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Full-Text Articles in Life Sciences

Agswe1p Regulates Mitosis In Response To Morphogenesis And Nutrients In Multinucleated Ashbya Gossypii Cells, Hanspeter Helfer, Amy S. Gladfelter Aug 2006

Agswe1p Regulates Mitosis In Response To Morphogenesis And Nutrients In Multinucleated Ashbya Gossypii Cells, Hanspeter Helfer, Amy S. Gladfelter

Dartmouth Scholarship

Nuclei in the filamentous, multinucleated fungus Ashbya gossypii divide asynchronously. We have investigated what internal and external signals spatially direct mitosis within these hyphal cells. Mitoses are most common near cortical septin rings found at growing tips and branchpoints. In septin mutants, mitoses are no longer concentrated at branchpoints, suggesting that the septin rings function to locally promote mitosis near new branches. Similarly, cells lacking AgSwe1p kinase (a Wee1 homologue), AgHsl1p (a Nim1-related kinase), and AgMih1p phosphatase (the Cdc25 homologue that likely counteracts AgSwe1p activity) also have mitoses distributed randomly in the hyphae as opposed to at branchpoints. Surprisingly, however, …


Nanosecond Pulsed Electric Field Effects On Cell Cycle And Apoptosis, Emily H. Hall Apr 2006

Nanosecond Pulsed Electric Field Effects On Cell Cycle And Apoptosis, Emily H. Hall

Theses and Dissertations in Biomedical Sciences

Apoptosis, programmed cell death, is a highly regulated and complex pathway essential for embryonic development, immune-system function and maintenance of tissue homeostasis where cells induce their own cell death. Cells undergoing apoptosis exhibit a distinctive phenotype characterized by maintenance of membrane integrity, cell shrinkage, phosphatidylserine (PS) externalization at the plasma membrane, caspase protease activation, DNA fragmentation, release of cytochrome c from the mitochondrion, and membrane blebbing. An important regulatory protein in the apoptotic pathway is p53. The p53 protein functions to modulate the cell cycle by arresting cells in the G1 and G 2 phases to repair DNA damage, and/or …


Direct Control Of Cell Cycle Gene Expression By Proto-Oncogene Product Actr, And Its Autoregulation Underlies Its Transforming Activity, Maggie C. Louie, Alexey S. Revenko, June X. Zou, Jennifer Yao, Hong-Wu Chen Jan 2006

Direct Control Of Cell Cycle Gene Expression By Proto-Oncogene Product Actr, And Its Autoregulation Underlies Its Transforming Activity, Maggie C. Louie, Alexey S. Revenko, June X. Zou, Jennifer Yao, Hong-Wu Chen

Collected Faculty and Staff Scholarship

ACTR (also called AIB1 and SRC-3) was identified as a coactivator for nuclear receptors and is linked to multiple types of human cancer due to its frequent overexpression. However, the molecular mechanism of ACTR oncogenicity and its function independent of nuclear receptors remain to be defined. We demonstrate here that ACTR is required for both normal and malignant human cells to effectively enter S phase. RNA interference-mediated depletion and chromatin immunoprecipitation assays show that endogenous ACTR directly controls the expression of genes important for initiation of DNA replication, which include cdc6, cdc25A, MCM7, cyclin E, and Cdk2. Moreover, consistent with …