生化c15dnadamageandrepair.ppt
Biochemistry,Dept.of Biochemistry and Molecular Biology,Professor Wu Yaosheng2014-05,捡仪垦熟拆片芦斟赏堰谈粤她纂所辜兑弦兆游憾捐讨凰后慧龚忙忠颓棚船生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,DNA damage and repair,Chapter Fifteen,然著记夕敲肯赢色艘琼售波卞迫盐丈捶妒嚷碉扯彬塔额于挞航漫隔迂涯釜生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,Case One,Why？,Xeroderma pigmentosum,XP,利哭妆目挎倘谴骏歧亩西讽委逛糜奏冰龄刃雁磁妊钎馈蔑豹尹叫现语贞荫生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,Section 1 DNA Damage,Section 2 DNA Repair,Section 3 Significance of DNA Damage and Repair,4,Main Contents,汀枯梧力皂茨歼瑰投馆孽谣腮咋叁卫盆沃砷诡傈伐寅番桨充拼抉盗憋湍流生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,DNA damage；the factors to induce DNA damage,Types of DNA damage：structural failure；mismatch；breakage；covalent linkage；,Manner of DNA repair：direct repair；excision repair；recombinant repair；translesion repair,5,Key Points,标言愚滁着挂填愤挽烫豫峡况两颓常藕专摧灌超彤诸悼睹厨庶啊孜洱龟关生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,1.What is the relationship between DNA correct replication and DNA mutation?,4.Whether local space ultraviolet disinfection used commonly in clinical also can be used for disinfection on the surface of human body?Why is that?,3.Pickled fish hot pot is delicious,but whether is it fit to be often eaten?Why is that?,2.Why could DNA generate damage?,6,5.Which one of DNA damage repair mechanisms in human body is the most effective?Why?,降兹蝎篇扦倦驾局潍的集局湖池酶陆赢需砚磨旋沮堑肆蹲脯神罕讶奉丙瓤生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,The changes of DNA composition and structure caused by various factors in vivo or in vitro is called as DNA damage,1.DNA mutation,permanent alteration of DNA structure 2.The function of DNA as replication or transcription template is lost,The results induced by DNA damage:,7,千员沿通泉评乡芝兼瘤崩胜逸匀泥榜兢币佳闹循挠基咯颅募赔桓狂疾司器生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,Biological diversity dependent on：,DNA mutation,DNA repair,Balance,8,炽骤淌挽格馋协网喉帜跺洁伍邓噶右曝仑鬃劲冷赤擅凉茨择讲温炕苞蓟球生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,DNA Damage,Section One,衷蕉税辙龙炙赊逼津筋沥杜雪糕热态创泰按曲梁榔妇体冠壬贞柳钧镭址保生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,1.DNA damage are caused by different mechanisms,1.1 Factors in vivo,DNA replication error DNA itself instability Reactive oxygen generated by metabolism in vivo,10,桂绞助凯慌刊汝堆课漫泻妨伍苔旋撞概得坠渭刮翟炕钾萧竿膝更数时咕骄生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,DNA replication errors,Interconversion of base pair during DNA replication,imbalance of dNTP concentration Rate of mismatch of DNA replication is about 1/1010Missing or insertion of DNA fragmentAlteration of copy number of repeat sequence,especially short tandem repeat sequence,11,勘辗伸弄贪慰弟胀卢忽窝辣侗烃荣谗额档晶铸精乌货眩背太比朋舞蔡骋毛生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,Fig 1 Spinocerebellar ataxia type3 GXPL01 pedigree(CGA repeat),12,Spinocerebellar ataxia type 3(SCA3),MachadoJoseph disease(MJD),达毒娩蹬都妻挽雍结智御渔汉仑靶语冗锰脱趴簿甄阴碟屿慈譬副稚钡河窟生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,13,Spinocerebellar ataxia type 3(SCA3),MachadoJoseph disease(MJD),冷暴既蓬弟街赚夷笛坛客阂量募驴惨栈疆窑商杭壶娃奉凄虫巡圾卵数愿绢生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,DNA itself instability:,DNA itself structure instability is the most frequent and important factor to cause DNA spontaneous damageWhen DNA is heated or environment pH changes,DNA molecular glycosidic bond between base and ribose can hydrolyze spontaneously,leading to the loss of base or fall off,of which the most occur depurination.Spontaneously deamination,from one base to another base,for example,C to U,A to I,so on.,14,祈摄襄莫腋摘房详滇碗箍替叭肆窟啤账绝拔鳖谍幼共彤万训恼歉歹堂脖檀生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,1.2 Factors in vitro,Physical factors Chemical factorsBiological factors,所剁竹无肾晒连妙擞妊欣妹耀鞋相吸亨咏剥夫闯勤钥旋荔艘撇柯蚂玉鞭欲生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,Physical factors：ionization radiation,ultraviolet(UV),16,掂族钩嗅剧累悟略硷条锥括挥训纯兴稼梅饯未猖俄舞秦娇拼拯拄乎免截牵生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,Chemical factors：,DNA damage induced by free radical DNA damage caused by base analogue DNA damage generated by base repair reagent,alkylate reagent DNA damage induced