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Biochemistry, Biophysics, and Structural Biology Commons

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Articles 1 - 4 of 4

Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

Coupling Between Cytoplasmic Concentration Gradients Through Local Control Of Protein Mobility In The Caenorhabditis Elegans Zygote, Youjun Wu, Huaiying Zhang, Erik E. Griffin Jun 2015

Coupling Between Cytoplasmic Concentration Gradients Through Local Control Of Protein Mobility In The Caenorhabditis Elegans Zygote, Youjun Wu, Huaiying Zhang, Erik E. Griffin

Open Dartmouth: Peer-reviewed articles by Dartmouth faculty

Cell polarity is characterized by the asymmetric distribution of factors at the cell cortex and in the cytoplasm. Although mechanisms that establish cortical asymmetries have been characterized, less is known about how persistent cytoplasmic asymmetries are generated. During the asymmetric division of the Caenorhabditis elegans zygote, the PAR proteins orchestrate the segregation of the cytoplasmic RNA-binding proteins MEX-5/6 to the anterior cytoplasm and PIE-1, POS-1, and MEX-1 to the posterior cytoplasm. In this study, we find that MEX-5/6 control the segregation of GFP::PIE-1, GFP::POS-1, and GFP::MEX-1 by locally increasing their mobility in the anterior cytoplasm ...


Septin Assemblies Form By Diffusion-Driven Annealing On Membranes, Andrew A. Bridges, Huaiying Zhang, Shalin B. Mehta, Patricia Occhipinti, Tomomi Tani, Amy S. Gladfelter Feb 2014

Septin Assemblies Form By Diffusion-Driven Annealing On Membranes, Andrew A. Bridges, Huaiying Zhang, Shalin B. Mehta, Patricia Occhipinti, Tomomi Tani, Amy S. Gladfelter

Open Dartmouth: Peer-reviewed articles by Dartmouth faculty

Septins assemble into filaments and higher-order structures that act as scaffolds for diverse cell functions including cytokinesis, cell polarity, and membrane remodeling. Despite their conserved role in cell organization, little is known about how septin filaments elongate and are knitted together into higher-order assemblies. Using fluorescence correlation spectroscopy, we determined that cytosolic septins are in small complexes, suggesting that septin filaments are not formed in the cytosol. When the plasma membrane of live cells is monitored by total internal reflection fluorescence microscopy, we see that septin complexes of variable size diffuse in two dimensions. Diffusing septin complexes collide and make ...


The Filament-Forming Protein Pil1 Assembles Linear Eisosomes In Fission Yeast, Ruth Kabeche, Suzanne Baldissard, John Hammond, Louisa Howard, James B. Moseley Aug 2011

The Filament-Forming Protein Pil1 Assembles Linear Eisosomes In Fission Yeast, Ruth Kabeche, Suzanne Baldissard, John Hammond, Louisa Howard, James B. Moseley

Open Dartmouth: Peer-reviewed articles by Dartmouth faculty

The cortical cytoskeleton mediates a range of cellular activities such as endocytosis, cell motility, and the maintenance of cell rigidity. Traditional polymers, including actin, microtubules, and septins, contribute to the cortical cytoskeleton, but additional filament systems may also exist. In yeast cells, cortical structures called eisosomes generate specialized domains termed MCCs to cluster specific proteins at sites of membrane invaginations. Here we show that the core eisosome protein Pil1 forms linear cortical filaments in fission yeast cells and that purified Pil1 assembles into filaments in vitro. In cells, Pil1 cortical filaments are excluded from regions of cell growth and are ...


Minus-End Capture Of Preformed Kinetochore Fibers Contributes To Spindle Morphogenesis, Alexey Khodjakov, Lily Copenagle, Michael B. Gordon, Duane A. Compton, Tarun M. Kapoor Mar 2003

Minus-End Capture Of Preformed Kinetochore Fibers Contributes To Spindle Morphogenesis, Alexey Khodjakov, Lily Copenagle, Michael B. Gordon, Duane A. Compton, Tarun M. Kapoor

Open Dartmouth: Peer-reviewed articles by Dartmouth faculty

Near-simultaneous three-dimensional fluorescence/differential interference contrast microscopy was used to follow the behavior of microtubules and chromosomes in living alpha-tubulin/GFP-expressing cells after inhibition of the mitotic kinesin Eg5 with monastrol. Kinetochore fibers (K-fibers) were frequently observed forming in association with chromosomes both during monastrol treatment and after monastrol removal. Surprisingly, these K-fibers were oriented away from, and not directly connected to, centrosomes and incorporated into the spindle by the sliding of their distal ends toward centrosomes via a NuMA-dependent mechanism. Similar preformed K-fibers were also observed during spindle formation in untreated cells. In addition, upon monastrol removal, centrosomes established ...