Our search for RING finger proteins that share homology with RING domains of c-Cbl, BRCAI and Mdm2 led us to identify RNF-5 in C. elegans. Over expression and inhibition of RNF5 pointed to the role of RNF-5 in C. elegan's growth, development and response to stress. RNF-5, exhibit ubiquitin Iigase activity in vitro and are subject to extensive ubiquitination in vivo, suggesting that RNF-5 is involved in regulation of protein stability and/or trafficking. A yeast 2-hybrid screen identified paxillin, as RNF-5 associated protein. Paxillin functions as a scaffold for the recruitment of molecules into a signal transduction complex important in processing of external stimuli that modulate cell adhesion, motility and growth control. We have confirmed RNF-5's association with, and ubiquitination of, paxillin, suggesting that RNF-5 is playing important role in the regulation of paxillin. Furthermore, Northern of primary human tumors revealed decreased RNF-5 expression in colon and renal cancer; co-expression of RNF-5 with Ras blocked Ras-mediated in vitro transformation of NIH3T3 cells -implicating RNF-5 in tumorigenesis. These observations provide strong support for the hypothesis that RNF-5 plays an important role in cell growth and development as well as in transformation processes. The proposed studies aim at comprehensive characterization of RNF-5's as follows: (1). Determine the pattern and regulation of RNF-5 expression before and after exposure to various forms of stress. (2). Characterize the regulation of RNF-5's stability and the role of protein kinases in RNF-5 expression, localization and E3 ligase activities (3). Assess the role of RN F-S in the regulation of paxillin localization, stability and function. The implications of such changes for focal adhesion and growth factor signaling under normal and stressed conditions will be determined.(4) Determine changes in RNF-5 genomic sequence and expression in transformed cultures and in primary tumors (at the level of DNA, RNA and protein) (5). Use C. elegans to identify the upstream and downstream components of RNF-5 in the regulation of dauer formation and growth control. The functional significance of the RNF-5- paxillin interaction will also be assessed. Overall, successful completion of the proposed studies will establish the role of RNF-5 in normal cell maintenance, the stress response. development and Progression of human cancer.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA097105-02
Application #
6637813
Study Section
Special Emphasis Panel (ZRG1-PTHB (04))
Program Officer
Mietz, Judy
Project Start
2002-07-01
Project End
2004-06-30
Budget Start
2003-07-01
Budget End
2004-06-30
Support Year
2
Fiscal Year
2003
Total Cost
$339,424
Indirect Cost
Name
Mount Sinai School of Medicine
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
078861598
City
New York
State
NY
Country
United States
Zip Code
10029
Jeon, Young Joo; Khelifa, Sihem; Ratnikov, Boris et al. (2015) Regulation of glutamine carrier proteins by RNF5 determines breast cancer response to ER stress-inducing chemotherapies. Cancer Cell 27:354-69
Kuang, Ersheng; Qi, Jianfei; Ronai, Ze'ev (2013) Emerging roles of E3 ubiquitin ligases in autophagy. Trends Biochem Sci 38:453-60
Kuang, Ersheng; Okumura, Cheryl Y M; Sheffy-Levin, Sharon et al. (2012) Regulation of ATG4B stability by RNF5 limits basal levels of autophagy and influences susceptibility to bacterial infection. PLoS Genet 8:e1003007
Chen, Meifan; Gutierrez, Gustavo J; Ronai, Ze'ev A (2011) Ubiquitin-recognition protein Ufd1 couples the endoplasmic reticulum (ER) stress response to cell cycle control. Proc Natl Acad Sci U S A 108:9119-24
Tcherpakov, Marianna; Delaunay, Agnes; Toth, Julia et al. (2009) Regulation of endoplasmic reticulum-associated degradation by RNF5-dependent ubiquitination of JNK-associated membrane protein (JAMP). J Biol Chem 284:12099-109
Tcherpakov, Marianna; Broday, Limor; Delaunay, Agnes et al. (2008) JAMP optimizes ERAD to protect cells from unfolded proteins. Mol Biol Cell 19:5019-28
Delaunay, Agnes; Bromberg, Kenneth D; Hayashi, Yukiko et al. (2008) The ER-bound RING finger protein 5 (RNF5/RMA1) causes degenerative myopathy in transgenic mice and is deregulated in inclusion body myositis. PLoS One 3:e1609
Broday, Limor; Hauser, Craig A; Kolotuev, Irina et al. (2007) Muscle-epidermis interactions affect exoskeleton patterning in Caenorhabditis elegans. Dev Dyn 236:3129-36
Bromberg, Kenneth D; Kluger, Harriet M; Delaunay, Agnes et al. (2007) Increased expression of the E3 ubiquitin ligase RNF5 is associated with decreased survival in breast cancer. Cancer Res 67:8172-9
Kadoya, Takayuki; Khurana, Ashwani; Tcherpakov, Marianna et al. (2005) JAMP, a Jun N-terminal kinase 1 (JNK1)-associated membrane protein, regulates duration of JNK activity. Mol Cell Biol 25:8619-30

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