rna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控

1、rna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控rna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控第1頁(yè)mRNA turnover Translation level Post-translation levelTranscription levelGene RegulationDNA and chromatin levelsPost-transcriptional levelMaturation mRNA export rna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控第2頁(yè)Regulatory factors for mRNA decay and translation RNA binding proteins microRNAs rna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控

2、第3頁(yè)RNA binding proteins (RBPs) RNA結(jié)合蛋白種類(lèi)很多，預(yù)計(jì)占細(xì)胞編碼蛋白6-8%者為RNA結(jié)合蛋白, 但迄今只有為數(shù)不多幾個(gè)RNA結(jié)合蛋白（如HuR，AUF1，TTP，TIA1，CUGBP2等）被證實(shí)可特異參加mRNA穩(wěn)定性、翻譯、或其它層面基因調(diào)控。 rna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控第4頁(yè)HuR Hu /ELAV RNA 結(jié)合蛋白家族（包含HuA/HuR，Hel-N1，HuC，HuD） 主要組員。與其它組員僅表示于神經(jīng)細(xì)胞不一樣，HuR幾乎在全部組織 都有表示。主要位于細(xì)胞核，但可穿梭于細(xì)胞漿/核間，且只有細(xì)胞漿HuR 可調(diào)控mRNA穩(wěn)定性（及翻譯）。核內(nèi)HuR則與

3、mRNA成熟及export相關(guān)。 結(jié)合全部三類(lèi)AREs。結(jié)合后結(jié)局主要為穩(wěn)定目標(biāo)。所以也被 稱(chēng)為mRNA 穩(wěn)定因子。 結(jié)合并穩(wěn)定VEGF, COX-2, p21, cyclin A, cyclin B1, c-fos, TNF ，IL-1， MyoD，Myogenin，bcl-2等mRNA。所以可調(diào)整應(yīng)激反應(yīng)，細(xì)胞周期，腫瘤， 分化，調(diào)亡等過(guò)程。 HuR也可結(jié)合目標(biāo)并調(diào)整其翻譯。 1）調(diào)控翻譯效率， 如 p53，p27 mRNA, c-myc。 2）調(diào)控mRNA export, 如 CD83，c-fos, COX-2。rna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控第5頁(yè)AUF1 也叫HnRNPD（heteroge

4、neous nuclear ribonucleoprotein D).主要位于核內(nèi)，但可穿梭于核/細(xì)胞漿間，結(jié)合I，II類(lèi)AREs。結(jié)合目標(biāo)mRNA 后使之不穩(wěn)定（易于降解），如P21， CyclinD1，也可使目標(biāo)穩(wěn)定，如TNF-alpha。rna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控第6頁(yè)TTP與HuR及AUF1不一樣，TTP主要位于細(xì)胞漿，結(jié)合II類(lèi)AREs。結(jié)合目標(biāo)后主要使目標(biāo)不穩(wěn)定。如：COX-2，TNF-alpha,GM-CSF,等。rna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控第7頁(yè) Effect of ARE-BPs on the stability and translation of ARE-containin

5、g mRNAsARE-BPs mRNA stability Protein expression Translational efficiency Abundance Increase Decrease Increase Decrease Up regulated Down regulated AUF1 c-myc (42) c-myc (46) GMCSF (55) c-fos (42,67) c-fos (53) IL-3 (55) PTH (56) p21 (48) GMCSF (42) Cyclin D1 (48) TNF-alpha (42) GMCSF (53,54) IL-3 (

6、55) HuR c-fos(59,63,67) p53(99,137) TNF-alpha (139) p21 (69) TNF-alpha (139) MyoD (68) Cox-2 (139) Cyclin A (70) p21 (48,68,69) Cyclin B1 (70) Cyclin A (70) NOS II/iNOS (64) Cyclin B1 (70) GMCSF (55) Cyclin D1 (48) Cox-2 (71,173) NOS II/iNOS (64) IL-3 (55) GMCSF (59) VEGF (173) TNF-alpha (65,74,139)