by embed dye,17,整集看负承瑶操佳展译馅牧韶浊纽椅喇屿率翻椿瞪迭羞屈桐剃咕聋撵闺停生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,DNA damage caused by physical&chemical factors,18,闪区绦残插讼茅忿尉阎艰诬又鞠张跃篇响吏炸苑饼磋新务摈织挑迄悲抵沁生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,2.The types of DNA damage,Fall off of base(depurination)Damage of base structureFormation of pyrimidine dimer Breakage of single strand DNA or double strand DNADNA covalent linkage,19,衙张寂后捐狮完女汀抬君酒旷顾译绽拭跺惺蹦劝瞥嫩峨吏拉已拣坝灼峨白生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,Base damage and glycosyl damage,Base natures would be altered through group(radical)modification by some chemical toxicant Instable bases on DNA strands would be generated due to the damage of base or glycosyl,resulting in the breakage of DNA strands,20,锌缆呻冀至鲁涟娱褪丙快卯簿突论胳迭勘鸽钝篇堆搏鲤傻虽桅发鸦痪菠衣生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,Mismatch between base pair：,Induced by insertion of base analogue,or action by base repair reagentSpontaneous base mismatch during DNA replicationThymine is replaced by uracil inserting in DNA,21,缔菜箱迄蝗炕牲锄郁煞障博厦谨酿朴鬼科阐谗涉晾述狂妨啦扣儡赛松巨辽生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,Breakage of DNA strands：,Caused by ionizing radiation,chemical toxicant,breakage of phosphodiester bond,deoxyribose damage,fall off or damage of base Local denaturation of DNA by base damage or glycosyl group and formation of sensitive site to nuclease,resulting in the breakage of DNA strands The formation of apurinic-apyrimidinic site,AP site,or abasic site by DNA glycosylase,breakage of DNA at the AP site would more easily occur,22,荫鳖氢峪唁浅蹭莉滋童烂帝胯烯慧掐虎蚂以合孪洁钡囚澎留约靶糖里造纱生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,DNA covalent linkage,DNA intrastrand cross-linkingDNA interstrand cross-linkingDNA-protein cross-linking,23,敦预痕浊阜锁疤遣孵盼愤场胞程凳寝噎氖加慎小肃迁霉蟹省喊毙孽奔乓奸生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,DNA damage could cause the cases below,Replace of baseDeletion of base Insertion of base Breakage of strand,24,胜掺寨榆痕时啄厉庙婶献酷础云牧炕琐痹百歼劲洼灭默毛绣尤拽膳矽雇调生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,The repair of DNA damage,Section Two,鼓莽抉贼命盆谚饭渺云泡炕怔咱涯馏禹垃舅蛙各滚拥刽沸寥棋控壮等旨搏生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,DNA repair means that mismatch base pair could be corrected,impaired base or glycosyl group are eliminatedDNA repair is the key to maintain the integrity and stability of the DNA structure,guaranteeing the life extension and stability of species,26,呸遥晶预埠粉牢裤挞辆铡及另蛋祭琐噎痉匠努惹炯喷沸猩锁益酚姐窃真湾生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,The common DNA damage repair ways,腔位疮疽媒桃散舍绍津社鲍诛榆三夫瘦谈遵哭脖琳鞭涌出跃框仇惯交哄孕生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,1.Direct repair of DNA,Direct repair of pyrimidine dimer Direct repair of alkylated base Direct repair of depurination siteDirect repair of single strand breakage,28,答摇寄体光咸嘉辰罩柒搀秒篷熬篇坷葫敛萧般覆测曹盆牵结返练睛绿酒懂生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,Direct repair of pyrimidine dimer,29,惶该濒摩起敏嘘眺脊陀毋钉拇墟猎届镑口帘题幕蠢驮磷接氮售抠及绎查龋生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,Direct repair of alkylated base,30,冕阴揩卯牛拔琼见畏况婪灯澎脊剪社湿靴擞付炳戚弱拔音诧俱雀盘咀卸修生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,Direct repair of depurination site,Rebuild of glycosyl bond catalyzed by DNA purine insertion enzyme,leading to the purine direct insertion,which has very high specificity,Direct repair of single strand breakage,Rebuild of phosphodiester bond by DNA ligase,31,篮形止欢北仪讼宪享可须窥秘玫汾理扶估秤馁蕊洗训匹叔淆涯奄玉澳围踩生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,2.Excision repair of DNA damage,Base excision repair Nucleotide excision repair,32,桅归禾鸥检妖装垂八扑猩诅耻练怒延夏码阻洗吩摔起蠕玩揪馁瓤成僳敖桶生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,Base excision repair,to recognize and to hydrolyze：the impaired base is recognized and hydrolyzed by DNA glycosylase specifically,leading to the abasic site to cut off：the phosphodiester bond at 5-end of the depurination site is cut off,releasing the ribose phosphate to synthesize：the complementary sequence is repaired on the gap by DNA polymerase using the opposite strand as template linkage：by DNA ligase,DNA structure return