scholarly journals A monoclonal antibody against the dynein IC1 peptide of sea urchin spermatozoa inhibits the motility of sea urchin, dinoflagellate, and human flagellar axonemes.

1994 ◽  
Vol 5 (9) ◽  
pp. 1051-1063 ◽  
Author(s):  
C Gagnon ◽  
D White ◽  
P Huitorel ◽  
J Cosson

To investigate the role of axonemal components in the mechanics and regulation of flagellar movement, we have generated a series of monoclonal antibodies (mAb) against sea urchin (Lytechinus pictus) sperm axonemal proteins, selected for their ability to inhibit the motility of demembranated sperm models. One of these antibodies, mAb D1, recognizes an antigen of 142 kDa on blots of sea urchin axonemal proteins and of purified outer arm dynein, suggesting that it acts by binding to the heaviest intermediate chain (IC1) of the dynein arm. mAb D1 blocks the motility of demembranated sea urchin spermatozoa by modifying the beating amplitude and shear angle without affecting the ATPase activity of purified dynein or of demembranated immotile spermatozoa. Furthermore, mAb D1 had only a marginal effect on the velocity of sliding microtubules in trypsin-treated axonemes. This antibody was also capable of inhibiting the motility of flagella of Oxyrrhis marina, a primitive dinoflagellate, and those of demembranated human spermatozoa. Localization of the antigen recognized by mAb D1 by immunofluorescence reveals its presence on the axonemes of flagella from sea urchin spermatozoa and O. marina but not on the cortical microtubule network of the dinoflagellate. These results are consistent with a dynamic role for the dynein intermediate chain IC1 in the bending and/or wave propagation of flagellar axonemes.

1996 ◽  
Vol 109 (6) ◽  
pp. 1545-1553 ◽  
Author(s):  
C. Gagnon ◽  
D. White ◽  
J. Cosson ◽  
P. Huitorel ◽  
B. Edde ◽  
...  

To investigate whether a specific isotype of tubulin is involved in flagellar motility, we have developed and screened a panel of monoclonal antibodies (mAb) generated against sea urchin sperm axonemal proteins. Antibodies were selected for their ability to block the motility of permeabilized sperm models. The antitubulin mAb B3 completely inhibited, at low concentrations, the flagellar motility of permeabilized sperm models from four sea urchin species. On immunoblots, B3 recognized predominantly alpha-tubulin in sea urchin sperm axonemes and equally well brain alpha- and beta-tubulins. Subtilisin cleavage of tubulin removed the B3 epitope, indicating that it was restricted to the last 13 amino acid residues of the C-terminal domain of alpha-tubulin. In enzyme-linked immunosorbant assays, B3 reacted with glutamylated alpha-tubulin peptides from sea urchin or mouse brain but did not bind to the unmodified corresponding peptide, indicating that it recognized polyglutamylated motifs in the C-terminal domain of alpha-tubulin. On the other hand, other tubulin antibodies directed against various epitopes of the C-terminal domain, with the exception of the antipolyglutamylated mAb GT335, had no effect on motility while having binding properties similar to that of B3. B3 and GT335 acted by decreasing the beating amplitude without affecting the flagellar beat frequency. B3 and GT335 were also capable of inhibiting the motility of flagella of Oxyrrhis marina, a 400,000,000 year old species of dinoflagellate, and those of human sperm models. Localization of the antigens recognized by B3 and GT335 by immunofluorescence techniques revealed their presence along the whole axoneme of sea urchin spermatozoa and flagella of O. marina, except for the distal tip and the cortical microtubule network of the dinoflagellate. Taken together, the data reported here indicate that the polyglutamylated lateral chain of alpha-tubulin plays a dynamic role in a dynein-based motility process.


Development ◽  
1995 ◽  
Vol 121 (5) ◽  
pp. 1497-1505 ◽  
Author(s):  
A.H. Wikramanayake ◽  
B.P. Brandhorst ◽  
W.H. Klein