7、 p53 (99,137) Cox-2 (71,139) IL-3 (55,66) VEGF (62) Myogenin (68)Hel-N1 TNF-alpha (74) NF-M (73) NF-M (73) GLUT1 (72) GLUT1 (72) GLUT1 (72)HuD GAP-43 (7577) GAP-43 (75,76)TTP c-fos (90) GMCSF (81) GMCSF (18,81,8385,91) TNF-alpha (80) TNF-alpha (18,81,8386,89,90) IL-2 (82) Cox-2 (87) IL-3 (88) IL-2 (

8、82,90) IL-3 (18,66,83,84,88)BRF1 TNF-alpha (89,93) GMCSF (55) IL-3 (55,92,93) IL-3 (55)TIA-1 TNF-alpha (120) TNF-alpha (120) Cox-2 (121) Cox-2 (121) KSRP c-fos (90,93) NOS II/iNOS (102) NOS II/iNOS (102) TNF-alpha (90,93) IL-2 (90,93) c-jun (93)CUG-BP2 Cox-2 (150) Cox-2 (150) Cox-2 (150) Nucleolin b

9、cl-2 (175)TINO bcl-2 (176) PAIP2 VEGF (177) VEGF (177)rna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控第8頁(yè)Interaction of the factors involving in post-transcriptional regulation1. RNA結(jié)合蛋白相互作用。如， HuR與AUF1均可結(jié)合于p21 與cyclin D1 3UTR， 但二者有競(jìng)爭(zhēng)，且功效相反。2. RNA結(jié)合蛋白與microRNA間相互作用。如， HuR與let-7, miR-122, TTP與miR-16 。rna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控第9頁(yè)AU-rich Elements (

10、AREs)1.主要指位于3-非翻譯區(qū)富含AU序列。2. 被RNA結(jié)合蛋白識(shí)別，結(jié)合。3. 主要為mRNA 不穩(wěn)定元件，是mRNA 在完成使命后快速降解結(jié)構(gòu)基礎(chǔ)。4. 依組成份為三類(lèi)1）含1-5個(gè)分散AUUUA。2）最少有兩個(gè)Overlapping UUAUUUA(U/A)(U/A). 依AUUUA重復(fù)方式分為5類(lèi)，IIA，IIB，IIC，等。3）富含U，但無(wú)AUUUA。注： 除一級(jí)結(jié)構(gòu)外， mRNA二級(jí)結(jié)構(gòu)也與RNA-蛋白質(zhì)相互作用親密相關(guān)。 如，約70-80% HuR或AUF1結(jié)合序列含有相同二級(jí)結(jié)構(gòu)rna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控第10頁(yè)mRNAs ARE-BPsClass Motif Exam

11、ples I 1 to 5個(gè)散在 AUUUA c-myc AUF1 , HuR ，Hel-N1， HuC， HuD， AUH，GAPDH，Hsp70 c-fos AUF1，HuR， Hel-N1， HuD ，KSRP，AUH Beta1-AR AUF1 PTH AUF1 Interferon-gamma GAPDH，Hsp70 MyoD HuR p21 AUF1， HuR， HuD Cyclin A HuR Cyclin B1 HuR Cyclin D1 AUF1，HuR PAI-2 HuR NOS II/iNOS HuR， KSRPIIA (AUUU)5A GMCSF AUF1， HuR，

12、Hel-N1， TTP， BRF1， TIAR，KSRP，AUH，GAPDH，Hsp70，hnRNP-A1， hnRNP-C TNF-alpha AUF1，HuR， TTP， BRF1，TIA-1， TIAR，KSRPIIB(AUUU)4A Interferon-alpha hnRNP-A1， hnRNP-A2, hnRNP-A3IIC(A/U)(AUUU)3A(A/U) Cox-2 AUF1, HuR, HuD, TTP, TIA-1, TIAR, hnRNP-A1， hnRNP-A2, hnRNP-A3，CUDBP2 IL-2 AUF1， HuR， HuD， TTP。Hsp70， Hsp1

13、10， hnRNP-A1 IL-3 HuR， BEF1， AUH，Nucleolin，TINO bcl-2 AUF1， HuR， VEGF HuR HuC， HuD，PAIP2IIINo AUUUA, c-jun TIAR，CUGBP1 U-rich region GLUT1 Hel-N1，hnRNP-A2， hnRNP-L p53 HuR， Id Hel-N1 hsp70 HuR Myogenin HuR NF-M Hel-N1 GAP-43 HuD A matrix presentation has been used to represent the identified associa

