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Full-Text Articles in Life Sciences
The Role Of The Diras Family Members In Regulating Ras Function, Cancer Growth And Autophagy, Margie Nicole Sutton
The Role Of The Diras Family Members In Regulating Ras Function, Cancer Growth And Autophagy, Margie Nicole Sutton
Dissertations & Theses (Open Access)
DIRAS3 is a maternally imprinted tumor suppressor gene that is downregulated by multiple mechanisms across several tumor types. When re-expressed, DIRAS3 decreases proliferation, inhibits motility, and induces autophagy and tumor dormancy. DIRAS3 encodes a 26 kDa small GTPase with 60% homology to Ras and Rap, differing from oncogenic Ras family members by a 34-amino acid N-terminal extension that is required for its tumor suppressive function in ovarian cancer. By assessing the structure-function relationship, I found that DIRAS3 inhibits Ras-induced transformation and is a natural antagonist of Ras/MAPK signaling. DIRAS3 binds directly to Ras and disrupts cluster formation inhibiting the activation …
Novel Posttranslational Modification In Lkb1 Activation And Function, Szu-Wei Lee
Novel Posttranslational Modification In Lkb1 Activation And Function, Szu-Wei Lee
Dissertations & Theses (Open Access)
Cancer cells display dramatic alterations in cellular metabolism to meet their needs of increased growth and proliferation. In the last decade, cancer research has brought these pathways into focus, and one emerging issue that has come to attention is that many oncogenes and tumor-suppressors are intimately linked to metabolic regulation (Jones and Thompson, 2009). One of the key tumor-suppressors involved in metabolism is Liver Kinase B1 (LKB1). LKB1 is the major upstream kinase of the evolutionarily conserved metabolic sensor—AMP-activated protein kinase (AMPK). Activation of the LKB1/AMPK pathway provides a survival advantage for cells under energy stress. LKB1 forms a heterotrimeric …
Increased Geranylgeranylated K-Ras Contributes To Antineoplastic Effects Of Farnesyltransferase Inhibitors., Mandy A. Hall
Increased Geranylgeranylated K-Ras Contributes To Antineoplastic Effects Of Farnesyltransferase Inhibitors., Mandy A. Hall
Dissertations & Theses (Open Access)
The Ras family of small GTPases (N-, H-, and K-Ras) is a group of important signaling mediators. Ras is frequently activated in some cancers, while others maintain low level activity to achieve optimal cell growth. In cells with endogenously low levels of active Ras, increasing Ras signaling through the ERK and p38 MAPK pathways can cause growth arrest or cell death. Ras requires prenylation – the addition of a 15-carbon (farnesyl) or 20-carbon (geranylgeranyl) group – to keep the protein anchored into membranes for effective signaling. N- and K-Ras can be alternatively geranylgeranylated (GG’d) if farnesylation is inhibited but are …