During early embryogenesis, the highly regulative sea urchin embryo relies extensively on cell-cell interactions for cellular specification. Here, the role of cellular interactions in the temporal and spatial expression of markers for oral and aboral ectoderm in Strongylocentrotus purpuratus and Lytechinus pictus was investigated. When pairs of mesomeres or animal caps, which are fated to give rise to ectoderm, were isolated and cultured they developed into ciliated embryoids that were morphologically polarized. In animal explants from S. purpuratus, the aboral ectoderm-specific Spec1 gene was activated at the same time as in control embryos and at relatively high levels. The Spec1 protein was restricted to the squamous epithelial cells in the embryoids suggesting that an oral-aboral axis formed and aboral ectoderm differentiation occurred correctly. However, the Ecto V protein, a marker for oral ectoderm differentiation, was detected throughout the embryoid and no stomodeum or ciliary band formed. These results indicated that animal explants from S. purpuratus were autonomous in their ability to form an oral-aboral axis and to differentiate aboral ectoderm, but other aspects of ectoderm differentiation require interaction with vegetal blastomeres. In contrast to S. purpuratus, aboral ectoderm-specific genes were not expressed in animal explants from L. pictus even though the resulting embryoids were morphologically very similar to those of S. purpuratus. Recombination of the explants with vegetal blastomeres or exposure to the vegetalizing agent LiCl restored activity of aboral ectoderm-specific genes, suggesting the requirement of a vegetal induction for differentiation of aboral ectoderm cells.(ABSTRACT TRUNCATED AT 250 WORDS)


Development ◽  
1988 ◽  
Vol 103 (2) ◽  
pp. 317-324 ◽  
Author(s):  
J. Hardin

It has long been thought that traction exerted by filopodia of secondary mesenchyme cells (SMCs) is a sufficient mechanism to account for elongation of the archenteron during sea urchin gastrulation. The filopodial traction hypothesis has been directly tested here by laser ablation of SMCs in gastrulae of the sea urchin, Lytechinus pictus. When SMCs are ablated at the onset of secondary invagination, the archenteron doubles in length at the normal rate of elongation, but advance of the tip of the archenteron stops at the 2/3 gastrula stage. In contrast, when all SMCs are ablated at or following the 2/3 gastrula stage, further elongation does not occur. However, if a few SMCs are allowed to remain in 2/3-3/4 gastrulae, elongation continues, although more slowly than in controls. The final length of archenterons in embryos ablated at the 1/3-1/2 gastrula stage is virtually identical to the final length of everted archenterons in LiCl-induced exogastrulae; since filopodial traction is not exerted in either case, an alternate, common mechanism of elongation probably operates in both cases. These results suggest that archenteron elongation involves two processes: (1) active, filopodia-independent elongation, which depends on active cell rearrangement and (2) filopodia-dependent elongation, which depends on mechanical tension exerted by the filopodia.


1999 ◽  
Vol 147 (6) ◽  
pp. 1261-1274 ◽  
Author(s):  
Shuo Ma ◽  
Leda Triviños-Lagos ◽  
Ralph Gräf ◽  
Rex L. Chisholm

Cytoplasmic dynein intermediate chain (IC) mediates dynein–dynactin interaction in vitro (Karki, S., and E.L. Holzbaur. 1995. J. Biol. Chem. 270:28806–28811; Vaughan, K.T., and R.B. Vallee. 1995. J. Cell Biol. 131:1507–1516). To investigate the physiological role of IC and dynein–dynactin interaction, we expressed IC truncations in wild-type Dictyostelium cells. ICΔC associated with dynactin but not with dynein heavy chain, whereas ICΔN truncations bound to dynein but bound dynactin poorly. Both mutations resulted in abnormal localization to the Golgi complex, confirming dynein function was disrupted. Striking disorganization of interphase microtubule (MT) networks was observed when mutant expression was induced. In a majority of cells, the MT networks collapsed into large bundles. We also observed cells with multiple cytoplasmic asters and MTs lacking an organizing center. These cells accumulated abnormal DNA content, suggesting a defect in mitosis. Striking defects in centrosome morphology were also observed in IC mutants, mostly larger than normal centrosomes. Ultrastructural analysis of centrosomes in IC mutants showed interphase accumulation of large centrosomes typical of prophase as well as unusually paired centrosomes, suggesting defects in centrosome replication and separation. These results suggest that dynactin-mediated cytoplasmic dynein function is required for the proper organization of interphase MT network as well as centrosome replication and separation in Dictyostelium.


