A mutant of Chlamydomonas reinhardtii that lacks the flagellar outer dynein arm but can swim

1985 ◽  
Vol 74 (1) ◽  
pp. 181-191
Author(s):  
R. Kamiya ◽  
M. Okamoto
Keyword(s):  
Beat Frequency ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Wild Type ◽  
Virtual Absence ◽  
Flagellar Beat ◽  
Type Pattern ◽  
In The Wild ◽  
Swimming Mode ◽  
New Type

A new type of Chlamydomonas mutant, which lacks the outer dynein arm but can swim, was isolated. Sodium dodecyl sulphate/polyacrylamide gel electrophoresis showed that four of the ten high-molecular-weight bands of dynein present in the wild-type axoneme are missing or diminished in the mutant axoneme. The mutant has a swimming rate of about 35 micrometers/s and a flagellar beat frequency of about 25 Hz, both of which are about 1/2.5 to 1/3 of those of the wild type. The mutant flagella beat with an asymmetric, cilia-type pattern, similar to the forward-swimming mode of the flagellar beating pattern of the wild type. However, unlike wild-type flagella, the mutant flagella never beat with a symmetrical waveform: when the cells were stimulated by intense light, the mutant transiently stopped beating its flagella, whereas the wild-type cell transiently swam backwards with the two flagella beating with a symmetrical waveform. Both wild-type and mutant cells could be demembranated by Nonidet P40 and their swimming reactivated by addition of Mg-ATP in the virtual absence of Ca2+. Double reciprocal plots of the beat frequency against ATP concentrations showed a linear relationship for both strains, yielding maximal frequencies of 44 Hz (wild-type) and 23 Hz (mutant). The mutant axonemes can be reactivated only when the Ca2+ concentration is lower than 10(−6) M: at pCa4, the wild-type axonemes beat with a symmetrical waveform, but the mutant axonemes showed no movement. These findings indicate that the outer dynein arm is dispensable for flagellar beating of the asymmetric waveform (forward-swimming mode), but not for beating of the symmetrical waveform (backward-swimming mode), and thus suggest the importance of the outer dynein arm in the switching of flagellar waveforms.

scholarly journals A Chlamydomonas outer arm dynein mutant missing the alpha heavy chain.

1991 ◽  
Vol 113 (3) ◽  
pp. 615-622 ◽  
Author(s):  
H Sakakibara ◽  
D R Mitchell ◽  
R Kamiya
Keyword(s):  
Cross Section ◽  
Heavy Chain ◽  
Fragment Length Polymorphism ◽  
Beat Frequency ◽  
Polymorphism Analysis ◽  
Wild Type ◽  
Heavy Chains ◽  
Flagellar Beat ◽  
Section Electron ◽  
In The Wild

A novel Chlamydomonas flagellar mutant (oda-11) missing the alpha heavy chain of outer arm dynein but retaining the beta and gamma heavy chains was isolated. Restriction fragment length polymorphism analysis with an alpha heavy chain locus genomic probe indicated that the oda-11 mutation was genetically linked with the structural gene of the alpha heavy chain. In cross-section electron micrographs, the oda-11 axoneme lacked the outermost appendage of the outer arm, indicating that the alpha heavy chain should be located in this region in the wild-type outer arm. This mutant swam at 119 microns/s at 25 degrees C, i.e., at an intermediate speed between those of wild type (194 microns/s) and of oda-1 (62 microns/s), a mutant missing the entire outer dynein arm. The flagellar beat frequency (approximately 50 Hz) was also between those of wild type (approximately 60 Hz) and oda-1 (approximately 26 Hz). These results indicate that the outer dynein arm of Chlamydomonas can be assembled without the alpha heavy chain, and that the outer arm missing the alpha heavy chain retains partial function.

Identification of pilin pools in the membranes of Pseudomonas aeruginosa

1982 ◽  
Vol 152 (2) ◽  
pp. 687-691
Author(s):  
T H Watts ◽  
E A Worobec ◽  
W Paranchych
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Gel Electrophoresis ◽  
Type Strain ◽  
Wild Type Strain ◽  
Polyacrylamide Gel Electrophoresis ◽  
Protein A ◽  
Sodium Dodecyl ◽  
Wild Type ◽  
Outer Membranes

The proteins of purified inner and outer membranes obtained from Pseudomonas aeruginosa strains PAK and PAK/2Pfs were subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis, transferred to nitrocellulose, and treated with antiserum raised against pure pili. Bound antipilus antibodies were visualized by reaction with 125I-labeled protein A from Staphylococcus aureus. The results showed that there are pools of pilin in both the inner and outer membranes of P. aeruginosa and that the pool size in the multipiliated strain is comparable with that of the wild-type strain.

