The cyclin E protein controls the transition from the G1 to the S-phase of the cell cycle. Deregulated cyclin E activity causes abnormal cell division, and mutations leading to aberrant cyclin E-cdk2 regulation are found in most human cancers. The research described in this proposal seeks to understand the mechanisms that govern cyclin E in normal cells and tumors. We are particularly interested in the regulation and function of cyclin E phosphorylation in cell cycle control and tumorigenesis. Multiple site-specific phosphorylations control cyclin E, but the role of specific mitogenic and signal transduction pathways in regulating these phosphorylations is unknown. The goal of the first aim is to characterize the regulation of cyclin E phosphorylation in normal cells and in tumor cells. We will develop antibodies that recognize phosphorylated forms of cyclin E, and these reagents will be used to examine cyclin E phosphorylation in normal cells, and to determine if it is abnormal in tumor cells. We are particularly interested in the relationships between phosphorylated cyclin E and the Fbw7 ubiquitin ligase. Because most studies on cyclin E phosphorylation have utilized overexpressed cyclin E, it has been difficult to distinguish the role of phosphorylation from the consequences of overexpression. We will thus use """"""""knock-in"""""""" models in which phosphorylation sites are mutated in the context of the endogenous cyclin E locus to study the function of specific phosphorylations. These studies will use homologous recombination techniques in mice, as well as develop new methods based on adeno-associated virus vectors in human cells. The latter method may be broadly applicable to studies of protein phosphorylation in systems where mouse models are unnecessary or undesirable. The mechanisms of cyclin E-associated tumorigenesis are largely unknown. The overall goal of this aim is to use cyclin E transgenic and knock-in strains to develop models of cyclin E-associated cancer. Because we have discovered a homeostatic p53-dependent response that restrains excess cyclin E activity, we will specifically test the hypothesis that loss of p53 function is an integral step in the development of tumors with deregulated cyclin E expression. These models will be used to study the mechanisms of cyclin E-associated tumorigenesis and may facilitate the development of new therapeutic strategies. ? ?

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA102742-02
Application #
6767695
Study Section
Cell Development and Function Integrated Review Group (CDF)
Program Officer
Spalholz, Barbara A
Project Start
2003-07-01
Project End
2008-06-30
Budget Start
2004-07-01
Budget End
2005-06-30
Support Year
2
Fiscal Year
2004
Total Cost
$384,925
Indirect Cost
Name
Fred Hutchinson Cancer Research Center
Department
Type
DUNS #
078200995
City
Seattle
State
WA
Country
United States
Zip Code
98109
Davis, Ryan J; Welcker, Markus; Clurman, Bruce E (2014) Tumor suppression by the Fbw7 ubiquitin ligase: mechanisms and opportunities. Cancer Cell 26:455-64
Welcker, Markus; Larimore, Elizabeth A; Swanger, Jherek et al. (2013) Fbw7 dimerization determines the specificity and robustness of substrate degradation. Genes Dev 27:2531-6
Hughes, Bridget T; Sidorova, Julia; Swanger, Jherek et al. (2013) Essential role for Cdk2 inhibitory phosphorylation during replication stress revealed by a human Cdk2 knockin mutation. Proc Natl Acad Sci U S A 110:8954-9
Davis, Michael A; Larimore, Elizabeth A; Fissel, Brian M et al. (2013) The SCF-Fbw7 ubiquitin ligase degrades MED13 and MED13L and regulates CDK8 module association with Mediator. Genes Dev 27:151-6
Hizli, Asli A; Chi, Yong; Swanger, Jherek et al. (2013) Phosphorylation of eukaryotic elongation factor 2 (eEF2) by cyclin A-cyclin-dependent kinase 2 regulates its inhibition by eEF2 kinase. Mol Cell Biol 33:596-604
Grim, Jonathan E; Knoblaugh, Sue E; Guthrie, Katherine A et al. (2012) Fbw7 and p53 cooperatively suppress advanced and chromosomally unstable intestinal cancer. Mol Cell Biol 32:2160-7
Welcker, Markus; Larimore, Elizabeth A; Frappier, Lori et al. (2011) Nucleolar targeting of the fbw7 ubiquitin ligase by a pseudosubstrate and glycogen synthase kinase 3. Mol Cell Biol 31:1214-24
Kuppers, Daniel A; Hwang, Harry C; Jackson, Aimee L et al. (2011) Effect of Xpcl1 activation and p27(Kip1) loss on gene expression in murine lymphoma. PLoS One 6:e14758
Sengupta, Tanushri; Abraham, Gathi; Xu, Yanfei et al. (2011) Hypoxia-inducible factor 1 is activated by dysregulated cyclin E during mammary epithelial morphogenesis. Mol Cell Biol 31:3885-95
Chi, Yong; Clurman, Bruce E (2010) Mass spectrometry-based identification of protein kinase substrates utilizing engineered kinases and thiophosphate labeling. Curr Protoc Chem Biol 2:

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