14、tions between ARE-BPs and ARE-containing mRNAs. The mRNAs containing identified functional AREs are listed vertically and are grouped according to the classifications proposed by (24) and (26). The ARE-BPs are displayed horizontally. Where appropriate the different names used to denote the same prot

15、ein or mRNA are given. The lists of ARE-containing mRNAs and of ARE-BPs are not exhaustive and only direct interactions have been considered. Where the experimental methods used identified endogenous interactions, these are indicated by an asterisk. Data on the experimental methods are presented in

16、the Supplementary data. Numbers correspond to listed references.Interaction between ARE and RBPsrna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控第11頁(yè)RNA-蛋白質(zhì)相互作用(結(jié)合)特點(diǎn)可在細(xì)胞核, 也可在細(xì)胞漿發(fā)生在核與胞漿結(jié)合功效截然不一樣, 如在胞漿與翻譯及mRNA穩(wěn)定性相關(guān), 在核可能與拼接或成熟相關(guān).RNA結(jié)合蛋白對(duì)目標(biāo)序列要求不如DNA 結(jié)合蛋白般嚴(yán)格.結(jié)合部位大多在3-UTR, 少數(shù)在5-UTR,絕少見(jiàn)于CDS.rna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控第12頁(yè)mRNA穩(wěn)定性（turnover）研究特殊技術(shù)蛋白質(zhì)-RNA結(jié)

17、合試驗(yàn)： 1）目標(biāo)Transcript 體外轉(zhuǎn)錄與標(biāo)識(shí) 2）細(xì)胞漿抽提物制備。 3) EMSA (gel-shift, supershift) 4) rChip, pull-down assays (using paramagnetic streptavidin dynabeads, biotinyl-labeled transcripts)mRNA半衰期測(cè)定 基礎(chǔ)思緒:終止轉(zhuǎn)錄后,收取不一樣時(shí)間點(diǎn)之RNA, 定量分析RNA降解速率. 1）用ActinomycinD終止轉(zhuǎn)錄 2）Tet-off/on （或類(lèi)似）匯報(bào)基因系統(tǒng) 3) in vitro RNA降解分析rna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控第13

18、頁(yè)Tet-on system is activated in the presence of doxycyclinethe DNA binding domain of the Tet-on regulator (rTetR) contains mutations repressor that only binds DNA in the absence of ligand is converted to a ligand-dependent DNA binding protein.RNA-polTetracycline controlled transactivator (tTA)rna結(jié)合蛋白

19、與轉(zhuǎn)錄后調(diào)控第14頁(yè)TET-OFF in detailsManfred Gossen and Hermann Bujard The Tet-off system is repressed in the presence of the doxycyclineTET-VP producing vectorGene of interest expressing vectorVP RNA pol interacting partTetR - tet binding partTET-OFF systemTetracycline controlled transactivator (tTA)如：EGFP-

20、interest target chimericrna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控第15頁(yè)mRNA 翻譯研究特用技術(shù)新生蛋白分析。Polysome 分離， Polysomal RNA, Polysomal 蛋白質(zhì)分離。其它經(jīng)典技術(shù)。 rna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控第16頁(yè)Reference Barreau, etal; Nucleic Acids Research,33(22): 7138-7150, 2) 3) Wang, et al; MCB, 20:760-769, 4) Lal, et al; EMBO J., 23:3092-3102, /departments/mmb/baranova/pag

21、es/ppt/biotech-lec5.ppt rna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控第17頁(yè)HuR Regulates p21 mRNA Stabilization by UV LightWang, et al; Mol Cell Biol. ， 20(3): 760769. 細(xì)胞暴露于各種應(yīng)激（Stresses）如short-wavelength UV light (UVC)時(shí), cyclin-dependent kinase inhibitor p21表示顯著被誘導(dǎo)。P21 調(diào)控，尤其P53調(diào)整轉(zhuǎn)錄已被廣泛，深入研究。先前研究發(fā)覺(jué)，UVC可經(jīng)過(guò)P53-不依賴(lài)方式誘導(dǎo)P21。研究還發(fā)覺(jué)，細(xì)胞暴露于UV