Novel Catalatic Proteins of Bakers' Yeast. I. An Atypical Catalase

1973 ◽  
Vol 51 (11) ◽  
pp. 1551-1555 ◽  
Author(s):  
Tony C. M. Seah ◽  
A. R. Bhatti ◽  
J. G. Kaplan
Keyword(s):  
Molecular Weight ◽  
Gel Electrophoresis ◽  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Native Protein ◽  
Wild Type ◽  
Major Band ◽  
Subunit Molecular Weight ◽  
Purification And Properties

At any stage of growth of a wild-type bakers' yeast, some 20% of the catalatic activity of crude extracts is not precipitable by means of antibody prepared against the typical catalase (catalase T), whose purification and properties have been previously described. Some of this catalatic activity is due to the presence of an atypical catalase (catalase A), a heme protein, with a molecular weight estimated as 170 000 – 190 000, considerably lower than that of the usual catalases (225 000 – 250 000). Preparations of catalase A were found to be homogeneous in the analytical ultracentrifuge and in polyacrylamide gel electrophoresis. Its subunit molecular weight, determined from its iron content, was 46 500, virtually the same as that of the major band obtained in gel electrophoresis in the presence of sodium dodecyl sulfate, suggesting that the native protein is tetrameric. Its specific activity is in the range of those reported for other typical catalases.

A Dictyostelium mutant with severe defects in alpha-actinin: its characterization using cDNA probes and monoclonal antibodies

1988 ◽  
Vol 90 (1) ◽  
pp. 59-71
Author(s):  
M. Schleicher ◽  
A. Noegel ◽  
T. Schwarz ◽  
E. Wallraff ◽  
M. Brink ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Polypeptide Chain ◽  
Mutant Cell ◽  
Polyacrylamide Gel Electrophoresis ◽  
Cell Extract ◽  
Binding Activity ◽  
Partial Purification ◽  
Wild Type ◽  
Coding Region ◽  
In The Wild

Cells of a Dictyostelium discoideum mutant deficient in binding a monoclonal antibody to alpha-actinin have previously been shown to grow and develop similarly to the wild type and to exert unimpaired chemotaxis as well as patching and capping of membrane proteins. Here we show that the normal 3.0 kb message for alpha-actinin is replaced in the mutant by two RNA species of approximately 3.1 and 2.8 kb. The 3.1 kb RNA was recognized by DNA fragments from all parts of the coding region, while the 2.8 kb RNA hybridized to all but a 3′-terminal fragment. Proteins synthesized in the mutant were analysed using four monoclonal antibodies that in the wild type specifically recognize the 95 × 10(3) Mr polypeptide of alpha-actinin. Cleavage mapping indicated that the binding sites of these antibodies are distributed over a region comprising more than half of the alpha-actinin polypeptide chain. In the mutant, three of the antibodies faintly labelled two polypeptides of 95 × 10(3) Mr and 88 × 10(3) Mr; the fourth antibody, which binds closest to one end of the polypeptide chain, faintly labelled the 95 × 10(3) Mr polypeptide only. The 88 × 10(3) Mr polypeptide most probably lacks the C-terminal portion of alpha-actinin. The binding of an antibody that recognized both polypeptides was quantified by a radio-immuno competition assay using wild-type alpha-actinin as a reference. In a mutant cell extract containing total soluble proteins the antibody binding activity was decreased to 1.1% when compared with wild-type extract. After their partial purification and SDS-polyacrylamide gel electrophoresis the mutant 95 × 10(3) Mr and 88 × 10(3) Mr polypeptides were barely detectable as Coomassie Blue-stained bands, indicating that in the mutant not only certain epitopes of alpha-actinin were altered but the entire molecule is almost completely lacking. When the fitness of mutant cells relative to wild type was determined during growth in nutrient medium, a slight disadvantage for the mutant was indicated, by finding selection coefficients between 0.03 and 0.05.

