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Articles 1 - 9 of 9
Full-Text Articles in Biology
The Effects Of Tubulin Post-Translational Modifications On The Flagellar Motility Of Trypanosoma Brucei, Katherine Wentworth
The Effects Of Tubulin Post-Translational Modifications On The Flagellar Motility Of Trypanosoma Brucei, Katherine Wentworth
All Theses
Trypanosoma brucei is a parasitic kinetoplastid that causes African trypanosomiasis and is transmitted to a mammalian host by the tsetse fly (Glossina spp.). T. brucei relies on its flagellar motility to carry out its morphological changes from the procyclic form (predominant in the fly vector) to the bloodstream form (infectious form in mammals) and navigate the bloodstream of its host. The driving structure within the flagellum is the axoneme, which is composed of microtubules and dynein motor proteins. The tubulin code hypothesis suggests that cells regulate microtubule motor protein activity through post-translational modifications (PTMs) of alpha and beta …
Probing For Binding Regions Of The Ftsz Protein Surface Through Site-Directed Insertions: Discovery Of Fully Functional Ftsz-Fluorescent Proteins, Desmond A. Moore, Zakiya N. Whatley, Chandra P. Joshi, Masaki Osawa, Harold P. Erickson
Probing For Binding Regions Of The Ftsz Protein Surface Through Site-Directed Insertions: Discovery Of Fully Functional Ftsz-Fluorescent Proteins, Desmond A. Moore, Zakiya N. Whatley, Chandra P. Joshi, Masaki Osawa, Harold P. Erickson
Biology Faculty Publications
FtsZ, a bacterial tubulin homologue, is a cytoskeletal protein that assembles into protofilaments that are one subunit thick. These protofilaments assemble further to form a “Z ring” at the center of prokaryotic cells. The Z ring generates a constriction force on the inner membrane and also serves as a scaffold to recruit cell wall remodeling proteins for complete cell division in vivo. One model of the Z ring proposes that protofilaments associate via lateral bonds to form ribbons; however, lateral bonds are still only hypothetical. To explore potential lateral bonding sites, we probed the surface of Escherichia coli FtsZ …
Analyses Of Chromosome Copy Number And Expression Level Of Four Genes In The Ciliate Chilodonella Uncinata Reveal A Complex Pattern That Suggests Epigenetic Regulation, Laure Bellec, Laura A. Katz
Analyses Of Chromosome Copy Number And Expression Level Of Four Genes In The Ciliate Chilodonella Uncinata Reveal A Complex Pattern That Suggests Epigenetic Regulation, Laure Bellec, Laura A. Katz
Biological Sciences: Faculty Publications
Chilodonella uncinata, like all ciliates, contains two distinct nuclei in every cell: a germline micronucleus and a somatic macronucleus. The macronucleus develops from the zygotic nucleus through a series of chromosomal rearrangements. Macronuclear development in C. uncinata yields a nucleus with highly amplified gene-sized chromosomes. The macronucleus is transcriptionally active during vegetative growth while there is no expression in the micronucleus except during a brief period following conjugation. Gene family evolution in ciliates occurs through complex processes including gene duplication and an alternative processing of scrambled genes. Here we use quantitative PCR to compare relative expression levels of eight genes …
Characterization Of Microtubule Depolymerization By The Hiv Protein Rev, Shimpi Bedi
Characterization Of Microtubule Depolymerization By The Hiv Protein Rev, Shimpi Bedi
Browse all Theses and Dissertations
The HIV-1 Rev protein enables the nucleocytoplasmic export of unspliced or partially spliced mRNAs that is required for the synthesis of structural proteins. By doing so, it regulates the switch to the late phase of the viral replication cycle (Cullen, 1992). This regulatory control over viral replication makes Rev an attractive target for anti-viral intervention. The development of anti-viral remedies is hindered because the three-dimensional structure of Rev has not yet been solved by X-ray crystallography and NMR. Rev, which polymerizes into regular hollow filaments at high concentrations, forms side-to-side and end-to-side interactions making it prone to aggregation and precipitation …
Investigation Of Interactions Between Rev And Microtubules: Purification Of Wild-Type And Mutant Rev Protein And Optimization Of Microtubule Depolymerization Assays, Miller, Kelly Robbins
Investigation Of Interactions Between Rev And Microtubules: Purification Of Wild-Type And Mutant Rev Protein And Optimization Of Microtubule Depolymerization Assays, Miller, Kelly Robbins
Browse all Theses and Dissertations