1982 ◽  
Vol 92 (3) ◽  
pp. 733-741 ◽  
Author(s):  
S M Penningroth ◽  
A Cheung ◽  
K Olehnik ◽  
R Koslosky

The relaxation (straightening) of flagellar rigor waves, which is known to be induced by micromolar ATP concentrations was investigated with respect to its dependence on the binding and hydrolysis of ATP. Flagellar rigor waves were formed by the dilution of demembranated, reactivated sea urchin (Lytechinus pictus) spermatozoa into ATP-free buffer. Relaxation in response to nucleotide was quantitated by measuring theta, the mean flagellar bend angle per sperm; this novel assay permitted determination of the rate of relaxation. It was found that (a) the rate of flagellar relaxation induced by 4 X 10(-6) M ATP was inhibited 80% by vanadate concentrations of 3 X 10(-6) M and above; (b) of 16 hydrolyzable and nonhydrolyzable nucleotide di-, tri-, and tetraphosphates tested, only three, each of which was hydrolyzed by the flagellar axonemal ATPase activity (ATP, dATP, and epsilon-ATP) were also capable of effecting relaxation; (c) several hundred ATP molecules were estimated to be hydrolyzed by each dynein of ATP hydrolysis, which defines the efficiency of ATP utilization, increased 30-fold as the ATP relaxation depends on ATP hydrolysis; (b) because it depends on ATP hydrolysis, flagellar relaxation is an inappropriate model system for investigating the role of ATP binding in the mechanochemical cycle of dynein; and (c) the efficiency of mechanochemical coupling in flagellar motility is an ATP-dependent phenomenon. A general model of relaxation is proposed based on active microtubule sliding.


1995 ◽  
Vol 6 (6) ◽  
pp. 685-696 ◽  
Author(s):  
K Ogawa ◽  
R Kamiya ◽  
C G Wilkerson ◽  
G B Witman

Immunological analysis showed that antibodies against the intermediate chains (ICs) IC2 and IC3 of sea urchin outer arm dynein specifically cross-reacted with intermediate chains IC78 and IC69, respectively, of Chlamydomonas outer arm dynein. In contrast, no specific cross-reactivity with any Chlamydomonas outer arm polypeptide was observed using antibody against IC1 of sea urchin outer arm dynein. To learn more about the relationships between the different ICs, overlapping cDNAs encoding all of IC2 and IC3 of sea urchin were isolated and sequenced. Comparison of these sequences with those previously obtained for the Chlamydomonas ICs revealed that, although all four chains are homologous, sea urchin IC2 is much more closely related to Chlamydomonas IC78 (45.8% identity), and sea urchin IC3 is much more closely related to Chlamydomonas IC69 (48.5% identity), than either sea urchin chain is related to the other (23.5% identity). For homologous pairs, the similarities extend throughout the full lengths of the chains. Regions of similarity between all four ICs and the IC (IC74) of cytoplasmic dynein, located in the C-terminal halves of the chains, are due primarily to conservation of the WD repeats present in all of these ICs. This is the first demonstration that structural differences between individual ICs within an outer arm dynein have been highly conserved in the dyneins of distantly related species. The results provide a basis for the subclassification of these chains.


1978 ◽  
Vol 79 (3) ◽  
pp. 827-832 ◽  
Author(s):  
S M Penningroth ◽  
G B Witman

A nonhydrolyzable ATP analog, adenylyl imidodiphosphate (AMP-PNP), has been used to study the role of ATP binding in flagellar motility. Sea urchin sperm of Lytechinus pictus were demembranated, reactivated, and locked in "rigor waves" by a modification of the method of Gibbons and Gibbons (11). Rigor wave sperm relaxed within 2 min after addition of 4 micrometer ATP, and reactivated upon addition of 10-12 micrometer ATP. The beat frequency of the reactivated sperm varied with ATP concentration according to Michaelis-Menten kinetics ("Km" = 0.24 mM; "Vmax" = 44 Hz) and was competitively inhibited by AMP-PNP (Ki" approximately to 8.1 mM). Rigor wave sperm were completely relaxed (straightened) within 2 min by AMP-PNP at concentrations of 2-4 mM. The possibilities that relaxation in AMP-PNP was a result of ATP contamination, AMP-PNP hydrolysis, or lowering of the free Mg++ concentration were conclusively ruled out. The results suggest that dynein cross-bridge release is dependent upon ATP binding but not hydrolysis.


1996 ◽  
Vol 7 (12) ◽  
pp. 1895-1907 ◽  
Author(s):  
K Ogawa ◽  
H Takai ◽  
A Ogiwara ◽  
E Yokota ◽  
T Shimizu ◽  
...  

