A5084381004- Microtubule and mitosis dynamics
- Genetic and Kidney Cyst Diseases
- Protist diversity and phylogeny
- Photosynthetic Processes and Mechanisms
- Micro and Nano Robotics
- Quantum chaos and dynamical systems
- Cellular transport and secretion
- Quantum Computing Algorithms and Architecture
- Antibiotic Resistance in Bacteria
- Hemoglobin structure and function
- Quantum Mechanics and Applications
- Cystic Fibrosis Research Advances
- Cold Atom Physics and Bose-Einstein Condensates
- Molecular spectroscopy and chirality
- Advanced Chemical Physics Studies
- Legume Nitrogen Fixing Symbiosis
- Metalloenzymes and iron-sulfur proteins
- Nonlinear Dynamics and Pattern Formation
- Characterization and Applications of Magnetic Nanoparticles
- Seismic Imaging and Inversion Techniques
- Spectroscopy and Quantum Chemical Studies
- Renal and related cancers
- Neurological disorders and treatments
- Electrohydrodynamics and Fluid Dynamics
- Diet and metabolism studies
SUNY Upstate Medical University
2011-2023
College of Saint Benedict and Saint John's University
2005-2017
University of Virginia
2013
Talisman Energy
2008
St. John's University
2005
Northwestern State University
2004-2005
Jet Propulsion Laboratory
2005
Saint Joseph Seminary College
2005
University of Colorado Boulder
2004
Emory University
1999
A new Chlamydomonas flagellar mutant, pf-28, which swims more slowly than wild-type cells, was selected. Thin-section electron microscopy revealed the complete absence of outer-row dynein arms in this whereas inner-row and other axonemal structures appeared normal. SDS PAGE analysis also indicated that polypeptides previously identified as outer-arm components are completely absent pf-28. The two ATPases retained by mutant sediment at 17.7S 12.7S on sucrose gradients contain 0.6 M KCl....
Previous work has revealed a cytoplasmic pool of flagellar precursor proteins capable contributing to the assembly new flagella, but how and where these components assemble is unknown. We tested Chlamydomonas outer-dynein arm subunit stability in cytoplasm wild-type cells 11 outer dynein mutant strains (oda1-oda11) by Western blotting extracts, or immunoprecipitates from with five outer-row subunit-specific antibodies. blots reveal that at least three oda mutants (oda6, oda7, oda9) alter...
Formation of flagellar outer dynein arms in Chlamydomonas reinhardtii requires the ODA16 protein at a previously uncharacterized assembly step. Here, we show that extracted from wild-type axonemes can rebind to oda16 vitro, and cytoplasmic extracts bind docking sites on pf28 (oda) axonemes, which is consistent with role for transport, rather than subunit preassembly or binding site formation. localization resembles seen intraflagellar transport (IFT) proteins, abundance depends IFT. Yeast...
We find that two Chlamydomonas outer arm dynein assembly loci, oda6 and oda9, are located on the left of linkage group XII, in vicinity previously mapped locus for a 70,000 Mr intermediate chain protein. Restriction fragment length polymorphism mapping indicates this gene is very closely linked to locus. A cDNA clone encoding protein was isolated, sequenced, used select genomic clones spanning corresponding from both wild-type libraries. When were introduced into cells containing an allele,...
A novel Chlamydomonas flagellar mutant (oda-11) missing the alpha heavy chain of outer arm dynein but retaining beta and gamma chains was isolated. Restriction fragment length polymorphism analysis with an locus genomic probe indicated that oda-11 mutation genetically linked structural gene chain. In cross-section electron micrographs, axoneme lacked outermost appendage arm, indicating should be located in this region wild-type arm. This swam at 119 microns/s 25 degrees C, i.e., intermediate...
Abstract Cilia and flagella are conserved hair‐like appendages of eukaryotic cells that function as sensing motility generating organelles. Motility is driven by thousands axonemal dyneins require precise regulation. One essential regulator the central pair complex (CPC) many CPC defects cause paralysis cilia/flagella. Several human diseases, such immotile cilia syndrome, show abnormalities, but little known about detailed three‐dimensional (3D) structure CPC. The located in center typical...
Two alleles at a new locus, central pair–associated complex 1 (CPC1), were selected in screen for Chlamydomonas flagellar motility mutations. These mutations disrupt structures associated with pair microtubules and reduce beat frequency, but do not prevent changes activity either photophobic responses or phototactic accumulation of live cells. Comparison cpc1 pf6 axonemes shows that affects row projections along C1 distinct from those missing pf6, thin fibers form an arc between the two...
We have characterized a group of regulatory mutations that alter the activity outer dynein arms. Three were obtained as suppressors paralyzed central pair mutant pf6 (Luck, D.J.L., and G. Piperno. 1989. Cell Movement. pp. 49-60), whereas two others pfl6. Recombination analysis complementation tests indicate all five are alleles at SUP-PF-1/ODA4 locus each allele can restore motility to radial spoke defective strains. Restriction fragment length polymorphism with genomic probe for beta-dynein...
Eukaryotic cilia and flagella are long, thin organelles, diffusion from the cytoplasm may not be able to support high ATP concentrations needed for dynein motor activity. We discovered enzyme activities in Chlamydomonas reinhardtii flagellum that catalyze three steps of lower half glycolysis (phosphoglycerate mutase, enolase, pyruvate kinase). These enzymes can generate one molecule every substrate consumed. Flagellar fractionation shows enolase is at least partially associated with axoneme,...
Regulation of motile 9+2 cilia and flagella depends on interactions between radial spokes a central pair apparatus. Although the rotates during bend propagation in many organisms rotation correlates with twisted structure, propulsive forces for twist are unknown. Here we compared conformation straight, quiescent to that actively beating using wild-type Chlamydomonas reinhardtii mutants lack spoke heads. Twists occur both presence absence heads, indicating spoke–central not needed generate...
Several flagellar dynein ATPase and radial spokehead genes have been isolated from a Chlamydomonas genomic expression library in lambda gt11. The was probed with polyclonal monoclonal antibodies raised against purified polypeptides, recombinant phage giving positive signals were cloned. In vitro translation of mRNAs hybrid-selected by the cloned sequences whole cell RNA provided confirmation identity for three four clones. Evidence supporting identification fourth, which encodes heavy chain,...
Abstract The formation and function of eukaryotic cilia/flagella require the action a large array dynein microtubule motor complexes. Due to genetic, biochemical, microscopic tractability, Chlamydomonas reinhardtii has become premier model system in which dissect role dyneins flagellar assembly, motility, signaling. Currently, 54 proteins have been described as components various or factors required for their assembly cytoplasm and/or transport into flagellum; orthologs nearly all these are...
Outer dynein arms (ODAs) are multiprotein complexes that drive flagellar beating. Based on genetic and biochemical analyses, ODAs preassemble in the cell body then move into flagellum by intraflagellar transport (IFT). To study ODA vivo, we expressed essential intermediate chain 2 tagged with mNeonGreen (IC2-NG) to rescue corresponding Chlamydomonas reinhardtii mutant oda6. IC2-NG moved IFT; was of low processivity increased frequency during growth. As expected, IFT diminished oda16, lacking...
ABSTRACT We have sequenced genomic clones spanning the complete coding region of one heavy chain (beta) and catalytic domain a second (alpha) Chlamydomonas reinhardtii flagellar outer arm dynein ATPase. The beta gene (ODA-4 locus) spans 20 kb, is divided into at least 30 exons, encodes predicted 520 kDa protein. Comparison with sea urchin sequences reveals homology that extends throughout both proteins. Over most conserved central region, alpha chains are equally divergent from (64% 65%...