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Articles 31 - 37 of 37

Full-Text Articles in Cell Biology

An Asymmetric Jam2/Par Complex Renews Muscle Stem Cells By Localized P38alpha/Beta Mapk Signaling, Andrew A. Troy Jan 2011

An Asymmetric Jam2/Par Complex Renews Muscle Stem Cells By Localized P38alpha/Beta Mapk Signaling, Andrew A. Troy

Molecular, Cellular, and Developmental Biology Graduate Theses & Dissertations

Skeletal muscle is maintained and repaired by satellite cells. Satellite cells are quiescent in uninjured muscle but activate, proliferate and repair the muscle after injury. The quiescent satellite cell population is renewed during the injury repair, but how and when this happens is unclear. Recently, several subpopulations of satellite cells have been described with an enhanced capacity for self-renewal raising the possibility that there is a subset of satellite cells dedicated to maintaining the quiescent satellite cell population. I find that all satellite cells activate in response to injury and, after the first division, quiescent satellite cells reappear. I show ...


Regulation Of Escrt-Iii Assembly And Membrane Scission Activity In The Budding Yeast Saccharomyces Cerevisiae, Megan Anne Wemmer Jan 2011

Regulation Of Escrt-Iii Assembly And Membrane Scission Activity In The Budding Yeast Saccharomyces Cerevisiae, Megan Anne Wemmer

Molecular, Cellular, and Developmental Biology Graduate Theses & Dissertations

The sequential recruitment and assembly of endosomal sorting complexes required for transport (ESCRTs) at the endosomal membrane mediate the selection and clustering of cargoes into vesicles that bud into the lumen of the endosome. In addition to regulating this sorting process at endosomes, in mammalian cells ESCRTs are additionally required for the budding of many types of enveloped viruses, as well as the separation of cells during cytokinesis. These processes share a topologically similar membrane scission event facilitated by regulated ESCRT-III assembly at the cytoplasmic surface of the membrane to promote the formation and scission of internal vesicles. The Snf7 ...


How Reticulon Gets The Er Into Shape, Nesia A. Zurek Jan 2011

How Reticulon Gets The Er Into Shape, Nesia A. Zurek

Molecular, Cellular, and Developmental Biology Graduate Theses & Dissertations

The endoplasmic reticulum (ER) is an organelle that extends throughout the cell cytoplasm and has a complex membrane structure. There are three major ER domains, the nuclear envelope, the ER cisternae, and the tubular ER. Each domain is structured by its own set of membrane shaping proteins. The protein family that is the focus of this study is the reticulons. The reticulons generate curvature throughout the ER, specifically at the tubular ER and the edges of ER cisternae. All reticulons tested partition exclusively to high curvature ER and generate immobile oligomers. Every reticulon contains the reticulon homology domain (RHD) at ...


Cardiac Atrophy Due To Cancer: Characterization, Mechanisms, And Sex Differences, Pippa Froukje Cosper Jan 2011

Cardiac Atrophy Due To Cancer: Characterization, Mechanisms, And Sex Differences, Pippa Froukje Cosper

Molecular, Cellular, and Developmental Biology Graduate Theses & Dissertations

Approximately one-third of cancer deaths are caused by cachexia, a severe form of skeletal muscle and adipose tissue wasting that affects men more than women. The heart also undergoes atrophy in cancer patients but the extent, functional consequences, mechanisms and sex differences have not been elucidated. In a mouse colon-adenocarcinoma model, cancer causes a loss of cardiac mass due to a decrease in cardiac myocyte size that is associated with reduced levels of all sarcomeric proteins. I provide evidence that published reports showing a selective decrease in myosin heavy chain (MyHC) during cancer cachexia are likely an artifact resulting from ...


Investigating The Components And Assembly Of Processing Bodies In Human Cells, Jaclyn Rose Dennis Jan 2011

Investigating The Components And Assembly Of Processing Bodies In Human Cells, Jaclyn Rose Dennis

Molecular, Cellular, and Developmental Biology Graduate Theses & Dissertations

Messenger RNA degradation is important for the control of gene expression. The major mRNA decay pathway requires the coordination of proteins involved in deadenylation, decapping, and exonucleolysis to function properly. Interestingly, many of those proteins, as well as translationally repressed mRNAs, localize to discreet cytoplasmic foci called processing bodies (PBs). It remains unclear how PBs form and their functional significance is, as yet, unknown. To better understand how PB assembly may be regulated, I tested whether the cytoskeleton is required for PB dynamics in human cells. I found that the cytoskeleton is likely not required for overall PB assembly, integrity ...


An Analysis Of Latent Membrane Protein-1 Signaling Complexes And Their Contribution To Epstein-Barr Virus Infection, Ryan Akira Takeshita Jan 2011

An Analysis Of Latent Membrane Protein-1 Signaling Complexes And Their Contribution To Epstein-Barr Virus Infection, Ryan Akira Takeshita

Molecular, Cellular, and Developmental Biology Graduate Theses & Dissertations

In immunocompromised individuals, B cells infected with Epstein-Barr virus often display tumorigenic growth. One of the viral oncoproteins that contributes to this transformation is the latent membrane protein-1 (LMP-1), which constitutively mimics the signaling of ligand-dependent CD40, a tumor necrosis factor receptor. The experiments described in this dissertation were designed to elucidate the molecular mechanisms that underlie LMP-1's signaling potential. We investigated the relationships between LMP-1's subcellular localization, homo-oligomerization, comigration with detergent-resistant membranes, and its signaling outputs in order to bridge some of the gaps standing in the way of a unified theory of LMP-1 function. The data ...


Characterization Of Caspase Regulation And Hepatitis B Virus Induced Cell Death In The Nematode Caenorhabditis Elegans, Xin Geng Jan 2011

Characterization Of Caspase Regulation And Hepatitis B Virus Induced Cell Death In The Nematode Caenorhabditis Elegans, Xin Geng

Molecular, Cellular, and Developmental Biology Graduate Theses & Dissertations

The nematode Caenorhabditis elegans has become a successful animal model for biomedical research, particularly in studying mechanisms of cell death and human disease. The conservation of critical biological pathways between C. elegans and higher organisms, together with the simplicity and cost-effectiveness of cultivation, make for an effective in vivo animal model that is amenable to genetic dissection and pharmacological manipulation. My thesis describes how I used C. elegans as an animal model to advance our understanding of caspase regulation and HBV pathogenesis.

First I report that inactivation of the C. elegans csp-3 and csp-2 genes, which encode two proteins similar ...