was in decline. These results lead to two conclusions. First, ciliary dynein and sperm flagellar dynein, although derived from very similar organelles and from the same species of sea urchin, are immunologically distinct. Second, the 20 S egg dynein may be a stored precursor of embryonic ciliary dynein and does not appear to be a component of the mitotic apparatus.

Adenosine Triphosphatases↗
PubMed1985

Rebinding of Tetrahymena 13 S and 21 S dynein ATPases to extracted doublet microtubules. The inner row and outer row dynein arms.

Ciliary axonemes from Tetrahymena contain a second salt-extractable ATPase distinguishable from outer arm 21 S dynein by sedimentation velocity (congruent to 13 S), electrophoretic mobility and substrate specificity. As characterized by turbidimetric assay, gel electrophoresis in the presence of sodium dodecyl sulphate, ATPase activity and electron microscopy, the 13 S dynein ATPase rebinds to extracted doublet microtubules. Compared to structural-side (ATP-insensitive) 21 S dynein binding, which is moderately specific for the 24 nm outer row arm position, rebinding of 13 S dynein is highly specific but for the inner row arm position. However, 13 S dynein rebinds to the A subfibre with a spacing that coincides with the triplet spacing of the radial spokes (24-32-40 nm periods; 96 nm repeat). All of the major protein components present in the 13 S or 21 S fractions rebind to extracted doublets under conditions that both restore and activate dynein ATPase activity. Unlike active-side (ATP-sensitive) rebound 21 S dynein, rebound 13 S dynein is completely insensitive to dissociation by ATP-vanadate and does not independently decorate the B subfibre. The saturation profile for rebinding of 13 S dynein exhibits a lack of cooperativity between binding events (h = 1.0) similar to structural-side rebinding of 21 S dynein. At low 21 S/doublet stoichiometry there is no measureable competition between the 13 S and 21 S dyneins for binding sites on the A subfibre lattice, although at saturating concentrations of 21 S dynein, rebinding of 13 S dynein is blocked completely.

Adenosine Triphosphatases↗
PubMed2003

The third P-loop domain in cytoplasmic dynein heavy chain is essential for dynein motor function and ATP-sensitive microtubule binding.

Sequence comparisons and structural analyses show that the dynein heavy chain motor subunit is related to the AAA family of chaperone-like ATPases. The core structure of the dynein motor unit derives from the assembly of six AAA domains into a hexameric ring. In dynein, the first four AAA domains contain consensus nucleotide triphosphate-binding motifs, or P-loops. The recent structural models of dynein heavy chain have fostered the hypothesis that the energy derived from hydrolysis at P-loop 1 acts through adjacent P-loop domains to effect changes in the attachment state of the microtubule-binding domain. However, to date, the functional significance of the P-loop domains adjacent to the ATP hydrolytic site has not been demonstrated. Our results provide a mutational analysis of P-loop function within the first and third AAA domains of the Drosophila cytoplasmic dynein heavy chain. Here we report the first evidence that P-loop-3 function is essential for dynein function. Significantly, our results further show that P-loop-3 function is required for the ATP-induced release of the dynein complex from microtubules. Mutation of P-loop-3 blocks ATP-mediated release of dynein from microtubules, but does not appear to block ATP binding and hydrolysis at P-loop 1. Combined with the recent recognition that dynein belongs to the family of AAA ATPases, the observations support current models in which the multiple AAA domains of the dynein heavy chain interact to support the translocation of the dynein motor down the microtubule lattice.

Adenosine Triphosphate↗
PubMed1985

Alloaffinity filtration: a general approach to the purification of dynein and dynein-like molecules.

Alloaffinity filtration simply and specifically separates certain axonemal dyneins and dynein arm components from crude mixtures on the basis of their ability to bind and decorate Tetrahymena axonemal microtubules on a filter in the absence of ATP and to detach and pass into the eluate when 0.5 mM ATP is added. The procedure, which may be performed repetitively, is successful in purifying a Tetrahymena dynein that has characteristics of 30 S dynein prepared by conventional methods, while other dyneins originally present in the mixture, e.g., 14 S Tetrahymena dynein, are not found in the ATP eluate. A relatively homogeneous population of dynein oligomers is obtained. Alloaffinity-purified 30 S Tetrahymena dynein consists of heavy-, intermediate-, and light-chain polypeptides that cosediment in a sucrose gradient in fixed molar ratios and that have structural features of in situ Tetrahymena arms. Dyneins from other species will bind to Tetrahymena microtubules and can be purified by this method. Alloaffinity-purified Chlamydomonas dynein is a set of polypeptides including the four heavy chains that characterize the outer arm.