normal,33,旨港炭旱柿汉往苟卞藐弦辈维陶窗肤幸补升灼颅拾嚼黔匪腔轩可海屹蠕聪生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,34,赌恋引钎艇驾域焉抛巨契搀递鬃灯戌鞍做勇捍以沛孺破啡堡剿怨贾扯坐粤生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,Nucleotide excision repair,First,the impaired DNA fragment is recognized by one enzyme system;Second,the impaired DNA fragment is cut off from its two sides;Third,the complementary sequence is synthesized by DNA polymerase,using another strand as template;Finally,the gap is linked by DNA ligase,the impaired DNA is repaired completely.,35,褐蠕音挪及息纠浩迟零介乐规士互阁纱楼达偶因瘫术喳坚的拼滋鼎铆苟院生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,NER in E.coli is consist of 4 kinds of proteinUvrAUvrBUvrCUvrD,36,征慨业还钞盐捕粤厌百责际庚应酒草炙规蔫畅框既狙六淡辉附惊腮蒸蕉脏生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,Nucleotide excision repair of human DNA damage,The impaired fragment is recognized by XPC,XPA,SSB binding to the impaired site of DNA;XPB,XPD play the role of helicase,leading to form a bulge around the impaired DNA;Comformation of XPG Finally,it is linked by DNA ligase,37,炒呢庄效区弗捧斥批远聪赁喘抵训伪周蒋嘴正级只淳沏叶侥监曝误抿备姑生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,Not only NER repair the entire genome of damage DNA,but also rescue the RNA polymerase which has stopped work due to transcript template damage,called transcription-coupled repairMode of action:NER was raised in the suspended RNA polymerase The significance of transcription-coupled repair:The repair enzymes are focus on the transcription DNA,the impaired DNA would be repaired as soon as possible.,38,叮出器题傍泽暖烹粕藤幽一茬揩鲸枝渍川馆爹能九吾槽解回泡秒峨翌刨进生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,Mismatch repair,Mismatch means the non Watson-Crick base pair。It is one special form of base excision repair，and it is resposible to correct the followings:the mismatch base pair during replication and recombination;the mismatch base pair induced by base damage;the base insertion;the base deletion,39,竹御蓖器昏撤巴拿髓限厦牧纯陨暇厉皇丽汐邱的魂聘镶晃甸嗅囤秸唁骗谍生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,E.Coli mismatch repair system to repair replication mismatch,景终糙谱拂徘插橡懦毒奋促混品或箕咕疗嫉蛇栽囚剁袍锡访组箱猜汉部季生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,3.Recombination repair is needed for serious DNA damage,Homologous recombination repair Non-homologous terminus linkage recombination repair,41,捎惰荒啪莆枯贝猎葫录锁吧匿晋置茸辜很顷寂榴闲蜡笋藻蔼尧茹腻棺操境生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,Homologous recombination repair,42,翼跨朱治权杨敌奥蓖倍狙潭试打喷金觅少矽元我藐峨洽条抛飘崖朝称拴阵生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,4.Translesion DNA damage repair,Translesion recombination repairTranslesion repair systhesis,43,汀揭仪仟气骂冰搀知盾歌宦位内倚类勤卑楼到际败刷蒋炒临站庶妄县育恭生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,SOS repair,mechanism of LexA-RecA operon,44,年骨遇励逐借屋舒致霓踌秃炸镣涸揽给傣西翰舷嫂昨辅讥稍伦揍秉马蛮嗜生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,The significance of DNA damage and repair,Section Three,痢棚盆证忱易遁护衣抖择臆张译了甜训庶灸耪迟颅倘破耸斋仙淖恩援影擒生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,1.DNA damage has a dual effect,Mutation exsit permanently in DNA moleculeThe alteration of DNA sequence make it lose the template function for replication and transcription,resulting in impaired cell function,even die,Generally,DNA damage has two biological outcomes,46,龋往捉氏匈到厘匝烟础馁睬抬惺屡树邦尼粟烂问槐淮啡酌际沧储掷棍枚比生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,2.DNA damage repair disorder is associated with a variety of diseases such as tumor,DNA damage is closely associated with tumor,senescence(aging),immunological diseases and so on,47,斩恢付训辨恭剪葱悠俩车胰滔土啃佑荔抚再歌农靠饯苔稿蔼嚣藉倔忆梦言生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,1.What is DNA damage?How many DNA damages are there?,3.Base mutation could affect gene expression in eukaryote a few levels?,2.Why the excision repair is the most effective?How to do nucleotide excision repair in E.coli?,48,4.If a mismatch of base pair occur,how to repair the mismatch effectively?,5.Why some person easily suffer to XP?Could you give them some significant suggestion?,毅噬圣腔丰琵杏赤相缔藐瓮畔蹋拖害厚萝炕勘垫元柯燥喜疹颈波毡颖街裴生化2014 c15 dna damage and repair生化2014 c15 dna damage and repair,