22、C后，p21 mRNA 穩(wěn)定性增加。問(wèn)題：UVC誘導(dǎo)P21表示（穩(wěn)定性增加）機(jī)制怎樣？ 與HuR相關(guān)否？ Background:Example rna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控第18頁(yè)UVC 輻射誘導(dǎo)蛋白-P21 RNA復(fù)合物形成。復(fù)合物形成為P53不依賴(lài)性，因?yàn)椴徽揜KO細(xì)胞是否有野生型P53，復(fù)合物形成無(wú)區(qū)分。復(fù)合物由蛋白質(zhì)與3UTR間結(jié)合而成。5UTR及缺失ARE3-UTR（A1，C5）幾乎無(wú)蛋白結(jié)合。核與細(xì)胞漿蛋白均可與P21 3UTR 形成復(fù)合物，但只有胞漿中復(fù)合物形成可被UVC誘導(dǎo)。UVC induces the formation of p213-UTR-protein complex

23、 in the cytoplasmrna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控第19頁(yè)A。復(fù)合物形成在UVC 輻射半小時(shí)后顯著被誘導(dǎo)，與P21 被誘導(dǎo)相吻合。B。 競(jìng)爭(zhēng)抑制試驗(yàn)說(shuō)明復(fù)合物特異性，Cold 探針可競(jìng)爭(zhēng)抑制復(fù)合物形成。C。 EMSA 后，UV交聯(lián)，SDS分離復(fù)合物，發(fā)覺(jué)復(fù)合物中一條大約40Kd 復(fù)合物（單一蛋白與大約10個(gè)堿基短片斷轉(zhuǎn)錄物形成），說(shuō)明有一35-40 Kd RNA結(jié)合蛋白被UVC誘導(dǎo)并與P21 3-UTR 結(jié)合。 D。 UVC 誘導(dǎo)該未知復(fù)合物趨勢(shì)與P21被誘導(dǎo)一致。Elevation of p21 by UVC is accompanied with increased format

24、ion of P21 3UTR-protein complexrna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控第20頁(yè)HuR 結(jié)合p21 mRNA（ in vivo and in vitro） (A)， (B) HuR抗體可特異結(jié)合細(xì)胞漿蛋白與B2形成復(fù)合物。(C) RNase T1 Selection Assay was carried out with B2 and A1, incubated with 10 nM GST or GST-HuR (see Materials and Methods). T1, digestions with RNase T1 alone; M, molecular weight

25、 markers. (D) Gel retardation assays using B2 and the indicated concentrations of either GST or GST-HuR. (E) EMSA-Western Assay: Left, cytoplasmic fractions were either incubated with B2 or not, cross-linked, digested with RNase T1, resolved by SDS(15% gel), and transferred onto polyvinylidene diflu

26、oride membranes, which were sequentially exposed to X-ray film for 24 h (Radioactive signal) and subjected to Western blot analysis to detect HuR (Western signal); exposure time, 30 s. Right, Lysates from UVC-treated or untreated cells were incubated with B2 and then subjected to Western blot analys

27、is. Estimated size of the HuR-p21 complexes, 37 to 40 kDa.HuR binds to the 3UTR of p21 mRNArna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控第21頁(yè)HuR表示降低后， p21 3 UTR 與細(xì)胞漿蛋白間形成復(fù)合物（在UVC輻射后）降低， p21 mRNA 穩(wěn)定性降低（半衰期縮短），表示降低。Decreased HuR expression lowers binding to the p21 3 UTR and reduces p21 mRNA stability and p21 induction by UVC. (A) We

28、stern blot analysis of HuR expression in RKO cells, either untransfected (untr.) or transfected with pZeoSV2()HuR, expressing AS HuR. Chosen clonal isolates are shown. Blots were sequentially stripped and rehybridized with an antibody recognizing actin (43 kDa), to visualize differences in loading a