Adenosine Triphosphatases↗
PubMed1996

Inner dynein arms but not outer dynein arms require the activity of kinesin homologue protein KHP1(FLA10) to reach the distal part of flagella in Chlamydomonas.

Inner dynein arms, but not outer dynein arms, require the activity of KHP1(FLA10) to reach the distal part of axonemes before binding to outer doublet microtubules. We have analyzed the rescue of inner or outer dynein arms in quadriflagellate dikaryons by immunofluorescence microscopy of p28(IDA4), an inner dynein arm light chain, or IC69(ODA6), an outer dynein arm intermediate chain. In dikaryons two strains with different genetic backgrounds share the cytoplasm. As a consequence, wild-type axonemal precursors are transported to and assembled in mutant axonemes to complement the defects. The rescue of inner dynein arms containing p28 in ida4-wild-type dikaryons progressively occurred from the distal part of the axonemes and with time was extended towards the proximal part. In contrast, the rescue of outer dynein arms in oda2-wild-type dikaryons progressively occurred along the entire length of the axoneme. Rescue of inner dynein arms containing p28 in ida4fla10-fla10 dikaryons was similar to the rescue observed in ida4-wild-type dikaryons at 21 degrees C, whereas it was inhibited at 32 degrees C, a nonpermissive temperature for KHP1(FLA10). In contrast, rescue of outer dynein arms in oda2fla10-fla10 dikaryons was similar to the rescue observed in oda2-wild-type dikaryons at both 21 degrees and 32 degrees C and was not inhibited at 32 degrees C. Positioning of substructures in the internal part of the axonemal shaft requires the activity of kinesin homologue protein 1.

Algal Proteins↗
PubMedDate not supplied

Analyses of 22S dynein binding to Tetrahymena axonemes lacking outer dynein arms.

Tetrahymena thermophila mutants homozygous for the oad mutation become nonmotile when grown at the restrictive temperature of 39 degrees C. Axonemes isolated from nonmotile oad mutants (oad 39 degrees C axonemes) lack approximately 90% of their outer dynein arms and are deficient in 22S dynein. Here we report that oad 39 degrees C axonemes contain 40% of the 22S dynein heavy chains that wild-type axonemes contain and that oad axonemes do not undergo ATP-induced microtubule sliding in vitro. Wild-type 22S dynein will bind to the outer arm position in oad axonemes and restore ATP-induced microtubule sliding in those axonemes. Unlike wild-type 22S dynein, oad 22S dynein does not bind to the outer arm position in oad axonemes. These data indicate that the oad mutation affects some component of the outer arm dynein itself rather than the outer arm dynein binding site. These data also indicate that oad axonemes can be used to assay outer dynein arm function.

Adenosine Triphosphate↗
PubMed1995

Extrusion of rotating microtubules on the dynein-track from a microtubule-dynein gamma-complex.

Applying a new in vitro motility assay system for microtubules and 22S dynein, we recently reported on an ATP-induced extrusion of microtubules from microtubule-dynein alpha- and beta-complexes [Mimori and Miki-Noumura, 1994: Cell Motil. Cytoskeleton 27:180-191]. In the present study, we prepared a gamma-complex by copolymerizing porcine brain tubulin and Tetrahymena ciliary 22S dynein, and examined the ATP-induced microtubule movement from the gamma-complex. The extrusion process appeared quite similar to that of the beta-complex. The sliding velocity was 18.39 +/- 2.20 microns/sec, which was a value comparable to that of trypsin-digested flagellar axonemes [Yano and Miki-Noumura, 1980: J. Cell Sci. 44:169-186]. Higher velocity may be due to a densely arranged dynein-track with the same polarity, which was detached from the gamma-complex and absorbed in rows on a glass surface of the slide. Sometimes a free-floating microtubule in the perfusion chamber was observed riding and sliding on the dynein-track remaining on the slide after extrusion. Unexpectedly, we found that when the front part of the microtubule was fixed to a glass surface, a continuous sliding microtubule at the rear part on the dynein-track often transformed into a left-handed helix, and subsequently a twisted helix with several turns. The helix formation may be due to some rigidity in the microtubule and a right-handed torque component in the sliding force of 22S dynein. The addition of ATP may release some distortion accumulated in the complex structure during copolymerization of tubulin and 22S dynein, inducing reverse rotation of the microtubule.

