Autophagic elimination of ribosomes during spermiogenesis provides energy for flagellar motility

The hemoflagellateTrypanosoma cruziis the causative agent of American trypanosomiasis. Despite the importance of motility in the parasite life cycle, little is known aboutT. cruzimotility, and there is no quantitative description of its flagellar beating. Using video microscopy and quantitative vectorial analysis of epimastigote trajectories, we find a forward parasite motility defined by tip-to-base symmetrical flagellar beats. This motion is occasionally interrupted by base-to-tip highly asymmetric beats, which represent the ciliary beat of trypanosomatid flagella. The switch between flagellar and ciliary beating facilitates the parasite's reorientation, which produces a large variability of movement and trajectories that results in different distance ranges traveled by the cells. An analysis of the distance, speed, and rotational angle indicates that epimastigote movement is not completely random, and the phenomenon is highly dependent on the parasite behavior and is characterized by directed and tumbling parasite motion as well as their combination, resulting in the alternation of rectilinear and intricate motility paths.

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Biophysics of flagellar motility

Quarterly Reviews of Biophysics ◽

10.1017/s0033583500002742 ◽

1979 ◽

Vol 12 (2) ◽

pp. 103-180 ◽

Cited By ~ 49

Author(s):

Jacob J. Blum ◽

Michael Hines

Keyword(s):

Viscous Medium ◽

Hydrodynamic Interactions ◽

Eukaryotic Cells ◽

Flagellar Motility ◽

Muscle System ◽

Structured Products ◽

Filament System ◽

Complex Organization ◽

Propagating Waves ◽

Sudden Appearance

One feature characterizing the transition from prokaryote to eukaryote is the ‘sudden’ appearance of centrioles and their highly structured products, the typical eukaryotic flagella and cilia. These mechanochemical systems appear as fully developed machines, containing some 200 diffierent proteins (Luck et al. 1978) arranged in a remarkably complex organization which has undergone little modification since the advent of the first eukaryotic cells. It is now well established (see, for example, Satir, 1974) that ciliary and flagellar motility is based on a sliding filament mechanism that superficially resembles the far more extensively studied sliding filament system of striated skeletal muscle.The flagellar system, however, appears to be much more complex than the muscle system, because it does not ‘merely’ shorten and generate force, but develops propagating waves and exerts its effects via hydrodynamic interactions with a viscous medium.

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Specific Control of Pseudomonas aeruginosa Surface-Associated Behaviors by Two c-di-GMP Diguanylate Cyclases

mBio ◽

10.1128/mbio.00183-10 ◽

2010 ◽

Vol 1 (4) ◽

Cited By ~ 106

Author(s):

Judith H. Merritt ◽

Dae-Gon Ha ◽

Kimberly N. Cowles ◽

Wenyun Lu ◽

Diana K. Morales ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Biofilm Formation ◽

Extracellular Polysaccharide ◽

Diguanylate Cyclase ◽

Flagellar Motility ◽

Critical Question ◽

Cyclic Diguanylate ◽

Critical Signal ◽

Content Type ◽

Wide Range

ABSTRACT The signaling nucleotide cyclic diguanylate (c-di-GMP) regulates the transition between motile and sessile growth in a wide range of bacteria. Understanding how microbes control c-di-GMP metabolism to activate specific pathways is complicated by the apparent multifold redundancy of enzymes that synthesize and degrade this dinucleotide, and several models have been proposed to explain how bacteria coordinate the actions of these many enzymes. Here we report the identification of a diguanylate cyclase (DGC), RoeA, of Pseudomonas aeruginosa that promotes the production of extracellular polysaccharide (EPS) and contributes to biofilm formation, that is, the transition from planktonic to surface-dwelling cells. Our studies reveal that RoeA and the previously described DGC SadC make distinct contributions to biofilm formation, controlling polysaccharide production and flagellar motility, respectively. Measurement of total cellular levels of c-di-GMP in ∆roeA and ∆sadC mutants in two different genetic backgrounds revealed no correlation between levels of c-di-GMP and the observed phenotypic output with regard to swarming motility and EPS production. Our data strongly argue against a model wherein changes in total levels of c-di-GMP can account for the specific surface-related phenotypes of P. aeruginosa. IMPORTANCE A critical question in the study of cyclic diguanylate (c-di-GMP) signaling is how the bacterial cell integrates contributions of multiple c-di-GMP-metabolizing enzymes to mediate its cognate functional outputs. One leading model suggests that the effects of c-di-GMP must, in part, be localized subcellularly. The data presented here show that the phenotypes controlled by two different diguanylate cyclase (DGC) enzymes have discrete outputs despite the same total level of c-di-GMP. These data support and extend the model in which localized c-di-GMP signaling likely contributes to coordination of the action of the multiple proteins involved in the synthesis, degradation, and/or binding of this critical signal.

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Multiple protein kinase activities required for activation of sperm flagellar motility

Cell Motility and the Cytoskeleton ◽

10.1002/cm.970320108 ◽

1995 ◽

Vol 32 (1) ◽

pp. 65-79 ◽

Cited By ~ 21

Author(s):

Prem S. Chaudhry ◽

Susan Creagh ◽

Nam Yu ◽

Charles J. Brokaw

Keyword(s):

Protein Kinase ◽

Flagellar Motility ◽

Multiple Protein

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IC138 Defines a Subdomain at the Base of the I1 Dynein That Regulates Microtubule Sliding and Flagellar Motility

Molecular Biology of the Cell ◽

10.1091/mbc.e09-04-0277 ◽

2009 ◽

Vol 20 (13) ◽

pp. 3055-3063 ◽

Cited By ~ 43

Author(s):

Raqual Bower ◽

Kristyn VanderWaal ◽

Eileen O'Toole ◽

Laura Fox ◽

Catherine Perrone ◽

...

Keyword(s):

Double Mutant ◽

Essential Role ◽

Null Allele ◽

Flagellar Motility ◽

Wild Type ◽

Gene Encoding ◽

Radial Spoke ◽

Mutant Strains ◽

Dynein Arms ◽

Image Averaging

To understand the mechanisms that regulate the assembly and activity of flagellar dyneins, we focused on the I1 inner arm dynein (dynein f) and a null allele, bop5-2, defective in the gene encoding the IC138 phosphoprotein subunit. I1 dynein assembles in bop5-2 axonemes but lacks at least four subunits: IC138, IC97, LC7b, and flagellar-associated protein (FAP) 120—defining a new I1 subcomplex. Electron microscopy and image averaging revealed a defect at the base of the I1 dynein, in between radial spoke 1 and the outer dynein arms. Microtubule sliding velocities also are reduced. Transformation with wild-type IC138 restores assembly of the IC138 subcomplex and rescues microtubule sliding. These observations suggest that the IC138 subcomplex is required to coordinate I1 motor activity. To further test this hypothesis, we analyzed microtubule sliding in radial spoke and double mutant strains. The results reveal an essential role for the IC138 subcomplex in the regulation of I1 activity by the radial spoke/phosphorylation pathway.

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