Regulation of alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (AldDH) in Aspergillus nidulans

1983 ◽  
Vol 217 (1208) ◽  
pp. 243-264 ◽  
Keyword(s):  
Alcohol Dehydrogenase ◽  
Aspergillus Nidulans ◽  
Structural Gene ◽  
Aldehyde Dehydrogenase ◽  
Gel Electrophoresis ◽  
Regulatory Gene ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Wild Type ◽  
Cell Extracts

There is a single major alcohol dehydrogenase (ADH) and a single major aldehyde dehydrogenase (AldDH) in Aspergillus nidulans . Both ADH and AldDH are induced by ethanol and by acetaldehyde and both are subject to carbon catabolite repression. ADH and AldDH are necessary for the utilization of ethanol and of threonine, indicating that both compounds are utilized via acetaldehyde. ADH and AldDH each give a single major activity band on gel electrophoresis. Sodium dodecyl sulphate polyacrylamide gel electrophoresis of cell extracts shows at least two similar ADH polypeptides of approximate relative molecular mass (r. m. m.) 41000 and two similar AldDH polypeptides of approximate r. m. m. 57000. The in vitro translation of mRNA from induced, carbon derepressed wild-type cells gives up to three ADH polypeptides in the r. m. m. range 39000-43000 and an AldDH polypeptide of approximate r. m. m. 57000. The mRNA from uninduced, carbon repressed wild-type cells does not direct the synthesis of the ADH and AldDH polypeptides. This indicates that the regulation of ADH and AldDH is at the level of transcription and/or post-transcriptional modification. The probable explanation of the multiple ADH polypeptides is post-transcriptional modification of the mRNA. Allyl alcohol mutants were made by using diepoxyoctane and γ-rays as mutagens. There are two classes, alcA and alcR . Neither class can utilize ethanol or threonine as a carbon source. The alcA mutants lack normal ADH and are recessive. Of the 47 alcA mutants examined 39 do not make the ADH polypeptides while eight do so. Therefore alcA is the structural gene for ADH. The two alcA mutants tested do not make functional mRNA for ADH. The alcR mutants lack both ADH and AldDH and are recessive. No alcR mutants make the ADH or the AldDH polypeptides. The three alcR mutants tested do not make functional ADH or AldDH mRNA. The mutant alcR 125 is a nonsense mutant, which establishes that alcR codes for a protein. The alcA and alcR genes are adjacent on chromosome VII and a preliminary fine-structure map of the alcA gene has been made. Three mutants that cannot utilize ethanol or threonine and have ADH, but lack AldDH, define a gene AldA on chromosome VIII. The aldA 23 mutant makes the AldDH polypeptides, the other two aldA mutants do not. Therefore aldA is probably the structural gene for AldDH. Our current hypothesis is that alcA and aldA are the structural genes for ADH and AldDH respectively and alcR is a transacting regulatory gene coding for a protein whose function is necessary for the expression of the alcA and aldA genes.

scholarly journals Influence of Processing Conditions on the Physicochemical Properties of a New-Type of Nutritional Drink—Millet Skim Milk Beverage

Molecules ◽  
2019 ◽  
Vol 24 (7) ◽  
pp. 1338
Author(s):  
Minghui Pan ◽  
Yungang Cao ◽  
Xuelu Chi ◽  
Zheng Song ◽  
Nasi Ai ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Skim Milk ◽  
B Value ◽  
Optimum Process ◽  
Process Conditions ◽  
Color Analysis ◽  
Sds Page ◽  
New Type

In this experiment, a new type of nutritional drink—millet skim milk beverage—was developed based on combining skim milk with millet and nutritional resource utilization. The effects of NaHCO3 concentrations in soaking water (0, 0.5 g/100 mL, and 1.0 g/100 mL) and blanching time (0, 15, and 30 min) on the physicochemical properties of millet skim milk were studied. The parameter changes caused by the above treatment were evaluated via color analysis, physicochemical analysis and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Soaking in water containing NaHCO3 had a significant (p < 0.05) effect on pH, specific gravity, viscosity, and stability. The blanching treatment had a significant (p < 0.05) influence on the total solids of the samples. However, blanching only slightly affected the physical properties of the samples. In addition, soaking and blanching treatments had significant (p < 0.05) effects on the b* value of millet skim milk beverage, whereas there was no significant (p > 0.05) change in L* and a*. SDS-PAGE analysis indicated that the blanching treatment had a significant (p < 0.05) effect on band 5 and band 6 and that the soaking treatment also had a significant effect on the bands of 6 and 7 (p < 0.05). By analyzing the substantial effects, we concluded that the optimum process conditions were soaking with 0.5 g/100 mL NaHCO3 solution and blanching for 15 min.