Adenosine Triphosphate↗
PubMed2005

An axonemal dynein particularly important for flagellar movement at high viscosity. Implications from a new Chlamydomonas mutant deficient in the dynein heavy chain gene DHC9.

Ciliary and flagellar axonemes contain multiple inner arm dyneins of which the functional difference is largely unknown. In this study, a Chlamydomonas mutant, ida9, lacking inner arm dynein c was isolated and shown to carry a mutation in the DHC9 dynein heavy chain gene. The cDNA sequence of DHC9 was determined, and its information was used to show that >80% of it is lost in the mutant. Electron microscopy and image analysis showed that the ida9 axoneme lacked electron density near the base of the S2 radial spoke, indicating that dynein c localizes to this site. The mutant ida9 swam only slightly slower than the wild type in normal media. However, swimming velocity was greatly reduced when medium viscosity was modestly increased. Thus, dynein c in wild type axonemes must produce a significant force when flagella are beating in viscous media. Because motility analyses in vitro have shown that dynein c is the fastest among all the inner arm dyneins, we can regard this dynein as a fast yet powerful motor.

Amino Acid Sequence↗
PubMed1987

Chymotryptic digestion of Tetrahymena 22S dynein. I. Decomposition of three-headed 22S dynein to one- and two-headed particles.

Molecular composition of Tetrahymena ciliary dynein has been examined by electron microscopy and gel electrophoresis. SDS-urea gel electrophoresis revealed that Tetrahymena 22S dynein contains three (A alpha, A beta, and A gamma) heavy chains whereas 14S dynein contains only one. The molecular masses of 22S and 14S dynein heavy chains were estimated to be approximately 490 and 460 kD, respectively. Electron microscopy of negatively stained specimens showed 22S dynein has three globular heads and thin stalks, whereas 14S dynein consists of a single head. Chymotrypsin digested each of the three 22S dynein heavy chains into large fragments with different time courses. Sucrose density gradient centrifugation separated the digestion products as two peaks. The one with a larger sedimentation coefficient mainly consisted of two-headed particles having binding ability to doublet microtubules, whereas the other with a smaller sedimentation coefficient consisted of only isolated globular particles. Both fractions had ATPase activities. Thus, one active head of 22S dynein can be isolated by chymotrypsin digestion.

Adenosine Triphosphatases↗
PubMed2001

Apoptotic cleavage of cytoplasmic dynein intermediate chain and p150(Glued) stops dynein-dependent membrane motility.

Cytoplasmic dynein is the major minus end-directed microtubule motor in animal cells, and associates with many of its cargoes in conjunction with the dynactin complex. Interaction between cytoplasmic dynein and dynactin is mediated by the binding of cytoplasmic dynein intermediate chains (CD-IC) to the dynactin subunit, p150(Glued). We have found that both CD-IC and p150(Glued) are cleaved by caspases during apoptosis in cultured mammalian cells and in Xenopus egg extracts. Xenopus CD-IC is rapidly cleaved at a conserved aspartic acid residue adjacent to its NH(2)-terminal p150(Glued) binding domain, resulting in loss of the otherwise intact cytoplasmic dynein complex from membranes. Cleavage of CD-IC and p150(Glued) in apoptotic Xenopus egg extracts causes the cessation of cytoplasmic dynein--driven endoplasmic reticulum movement. Motility of apoptotic membranes is restored by recruitment of intact cytoplasmic dynein and dynactin from control cytosol, or from apoptotic cytosol supplemented with purified cytoplasmic dynein--dynactin, demonstrating the dynamic nature of the association of cytoplasmic dynein and dynactin with their membrane cargo.

Amino Acid Sequence↗
PubMed2005

Dynein light chain rp3 acts as a nuclear matrix-associated transcriptional modulator in a dynein-independent pathway.

Cytoplasmic dynein is a motor protein complex involved in microtubule-based cargo movement. Previous biochemical evidence suggests that dynein light chain subunits also exist outside the dynein complex. Here we show that the dynein light chain rp3 is present in both the cytoplasm and the nucleus. Nuclear rp3 binds to and assembles with the transcription factor SATB1 at nuclear matrix-associated structures. Dynein intermediate chain was also detected in the nucleus, but it was dispensable for the rp3-SATB1 interaction. SATB1 facilitates the nuclear localization of rp3, whereas rp3 and dynein motor activity are not essential for nuclear accumulation of SATB1. The nuclear rp3-SATB1 protein complex is assembled with a DNA element of the matrix attachment region of the Bcl2 gene. Finally, rp3 is involved in SATB1-mediated gene repression of Bcl2. Our data provide evidence that dynein subunit rp3 has functions independent of the dynein motor.