The outer arm dynein of sea urchin sperm axoneme contains three intermediate chains (IC1, IC2, and IC3; M(r) 128,000, 98,000, and 74,000, respectively). IC2 and IC3 are members of the WD family; the WD motif is responsible for a protein-protein interaction. We describe here the molecular cloning of IC1. IC1 has a unique primary structure, the N-terminal part is homologous to the sequence of thioredoxin, the middle part consists of three repetitive sequences homologous to the sequence of nucleoside diphosphate kinase, and the C-terminal part contains a high proportion of negatively charged glutamic acid residues. Thus, IC1 is a novel dynein intermediate chain distinct from IC2 and IC3 and may be a multifunctional protein. The thioredoxin-related part of IC1 is more closely related to those of two redox-active Chlamydomonas light chains than thioredoxin. Antibodies were prepared against the N-terminal and middle domains of IC1 expressed as His-tagged proteins in bacteria. These antibodies cross-reacted with some dynein polypeptides (potential homologues of IC1) from distantly related species. We propose here that the three intermediate chains are the basic core units of sperm outer arm dynein because of their ubiquitous existence. The recombinant thioredoxin-related part of IC1 and outer arm dyneins from sea urchin and distantly related species were specifically bound to and eluted from a phenylarsine oxide affinity column with 2-mercaptoethanol, indicating that they contain vicinal dithiols competent to undergo reversible oxidation/reduction.


Development ◽  
1997 ◽  
Vol 124 (1) ◽  
pp. 13-20 ◽  
Author(s):  
A.H. Wikramanayake ◽  
W.H. Klein

In the sea urchin embryo, the animal-vegetal axis is established during oogenesis and the oral-aboral axis is specified sometime after fertilization. The mechanisms by which either of these axes are specified and patterned during embryogenesis are poorly understood. Here, we investigated the role of cellular interactions in the specification of the ectoderm territories and polarization of the ectoderm along the oral-aboral axis. Isolated animal halves (mesomeres), which are fated to give rise to oral and aboral ectoderm, developed into polarized embryoids that expressed an oral ectoderm-specific marker uniformly. These embryoids also produced neuron-like cells and serotonergic neurons, suggesting that mesomeres are autonomously specified as oral ectoderm. Mesomere-derived embryoids did not express any aboral ectoderm-specific markers, although we previously showed that aboral ectoderm-specific genes can be induced by 25 mM lithium chloride, which also induced endoderm formation (Wikramanayake, A. H., Brandhorst, B. P. and Klein, W. H.(1995). Development 121, 1497–1505). To ascertain if endoderm formation is a prerequisite for induction of aboral ectoderm by lithium and for normal ectoderm patterning in animal halves, we modulated the lithium treatment to ensure that no endoderm formed. Remarkably, treating animal halves with 10 mM LiCl at approximately 7 hours postfertilization resulted in embryoids that displayed oral-aboral axis patterning in the absence of endoderm. Application of 25 mM LiCl to animal halves at approximately 16 hours postfertilization, which also did not induce endoderm, resulted in polarized expression of the aboral ectoderm-specific LpS1 protein, but global expression of the Ecto V antigen and no induction of the stomodeum or ciliary band. These results suggest that at least two signals, a positive inductive signal to specify the aboral ectoderm and a negative suppressive signal to inactivate oral ectoderm-specific genes in the prospective aboral ectoderm territory, are needed for correct spatial expression of oral and aboral ectoderm-specific genes. Transmission of both these signals may be prerequisite for induction of secondary ectodermal structures such as the ciliary band and stomodeum. Thus, differentiation of ectoderm and polarization of the oral-aboral axis in Lytechinus pictus depends on cellular interactions with vegetal blastomeres as well as interactions along the oral-aboral axis.


2013 ◽  
Vol 24 (17) ◽  
pp. 2668-2677 ◽  
Author(s):  
Ramila S. Patel-King ◽  
Renée M. Gilberti ◽  
Erik F. Y. Hom ◽  
Stephen M. King

Retrograde intraflagellar transport (IFT) is required for assembly of cilia. We identify a Chlamydomonas flagellar protein (flagellar-associated protein 163 [FAP163]) as being closely related to the D1bIC(FAP133) intermediate chain (IC) of the dynein that powers this movement. Biochemical analysis revealed that FAP163 is present in the flagellar matrix and is actively trafficked by IFT. Furthermore, FAP163 copurified with D1bIC(FAP133) and the LC8 dynein light chain, indicating that it is an integral component of the retrograde IFT dynein. To assess the functional role of FAP163, we generated an RNA interference knockdown of the orthologous protein (WD60) in planaria. The Smed-wd60(RNAi) animals had a severe ciliary assembly defect that dramatically compromised whole-organism motility. Most cilia were present as short stubs that had accumulated large quantities of IFT particle–like material between the doublet microtubules and the membrane. The few remaining approximately full-length cilia had a chaotic beat with a frequency reduced from 24 to ∼10 Hz. Thus WD60/FAP163 is a dynein IC that is absolutely required for retrograde IFT and ciliary assembly.


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