scholarly journals The Spirochete FlaA Periplasmic Flagellar Sheath Protein Impacts Flagellar Helicity

2000 ◽  
Vol 182 (23) ◽  
pp. 6698-6706 ◽  
Author(s):  
Chunhao Li ◽  
Linda Corum ◽  
David Morgan ◽  
Everett L. Rosey ◽  
Thaddeus B. Stanton ◽  
...  
Keyword(s):  
Blot Analysis ◽  
Type Strain ◽  
Wild Type Strain ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Dark Field ◽  
Wild Type ◽  
Brachyspira Hyodysenteriae ◽  
Flagellar Filament ◽  
Cognate Gene

ABSTRACT Spirochete periplasmic flagella (PFs), including those fromBrachyspira (Serpulina),Spirochaeta, Treponema, andLeptospira spp., have a unique structure. In most spirochete species, the periplasmic flagellar filaments consist of a core of at least three proteins (FlaB1, FlaB2, and FlaB3) and a sheath protein (FlaA). Each of these proteins is encoded by a separate gene. Using Brachyspira hyodysenteriae as a model system for analyzing PF function by allelic exchange mutagenesis, we analyzed purified PFs from previously constructedflaA::cat,flaA::kan, andflaB1::kan mutants and newly constructed flaB2::cat andflaB3::cat mutants. We investigated whether any of these mutants had a loss of motility and altered PF structure. As formerly found withflaA::cat,flaA::kan, andflaB1::kan mutants,flaB2::cat andflaB3::cat mutants were still motile, but all were less motile than the wild-type strain, using a swarm-plate assay. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot analysis indicated that each mutation resulted in the specific loss of the cognate gene product in the assembled purified PFs. Consistent with these results, Northern blot analysis indicated that each flagellar filament gene was monocistronic. In contrast to previous results that analyzed PFs attached to disrupted cells, purified PFs from a flaA::cat mutant were significantly thinner (19.6 nm) than those of the wild-type strain and flaB1::kan,flaB2::cat, andflaB3::cat mutants (24 to 25 nm). These results provide supportive genetic evidence that FlaA forms a sheath around the FlaB core. Using high-magnification dark-field microscopy, we also found thatflaA::cat andflaA::kan mutants produced PFs with a smaller helix pitch and helix diameter compared to the wild-type strain and flaB mutants. These results indicate that the interaction of FlaA with the FlaB core impacts periplasmic flagellar helical morphology.

scholarly journals IC138 Is a WD-Repeat Dynein Intermediate Chain Required for Light Chain Assembly and Regulation of Flagellar Bending

2004 ◽  
Vol 15 (12) ◽  
pp. 5431-5442 ◽  
Author(s):  
Triscia W. Hendrickson ◽  
Catherine A. Perrone ◽  
Paul Griffin ◽  
Kristin Wuichet ◽  
Joshua Mueller ◽  
...  
Keyword(s):  
Light Chain ◽  
Beat Frequency ◽  
Wild Type ◽  
Central Pair ◽  
Flagellar Beat ◽  
C Terminus ◽  
Dynein Intermediate Chain ◽  
Radial Spokes ◽  
Calculated Mass ◽  
Wd Repeat

