Download presentation
Presentation is loading. Please wait.
Published byEverett Cast Modified over 9 years ago
1
The Nobel Prize in chemistry 2004 Ubiquitin(Ub) 泛素 Class B Group 3 黃恒橋、劉國正、黃偲媁 黃竣聖、簡農軒、楊昆霖
2
Nobel Laureate Israel Aaron Ciechanover Israel Avram Hershko USA Irwin Rose http://big5.cctv.com/science/20041008/101027.shtml
3
The Discovery of The Ubiquitin simple protein-degrading enzymes Trypsin Lysosome do not require energy Traditional concept
4
Paradox 1950s - the breakdown of the cell's proteins require energy The inhibitor of lysosome has no effect on some protein degradation Rabbit reticulocytes ( 網織紅血球 ) degrade abnormal hemoglobin
5
The Discovery of The Ubiquitin 1975 - isolated Ub from sweetbread ( 小牛胸腺 ) 1977 - an extract from reticulocytes 1970s ~ 1980s - the extract could be divided into two fractions Fxn1 Fxn2
6
The Discovery of The Ubiquitin ATP-dependent proteolysis factor 1 (APF-1) 1981 ~ 1983 - enzyme systems that binds ubiquitin to target proteins multistep ubiquitin-tagging hypothesis
7
Poly Ub : Ub-proteasome pathway For protein (peptide) recycling Decomposition( proteasome ) The kiss of death Mono Ub: non-degradation Modification(methylation of Histone) The Function of Ubiquitin Target protein Ub Target protein Ub
8
The structure of Ubiquitin A 76 a. a. protein Stable: O H Highly conserved Exist in archeabacteria and all eukaryotes http://www.nottingham.ac.uk/biochemcourses/students/ub/ubindex.html
9
Binding target protein Ub’s C-terminus the target protein’s Lysine Form isopeptide target protein Lysine Ub
10
Poly-ubiquitinization Ub’s C-terminus Ub’s lysine Purpose: recognize diversity protein Protein 1 Protein 2 Ub
11
Target protein L48 vs.L63 Ub L48 L63 Degraded by proteasome Degraded by lysosome
12
Met1-Gln2-Ile3-Phe4-Val5-Lys6-Thr7-Leu8- Thr9-Gly10-Lys11-Thr12-Ile13-Thr14- Leu15-Glu16-Val17-Glu18-Pro19-Ser20- Asp21-Thr22-Ile23-Glu24-Asn25-Val26- Lys27-Ala28-Lys29-Ile30-Gln31-Asp32- Lys33-Glu34-Gly35-Ile36-Pro37-Pro38- Asp39-Gln40-Gln41-Arg42-Leu43-Ile44- Phe45-Ala46-Gly47-Lys48-Gln49-Leu50- Glu51-Asp52-Gly53-Arg54-Thr55-Leu56- Ser57-Asp58-Tyr59-Asn60-Ile61-Gln62- Lys63-Glu64-Ser65-Thr66-Leu67-His68- Leu69-Val70-Leu71-Arg72-Leu73-Arg74- Gly75-Gly76 Other lysine site(human’s Ub )
13
Ub-Proteasome Pathway http://www.bio-pro.de/imperia/md/images/grafiken/ubisystem_338x398.jpg
14
Ubiquitnation Remarkable features The specificity of protein tagging is mainly determined by E2, E3 steps E1:Ub-activating enzyme E2:Ub-conjugating enzyme E3:Ub-ligase E2
15
E1:Ub-activating enzyme E1 AMP Ub S-H ATP Ub adenylate Cysteine Adenylation C-terminus Cysteine Activation
16
E2:Ub-conjugating enzyme E2 AMP Ub adenylate Ub E1 S-HNew E3 1.Connection of polyUb 2.Elongation of Ub with E3
17
E3:Ub-ligase Two types E3s which do form thiol esters with ubiquitin E3s which do not form thiol esters with ubiquitin. E3 From:www.wormbook.org/.../ubiquitinpathways.htmlwww.wormbook.org/.../ubiquitinpathways.html Recognition of the substrate
18
Proteasome Barrel-like structure Degrade ubiquinated protein Use the energy of ATP
19
Structure Core protease particle (CP) Catalytic area Regulatory particle (RP) Ubquitin recognition Deubiquitin ATPase http://www.bioscience.utah.edu/mb/mbFaculty/hill/hill.html α β β α
20
http://www.bio-pro.de/imperia/md/images/grafiken/ubisystem_338x398.jpg
21
Ubiquitin and p53 Tumor suppressor gene DNA repair Apoptosis
23
Cancer reason : HPV Human Papillomavirus Activate E6-AP(E3) to ubiquitinate p53 Few P53 Dysplasia
24
Medicine LDP-341 ( PS-341) Proscript invented in 1995 Inhibit ubiquitin function Retain cyclin Inhibit NF-kappa B Protein pressure
25
Retain cyclin S G1 G2 cdk cyclin M BACK
26
Inhibit NF-kappa B Promote cancer cells and vessels Restrain apoptosis inhibitor I kappa-B DNA I kappa B NF-kappa B BACK
27
Protein pressure Too much protein in cell Short time pressure Take in interval Disadvantage and improvement Non-selective E3 influence BACK
28
Spinocerebellar Atrophy ( 小腦萎縮症 ) Background detail Cause of disease- gene Symptom nervous system: cell death Behavior: paralysis One of causes- ” inclusion bodies “( 包涵體 ) Proteins are combined by SUMO-1 SUMO(Small ubiquitin-like modifier)
29
SUMO( 類泛素 ) Small ubiquitin-like modifier Function: Modification Proteins linked by Ub or SUMO could be recognized by cell and be sent to different organelles. Threat
30
Abnormal SUMO In Spinocerebellar Atrophy Abnormal protein SUMO Ub Abnormal protein SUMO Abnormal protein SUMO Abnormal protein SUMO Abnormal protein SUMO Finally cell death
31
Parkinson’s Disease ( 帕金森氏症 ) Background detail Cause of disease- gene Symptom Nervous system: death of basal ganglia ( 基底核 )and substantia nigra ( 黑質 ) cell Behavior: tremor ; rigidity Dopamine( 多巴胺 ) Reason (related to ubiquitin) Abnormal α-synuclein gene Abnormal parkin(E3) gene
32
Abnormal α-synuclein protein Ub Abnormal α-synuclein gene Abnormal parkin(E3) gene Finally cell death Abnormal parkin(E3) Abnormal protein Abnormal α-synuclein protein Ub Abnormal α-synuclein protein Ub Abnormal α-synuclein protein Ub E2 Ub
33
Take Home Messages Ub target substrates for degradation, traffic, or modification. The well-known function is involving ubiquitin proteasome system(UPS). Ubiquitination has to be aided by E1:activating Ub E2:regulating poly-ubiquitinization E3:recognition of substrates
34
Take Home Messages Mechanism of P53,HPV, Spinocerebellar Atrophy and Parkinson’s Disease are all related to the ubquitination, especially the function of E3.
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.