Cell Line↗
PubMed1998

The 29 kDa light chain that regulates axonemal dynein activity binds to cytoplasmic dyneins.

In earlier studies, Hamasaki et al. (Proc. Natl. Acad. Sci. USA. 88:7918-7922, 1991) and Barkalow et al. (J. Cell Biol. 126:727-735, 1994) found that cAMP- and Ca2+-sensitive phosphorylation of a 29 kDa dynein light chain (p29) extracted from 22S axonemal dynein of Paramecium, regulates the velocity of in vitro microtubule translocation and ciliate swimming speed. In this study we report evidence of recombination of p29 to cytoplasmic dyneins from both rat liver and Paramecium, as well as to a 22S dynein precursor molecule, based on immunoprecipitation and force filtration data. Immunoprecipitation also provides additional evidence for the binding of p29 to 22S axonemal dynein. The results suggest that p29 might regulate cytoplasmic dynein, as well as axonemal dynein function in Paramecium, and that a homologue of p29 may exist in rat liver and other mammalian cells.

Animals↗
PubMed1998

Dynein and dynein-related genes.

Dyneins are large, multisubunit ATPases that interact with microtubules to generate force. Dyneins move eukaryotic cilia and flagella and are in the cytoplasm, where they are involved in the transport of particles and organelles along microtubules and in the transport of condensed chromosomes during mitosis [reviewed in Holzbaur et al., 1994; Gibbons, 1996]. Defects in human axonemal dynein complexes have been shown to be associated with Kartagener's syndrome, which is characterized by recurrent respiratory tract infections, immotile sperm and situs inversus. Cytoplasmic and axonemal dyneins are composed of heavy, intermediate, and light chains. The best characterised groups of dynein genes so far are those encoding cytoplasmic heavy chains and heavy chains from the outer arms from axonemes. These share extensive sequence similarity and are conserved throughout species. Recently, several genes encoding intermediate and light chains have been identified; these have encoded a remarkable diversity of products, which also seem to be highly conserved between species, although they fall into several complex groups. The structure of dynein heavy chain genes, the emerging knowledge on intermediate and light chain genes and their products, and the possible involvement of dyneins in disease are discussed.

Amino Acid Sequence↗
PubMed1984

Structural comparison of purified dynein proteins with in situ dynein arms.

Using the quick-freeze deep-etch technique, we describe the structure of outerarm dynein proteins from Chlamydomonas and Tetrahymena after adsorption to a mica surface, after high-salt dissociation, and after glutaraldehyde fixation, and compare these images to the configuration of outer arms bound to microtubules. After adsorption to mica, the extracted dyneins from both organisms look like three-headed "bouquets", as reported for Tetrahymena by Johnson & Wall (1983b). High magnification images demonstrate that each head carries a slender "stalk" and a long "stem", and that small subunits decorate the stems and create a "flowerpot" domain at the base of the bouquet. Exposure to high salt induces this trimer to dissociate into a two-headed species and a single-headed species; it also stimulates the decorative elements to dissociate from the stems. Dynein is thus constructed on the same general plan as myosin, with large globular heads, narrow stems and additional small subunits that associate with the stems. The splayed-out image of the bouquet appears to be a distortion arising during adsorption to mica since, after brief glutaraldehyde fixation, the three heads remain closely associated as vertices of a triangular unit. In situ, the three heads also adopt this trigonal configuration. Two of the three are visible from the exterior of the axoneme and constitute the bilobed rigor head we described previously (Goodenough & Heuser, 1982). The third head faces the interior of the axoneme where, we propose, it forms the "hook" of the outer arm as seen in thin section. We further propose that the decorative elements associated with the stem coalesce to form the two outer-arm "feet" seen in situ, and that at least one of the in vitro stalks is equivalent to the in situ stalk, which extends from the head to the B microtubule. Deep-etch images of stretched axonemes, partially extracted axonemes, and dynein-decorated brain microtubules indicate that each outer arm, as traditionally viewed, is a hybrid of two dynein molecules: its two feet derive from one molecule, whereas its trigonal head derives from the molecule located distally. The resultant overlapping configuration creates the diagonal "linkers" seen in situ, which correspond to the in vitro stems. Thus, a row of dynein arms is essentially a dynein polymer that extends from the tip to the base of a doublet microtubule, each head riding on its neighbor's feet like a row of circus elephants.(ABSTRACT TRUNCATED AT 400 WORDS)

Adenosine Triphosphatases↗