腫瘤分子生物學(xué)-3.ppt

1、1,2,1. 現(xiàn)有“生物信息學(xué)”的限制： “有眼不識泰山” 第一外顯子 識別能力 外顯子內(nèi)含子 識別能力 2. 一個基因：不同剪切體 Splicing form (Isoform) 3. 一個基因 蛋白質(zhì) 切割： 蛋白質(zhì) 1 肽段,人基因組計劃已經(jīng)給了我們多少？,人基因有多少個？,10萬 3萬？,3,4. 同一個蛋白質(zhì) 細(xì)胞內(nèi)的不同 “定位” 不同功能！ 5. 98 DNA序列：功能不明 ! （95）,細(xì)胞核,細(xì)胞質(zhì),線粒體,細(xì)胞膜,蛋白質(zhì)移位 Translocation,4,E1 b E1 a Exon 2 Exon 3,p16 Ink 4a,P14 ARF (human) P19 ARF

2、(mouse),Cross Talk betweren Oncogenes PKC 4E-BP dissociation & release of elf-4E cap dependent initiation translation of 5-UTR,37,P1 (3) K dependent cyelin D3 Phosphorylation of Rb and p107 E2F Involved in P1 (3) K and Akt tumorigenesis Dependent on Phosphorylation & activation of p70S6K,Ribosomal S

3、6 Kinase S6K1, S6K2,Regulator of cell growth & protein translation p70S6K short isoform of S6K 1 Cytoplasic in large part Activation is blocked by rapamycin Mediate mTOR effect on protein-translation Phosphorylation of S6 subunit (40s rs protein) S6 translation of 5 ter. Pyr-rich tract (5-TOP mRNA),

4、Also involved in cell cycle,38,Wnt Pathway,Wnt Wnt 1 = ( int-1, mouse MMTV integration activated gene) Porcupine: A gene for wnt secretion Polytopic membrane protein Related to acyl transferase Frizzled ( Fz ) Wnt Receptor Dally: Co-receptor of Wnt Glypican-type heparan sulfate proteoglycan Glycosyl

5、-Ptd Ins moiety membrane b-catenin: in absence of Wnt Destabilized by a protein complex Dishevelled (Dsh) activated by Wnt-Fz binding Axin APC GSK-3b (Glycogen synthase kinase) GSK - 3b - b-catenin - b catenin degradation Wnt Fz binding Dsh GSK - 3b b-catenin stabilized enter nucleus Nuclear transcr

6、iption factor: Tcf / LEF: activated by b-catenin,39,Wnt Pathway,TCF / LEF,APC,GSK 3b,TCF / LEF,b-catenin,LRP,Fz,40,Hedgehog Pothway,Hedgehog: Embryonic development inducer Hh, hh: Humna Shh (Sonic hh) Ihh (Indian hh) Dhh (Desert hh) 19KD protein C Cholesterol ester N Palmitoylation (after cholestero

7、l addition, enhancing signaling) Secretion of hh: 2 genes: Dispatched related to hh R Patched hh release Toutvelu: enzyme, heparin-SO4 synthesis for transport and response of hh Receceptor of hh Patched (Ptc): Ts, 12 Span-transmembrane Proton-driven lipid transportor Smoothened (Smo): Onc, 7-transme

8、mbrane p ( Fz like ),41,1. hh (-): ( in a complex) hh (+): 2. Smo activated: coupled with a complex 3. hh (-): (1) Ci N ter. transcription repressor (Ci 75) (2) Ci in cytoplasm ( Cos2 / Fu / Su / Ci complex anchored on microtubule) 4. hh (+): Costa / Fu / Su / Ci dissociated from microtubule Ci (Ful

9、l length): enters nucleus Transcription of genes ( ptc, Hip and growth genes),Activation of hh Pathway,hh Ptc Smo*,hh - Ptc,Smo*,Smo*,Fu: Fused, S / T PK Su: Suppressor of Fu Costa 2 ( Cos. 2 ) : Kinase like Ci: Cubitus interuptus, ZF TA Gli in mammal,PKA,42,Su,Fused (Fu),Costa 2,Smoothened (Smo),Patched (Prc)