Increased phosphorylation of dynein IC IC138 correlates with decreases in flagellar microtubule sliding and phototaxis defects. To test the hypothesis that regulation of IC138 phosphorylation controls flagellar bending, we cloned the IC138 gene. IC138 encodes a novel protein with a calculated mass of 111 kDa and is predicted to form seven WD-repeats at the C terminus. IC138 maps near the BOP5 locus, and bop5-1 contains a point mutation resulting in a truncated IC138 lacking the C terminus, including the seventh WD-repeat. bop5-1 cells display wild-type flagellar beat frequency but swim slower than wild-type cells, suggesting that bop5-1 is altered in its ability to control flagellar waveform. Swimming speed is rescued in bop5-1 transformants containing the wild-type IC138, confirming that BOP5 encodes IC138. With the exception of the roadblock-related light chain, LC7b, all the other known components of the I1 complex, including the truncated IC138, are assembled in bop5-1 axonemes. Thus, the bop5-1 motility phenotype reveals a role for IC138 and LC7b in the control of flagellar bending. IC138 is hyperphosphorylated in paralyzed flagellar mutants lacking radial spoke and central pair components, further indicating a role for the radial spokes and central pair apparatus in control of IC138 phosphorylation and regulation of flagellar waveform.

scholarly journals An analysis of discoidin I binding sites in Dictyostelium discoideum (NC4)

1981 ◽  
Vol 200 (1) ◽  
pp. 83-91 ◽  
Author(s):  
I C Madley ◽  
B D Hames
Keyword(s):  
Binding Sites ◽  
Bacterial Contamination ◽  
Wild Type Strain ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Specific Radioactivity ◽  
Wild Type ◽  
Stage Of Development ◽  
Affinity Constants ◽  
Radioactivity Measurements

Vegetative wild-type (strain NC4) D. discoideum cells and cells at the 10h stage of development (aggregation) were harvested in the presence of 0.5 M-galactose to remove any endogenous discoidin I already bound to the cell surface, and fixed with glutaraldehyde. Affinity-purified 125I-labelled discoidin I bound to these fixed cells in a specific manner, greater than or equal to 95% of binding being inhibited by 0.5 M-galactose. Binding of 125I-labelled discoidin I was essentially complete in 90 min at 22 degrees C. Based on specific radioactivity measurements, vegetative (0h) D. discoideum (NC4) cells bind approx. 8.4 x 10(5) discoidin I tetramers/cell and aggregated (10h) cells bind 5.1 x 10(5) discoidin I tetramers/cell, each exhibiting apparent positive co-operativity of binding with highest limiting affinity constants (Ka) of approx. 1 x 10(7) and 2 x 10(7) M-1, respectively. Klebsiella aerogenes, the food source used for growth of D. discoideum NC4 amoebae, also binds 125I-labelled discoidin I and this is greater than 99% inhibited by 0.5 M-galactose. However, at the levels of bacterial contamination present, greater than 97% of 125I-labelled discoidin I binding to D. discoideum cell preparations was to the cells themselves. Confirmation of the number of discoidin I tetramers bound per D. discoideum cell was obtained by elution of bound 125I-labelled discoidin I followed by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and then quantification by scanning of stained discoidin I bands.

scholarly journals Proteins Associated with the Myxococcus xanthus Extracellular Matrix

2007 ◽  
Vol 189 (21) ◽  
pp. 7634-7642 ◽  
Author(s):  
Patrick D. Curtis ◽  
James Atwood ◽  
Ron Orlando ◽  
Lawrence J. Shimkets
Keyword(s):  
Extracellular Matrix ◽  
Biofilm Formation ◽  
Myxococcus Xanthus ◽  
Sodium Dodecyl ◽  
Wild Type ◽  
Fruiting Body Formation ◽  
Ecm Proteins ◽  
Chromatography Tandem Mass Spectrometry ◽  
Liquid Chromatography Tandem Mass ◽  
In The Wild

ABSTRACT Fruiting body formation of Myxococcus xanthus, like biofilm formation of many other organisms, involves the production of an extracellular matrix (ECM). While the polysaccharide component has been studied, the protein component has been largely unexplored. Proteins associated with the ECM were solubilized from purified ECM by boiling with sodium dodecyl sulfate and were identified by liquid chromatography-tandem mass spectrometry of tryptic fragments. The ECM is enriched in proteins of novel function; putative functions were assigned for only 5 of the 21 proteins. Thirteen putative ECM proteins had lipoprotein secretion signals. The genes for many ECM proteins were disrupted in the wild-type (WT), fibA, and pilA backgrounds. Disruption of the MXAN4860 gene had no effect in the WT or fibA background but in the pilA background resulted in a 24-h delay in aggregation and sporulation compared to its parent. The results of this study show that the M. xanthus ECM proteome is diverse and novel.

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