29、nd transfer, and with an antibody recognizing hnRNP C (43 kDa). (B) B5 binding activity in lysates from untransfected and AS HuR-expressing cells 6 h after UVC irradiation. (C) Northern blot analysis of p21 mRNA expression in untransfected and AS HuR-expressing RKO cells 8 h after either no treatmen

30、t () or exposure to the indicated UVC doses. Evenness in loading and transfer among samples was assessed after stripping the membrane and rehybridizing it with an oligomer probe recognizing 18S rRNA. (D) Western blot analysis to assess the expression of p21, c-Jun (39 kDa), and actin in untransfecte

31、d and AS HuR-expressing RKO cells 10 h after either no treatment or exposure to 20 J/m2 UVC. p-jun, phosphorylated Jun. (E) Graphs depict the rate of loss of p21 and -actin mRNAs in cells with different HuR levels after actinomycin D (2 g/ml) addition with or without UVC irradiation. At the times in

32、dicated, total RNA was extracted and p21 and -actin mRNAs were monitored by Northern blotting; signals were quantitated with a PhosphorImager, normalized against 18S (not shown), and plotted on a logarithmic scale. The mRNA half-life in each treatment group is indicated in parentheses. Values repres

33、ent means standard errors of the means of three independent experiments.Ectopic expression of the antisense HuR inhibited the interaction of HuR with p21 mRNA and reduced the levels as well as the half-life of p21 mRNArna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控第22頁(yè)UVC 輻射下，B2 （含HuR結(jié)合位點(diǎn)）賦予P21 mRNA 穩(wěn)定性。用反義方法降低內(nèi)源性HuR 表示后，由B2賦予穩(wěn)定性消失。

34、Effect of the full-length and mutant p21 3 UTR on expression of a luciferase reporter construct. (Top) Expression vectors pGL3, pGL3-FL, and pGL3-B2 (see Materials and Methods) were transiently cotransfected into RKO parental (untransfected Untr.), AS.2, or AS.7 cells along with pSV-gal (used to nor

35、malize for transfection efficiency); cells were irradiated with UVC (20 J/m2) or left untreated, and luciferase and -galactosidase activities were examined 24 h later. (Bottom) Relative fold increase in luciferase activity after UVC exposure, seen with either pGL3-FL or pGL3-B2 compared with that se

36、en with the control vector pGL3. Values represent means standard errors of the means of five independent experiments The B2 fragment confers PGL3-B2 reporter ability to respond to the down-regulation of HuR rna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控第23頁(yè)Western blot analysis of HuR expression and subcellular localization. (A) Si

37、x hours after irradiation with the indicated doses of UVC, whole-cell (20 g), cytoplasmic (40 g), nuclear (10 g), and cytosolic (40 g) lysates were prepared and subjected to Western blot analysis to monitor the expression of HuR, hnRNP C, AUF1, BAF57c (57 kDa), and actin. Cell lysates were collected

38、 at the times indicated after irradiation with UVC (20 J/m2) (B) or 6 h after irradiation with the indicated doses of UVC (C), and Western blot analysis of HuR expression performed on cytoplasmic (40 g) and nuclear (10 g) fractions. (D) Indicated doses of ionomycin (Ion.; micromolar) or lithium acet

39、ate (LiAc; millimolar) were added to cells 1 h before UVC irradiation with 20 J/m2 and Western blot analysis of cytoplasmic HuR. Hybridization using antibodies against actin and BAF57c was carried out to assess uniformity in loading and transfer among cytoplasmic and nuclear samples, respectively.UV

40、C induces the cytoplasmic presence of HuRrna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控第24頁(yè)Subcellular localization of HuR. GFP-HuR was visualized by fluorescence microscopy in transiently transfected RKO cells that were either left untreated or treated with 20 J of UVC/m2 (4 h earlier). DAPI staining served to visualize the nucleu

41、s. Note the distinct overlap of DAPI and GFP-HuR signals in untreated cells; while UVC-irradiated cells also exhibit abundant nuclear GFP-HuR, the treatment causes a substantial increase in the cytoplasmic GFP-HuR signal, not seen in untreated cells.UVC induces cytoplasmic HuRrna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控第25頁(yè)Increa