As a logical pharmaceutical target for antiviral drugs, HIV-1 Rev is a regulatory protein essential for viral infection (Hope, 1999). The development of antiviral drugs that target Rev has been hindered by the lack of high-resolution structural information due to the protein's tendency to aggregate in solution. While searching for solution conditions rendering Rev amenable to crystallographic analyses, Watts et al., (2000) discovered a novel in vitro interaction between Rev and microtubules (MTs) whereby addition of equimolar Rev and tubulin forms bilayered rings called Rev-tubulin toroidal complexes (RTTs). RTTs are similar to those seen when MTs are mixed with certain …
Improved Methods For Preserving Macromolecular Structures And Visualizing Them By Fluorescence And Scanning Electron Microscopy, Paul B. Bell Jr., Barbara Safiejko-Mroczka
Improved Methods For Preserving Macromolecular Structures And Visualizing Them By Fluorescence And Scanning Electron Microscopy, Paul B. Bell Jr., Barbara Safiejko-Mroczka
Scanning Microscopy
To determine the optimal procedures to preserve cytoskeletal and other macromolecular structures for microscopic studies we have evaluated the effects of various methods to extract cultured cells. In this report, we compare results using different fixatives, crosslinking reagents, and permeabilization methods on (1) the labeling of cells for fluorescence microscopy with phalloidin or antibody against tubulin; and (2) the morphological preservation of macromolecular structures for scanning electron microscopy. Maximal labeling of F-actin with phalloidin was obtained by fixing cells in 4% para formaldehyde (PFA) and labeling the unextracted cells with methanolic phalloidin, whereas maximal labeling of tubulin required prefixation with …
The Effects Of Diethyldithiocarbamate (Ddc) On The Astrocytic Cytoskeleton, Mary F. Mcmanus, Louis D. Trombetta
The Effects Of Diethyldithiocarbamate (Ddc) On The Astrocytic Cytoskeleton, Mary F. Mcmanus, Louis D. Trombetta
Scanning Microscopy
The dithiocarbamates are a group of compounds that are used extensively in industry, agriculture and medicine. Exposure to these compounds has caused deleterious effects to both the central and peripheral nervous systems. Cultured rat hippocampal astroglia treated with 35 μg/ml diethyldithiocarbamate (DDC) in media were studied for alterations to the cytoskeleton. Examination by both immunohistochemistry and scanning electron microscopy revealed disruption of the cytoskeletal elements. This occurred in a progressive time-dependent manner. Electrophoretic patterns demonstrated two cytoskeletal protein alterations. The microtubular protein, β-tubulin, appeared to have an altered mobility while the major intermediate filament protein, glial fibrillary acidic protein (GF …
The Cytoskeletal System Of Nucleated Erythrocytes. I. Composition And Function Of Major Elements, William D. Cohen, Diana Bartelt, Richard Jaeger, George M. Langford, Iris Nemhauser
The Cytoskeletal System Of Nucleated Erythrocytes. I. Composition And Function Of Major Elements, William D. Cohen, Diana Bartelt, Richard Jaeger, George M. Langford, Iris Nemhauser
Biology - All Scholarship
We have studied the dogfish erythrocyte cytoskeletal system, which consists of a marginal band of microtubules (MB) and trans-marginal band material (TBM). The TBM appeared in whole mounts as a rough irregular network and in thin sections as a surface-delimiting layer completely enclosing nucleus and MB. In cells incubated at 0 degrees C for 30 min or more, the MB disappeared but the TBM remained. MB reassembly occurred with rewarming, and was inhibited by colchicine. Flattened elliptical erythrocyte morphology was retained even when MBs were absent. Total solubilization of MB and TBM at low pH, or dissolution of whole anucleate …
Arrangement Of Subunits In Microtubules With 14 Profilaments, George M. Langford
Arrangement Of Subunits In Microtubules With 14 Profilaments, George M. Langford
Biology - All Scholarship
The structure of 14-protofilament microtubules reassembled from dogfish shark brain tubulin was analyzed by high resolution electron microscopy and optical diffraction. The simultaneous imaging of the protofilaments from near and far sides of these tubules produces a moiré pattern with a period of approximately 96 nm. Optical diffraction patterns show that the 5-nm spots that arise from the protofilaments for the two sides of the tubule are not coincident but lie off the equator by a distance of 1/192 nm-1. These data provide evidence that in reassembled microtubules containing 14 protofilaments, the protofilaments are tilted 1.5 degrees with respect to …