title: The proteasome activator PA28γ, a negative regulator of p53, is transcriptionally up-regulated by p53.
abstract: PA28γ (also called REGγ, 11Sγ or PSME3) negatively regulates p53 activity by promoting its nuclear export and/or degradation. Here, using the RNA ligase-mediated rapid amplification of cDNA ends (RLM-RACE) method, we identified the transcription start site of the PA28γ gene. Assessment with the luciferase assay demonstrated that the sequence -193 to +16 is the basal promoter. Three p53 binding sites were found within the PA28γ promoter utilizing a bioinformatics approach and were confirmed by chromatin immunoprecipitation and biotinylated DNA affinity precipitation experiments. The p53 protein promotes PA28γ transcription, and p53-stimulated transcription of PA28γ can be inhibited by PA28γ itself. Our results suggest that PA28γ and p53 form a negative feedback loop, which maintains the balance of p53 and PA28γ in cells.
authors: Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Science, Hunan Normal University, Changsha 410081, China. wanzhenxing88@gmail.com.
authors: Zhen-Xing
authors: ZX
authors: Wan
authors: Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Science, Hunan Normal University, Changsha 410081, China. ydmumina@gmail.com.
authors: Dong-Mei
authors: DM
authors: Yuan
authors: Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Science, Hunan Normal University, Changsha 410081, China. zhuo715467375@gmail.com.
authors: Yi-Ming
authors: YM
authors: Zhuo
authors: Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Science, Hunan Normal University, Changsha 410081, China. lefewy.yixin@gmail.com.
authors: Xin
authors: X
authors: Yi
authors: Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Science, Hunan Normal University, Changsha 410081, China. zhoujihnu@gmail.com.
authors: Ji
authors: J
authors: Zhou
authors: Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Science, Hunan Normal University, Changsha 410081, China. xuzaoxu@gmail.com.
authors: Zao-Xu
authors: ZX
authors: Xu
authors: Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Science, Hunan Normal University, Changsha 410081, China. jlzhou@hunnu.edu.cn.
authors: Jian-Lin
authors: JL
authors: Zhou
mesh_terms: D001324:Autoantigens / Q000235:genetics / Q000378:metabolism*; D057809:HEK293 Cells; D006801:Humans; D011401:Promoter Regions, Genetic; D046988:Proteasome Endopeptidase Complex / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D034622:RNA Interference; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology; D020218:Response Elements / Q000235:genetics; D014158:Transcription, Genetic; D016159:Tumor Suppressor Protein p53 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D001324:Autoantigens; C099558:Ki antigen; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D011994:Recombinant Proteins; D016159:Tumor Suppressor Protein p53; D046988:Proteasome Endopeptidase Complex