42、sed cytoplasmic HuR and p21 RNA binding after exposure to stresses. (A) Western blot analysis to monitor HuR expression in cytoplasmic and nuclear fractions after treatment with the indicated agents. Samples were collected 2 h after addition of actinomycin (Act.) D (1 g/ml) or 4 h after exposure to

43、100 M H2O2, MMS (100 g/ml), 48 M PGA2, or UVC (20 J/m2). Hybridizations using antibodies against actin and BAF57c were carried out to assess uniformity in loading and transfer among cytoplasmic and nuclear samples, respectively. (B) B2 binding activity in cytoplasmic lysates of cells treated as for

44、panel and supershift analysis of complexes forming after exposure to such stresses.Induction of cytoplasmic HuR and its binding to p21 mRNA by UVCrna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控第26頁(yè)SummaryUVC在不影響總HuR水平條件下誘導(dǎo)細(xì)胞漿HuR水平UVC誘導(dǎo)HuR與p21 mRNA 結(jié)合HuR 結(jié)合P21 3-UTR后使P21mRNA 穩(wěn)定性增高，進(jìn)而引發(fā)P21表示增高。人為降低HuR水平可降低HuR與P21 3-UTR間相互結(jié)合，降低P21mRNA

45、穩(wěn)定性，降低P21表示，提醒HuR對(duì)UVC誘導(dǎo)P21 mRNA 穩(wěn)定性是必須。rna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控第27頁(yè)Example II AUF1 Regulates Replicative Senescence through Mediating p16 mRNA TurnoverWang, et al; EMBO Rep., 6 : 158-164, . rna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控第28頁(yè)BackgroundCDK inhibitor p16INK4 is induced with replicative senescence. Although transcriptional regulat

46、ion of p16 has been intensively studied, regulation by post-transcriptional mechanism has not been reported.RNA binding protein AUF1 is expressed as a family of four protein isoforms (p37, p40, p42 and p45) arising through alternative splicing. AUF1 binds to AU-rich elements (ARE) or AUUUA motifs in

47、 the 3-UTR of target mRNAs and destabilizes them (different from HuR).Question: Is AUF1 mediated mRNA turnover involved in the regulation of p16 during cellular senescence? rna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控第29頁(yè)P(yáng)16 mRNA 3-UTR contains motifs for biding by RNA binding proteinsrna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控第30頁(yè)SenescenceYoungP16 3-UTR is

48、important for the instability of EGFP-p16 3-UTR (In young cells)Time in Dox (h)Time in Dox (h)rna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控第31頁(yè) AUF1 binds to p16 3-UTR. Binding of AUF1 to p16 3-UTR attenuated with cellular senescence.rna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控第32頁(yè)AUF1 levels reduced with cellular senescence. AUF1 binds to AU rich region of p16

49、 3-UTR.ABCrna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控第33頁(yè)P(yáng)16 3-UTR confers instability to chimeric transcripts in lung carcinoma cells (H2)Time in Dox (h)rna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控第34頁(yè)Knock-down of AUF1 stabilizes EGFP-p16 3-UTR chimeric transcripts in H2 cells rna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控第35頁(yè) Knock-down of AUF1 increases p16 expression and accelerates cel

50、lular senescence of WI-38 cellsrna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控第36頁(yè)SummarymRNA turnover is important for p16 regulation during cell aging.2. AUF1 binds to p16 3-UTR and destabilizes p16 mRNA.3. AUF1 expression reduced with cellular senescence. Reduction of AUF1 during cellular senescence can lead to p16 up-regulation

51、and accelerate cell senescent.rna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控第37頁(yè)RNA-binding protein HuR enhances p53 translation in response to ultraviolet light irradiation.Mazan-Mamczarz K, et al; , PNASExample rna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控第38頁(yè)Backgroundp53是主要抗癌基因， 功效廣泛。 在UVC輻 射下，p53被誘導(dǎo)，但機(jī)制不明。2. UVC誘導(dǎo)細(xì)胞漿HuR。Questions： HuR是否調(diào)控p53? 怎樣調(diào)控? rna結(jié)合蛋白與轉(zhuǎn)錄后調(diào)控第39頁(yè)Fig. 1.UVC induces p53 expression at protein le