This proposal is directed to an important but very poorly understood mechanism of gene control, the targeted degradation of short-lived cytokine and proto-oncogene mRNAs in mammalian cells, which is promoted by an A+U-rich element (ARE) in the 3' untranslated region (3'UTR) of these mRNAs. This renewal application builds on our work during the previous project period and seeks to characterize the function of one ARE-binding protein known as AUF1, which promotes rapid decay of ARE-mRNAs.
Aim 1 will identify and characterize new AUF1 interacting proteins by mass spectrometry, verify interactions in vivo, and investigate the functional importance of these interactions in ARE-mRNA decay. Only several of the AUFl-interacting proteins have been identified to date. Since AUF1 lacks enzymatic activity, it is through interactions with other proteins that AUF1 facilitates or regulates decay of cytokine and proto-oncogene ARE-mRNAs.
Aim 2 will analyze the function of AUF1 in promoting or regulating the rapid turnover of endogenous and reporter ARE-mRNAs in isolated primary mouse spleen and thymus lymphocytic cells, where AUF1 is predominantly expressed. Our recent development of an AUF1 knockout mouse, and studies which localized AUF1 expression largely to splenic and thymic lymphocytes, makes it possible to investigate the molecular and biochemical functions of AUF1 in its authentic expressing cell type and organ.
Aim 3 will characterize the function of AUF1 in the mouse. There is little if any understanding of the role of AUF1 in animals. By comparing wild type and AUF1 knockout mice, studies will investigate the function of AUF1 in promoting or regulating the stability of lymphocytic cytokine mRNAs in the thymus and spleen. Studies will also examine the phenotype of the AUF1 knockout mouse in different relevant experimental settings.
|Chenette, Devon M; Cadwallader, Adam B; Antwine, Tiffany L et al. (2016) Targeted mRNA Decay by RNA Binding Protein AUF1 Regulates Adult Muscle Stem Cell Fate, Promoting Skeletal Muscle Integrity. Cell Rep 16:1379-1390|
|Sadri, Navid; Schneider, Robert J (2009) Auf1/Hnrnpd-deficient mice develop pruritic inflammatory skin disease. J Invest Dermatol 129:657-70|
|Ramirez-Valle, Francisco; Braunstein, Steve; Zavadil, Jiri et al. (2008) eIF4GI links nutrient sensing by mTOR to cell proliferation and inhibition of autophagy. J Cell Biol 181:293-307|
|Lu, Jin-Yu; Sadri, Navid; Schneider, Robert J (2006) Endotoxic shock in AUF1 knockout mice mediated by failure to degrade proinflammatory cytokine mRNAs. Genes Dev 20:3174-84|
|He, Cheng; Schneider, Robert (2006) 14-3-3sigma is a p37 AUF1-binding protein that facilitates AUF1 transport and AU-rich mRNA decay. EMBO J 25:3823-31|
|Lu, Jin-Yu; Bergman, Naomi; Sadri, Navid et al. (2006) Assembly of AUF1 with eIF4G-poly(A) binding protein complex suggests a translation function in AU-rich mRNA decay. RNA 12:883-93|
|Lu, Jin-Yu; Schneider, Robert J (2004) Tissue distribution of AU-rich mRNA-binding proteins involved in regulation of mRNA decay. J Biol Chem 279:12974-9|
|Sarkar, Bedabrata; Xi, Qiaoran; He, Cheng et al. (2003) Selective degradation of AU-rich mRNAs promoted by the p37 AUF1 protein isoform. Mol Cell Biol 23:6685-93|
|Sarkar, Bedabrata; Lu, Jin-Yu; Schneider, Robert J (2003) Nuclear import and export functions in the different isoforms of the AUF1/heterogeneous nuclear ribonucleoprotein protein family. J Biol Chem 278:20700-7|
|Laroia, Gaurav; Schneider, Robert J (2002) Alternate exon insertion controls selective ubiquitination and degradation of different AUF1 protein isoforms. Nucleic Acids Res 30:3052-8|
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