细胞凋亡线粒体途径的调控(精)

+IL-2 Bad
Activated kinases Akt, Psk, PKA etc.
Bad phosphorylation
- IL-2
PP1a
Ras
Akadaic acid (冈田酸)
apoptosis
Bad dephosphorylation
?
How these phosphatases are regulated in vivo by apoptotic signals remains to be invested?
Regulation of mitochondrial apoptotic signals
Tanslocation of the BH3-only family of proteins to mitochondrail Cleavage of Bid Phosphorylation of Bad Disassaciation of Bim Transcriptional regulation of BH3-only proteins Tanslocation of other proteins to mitochondra during apoptosis
Receptors
Death-signaling pathway
DISC
(死亡诱导信号复合体)
Cleavage of Bid
Type I cell
Type II cell
mit mit （肝细胞）
Bcl-2
enough
Cas-8
Not enough
cleave
apoptosis
Bid
tBid
mit
?
Abundance of Bim
Be regulated at the level of transcription
Transcriptional regulation of BH3-only proteins
Apoptosis requires new proteins synthesis transcriptional regulation of BH3-only protein may be important for apoptosis newly generated protein
纳巴霉素
Ser112
The critical site of phosphrylation By survival factors
p70S6 kinase
Ser155 Ser136
Bcl-xl
BH3 domain of Bad
Ser155 kinases
14-3-3
Ser112 136
155
apoptosis
BH3 domain
Noxa, Puma
(BH3-only member)
Noxa, a BH3-Only Member of the Bcl-2 Family and Candidate Mediator of p53Induced Apoptosis
2000, science 288:1053
rease
apoptosis
Phosphorylation of Bad
Bcl-2(active)
(In mit)
inactive Bad (In
cytosol)
- Survival signals
apoptosis + trophic factors
Akt, PKA
(In cytosol)
14-3-3 pro
Release of endonuclease G
EndoG release Bcl-2 family
DNA fragment
apoptosis
Independent of caspase activation
Features of mitochondriainitiated apoptosis
Release of apoptosis-inducing factor Release of endonuclease G
Release of cytochrome c
Cyto c Apaf--1
+dATP /ATP
Cas-9
Chr 浓缩
DNA分解
核膜裂解等
Cleave intracelluar substrates
C-Jun
Transcriptional regulation of BH3-only protein play a major role in DNA damage apoptosis
X-irradiation
DNA damage
P53
Cytochrome c release
trigger
Caspases activation
Directly target
mit
Neuron and hematopoietic progenitors(造血干细胞)
④
HRK transcription
- Cytokine
AKT
①
apoptosis
FKHR-L1(叉 头转录因子)
②
-NGF （In neurons) ③ 显性失活的
Bim transcription
Electrostatic（静电） and 空间限制
Phosphatases (In vitro)
Bad-p
dephosphorulated Bad
Calcineurin(钙调磷酸酶) Protein phosphatase 1a Protein phosphatase 2A
Protein phosphatase 1a is a Ras-activated Bad phosphatase that regulates interleukin2 deprivation-induced apoptosis
Even when caspase-dependent and caspase-independent pathway cannot function properly, mitochondrial dysfunction may lead to cell death.
The best way to prevent cell death is to block apoptotic signals before mitochondrial damage occurs.
EMBO J. 19:2237-2246
Materials: interleukin-2 (IL-2)-dependent murine T-cell line Methods:Using the yeast two-hybrid system, glutathione S-transferase (GST) fusion proteins and co-immunoprecipitation techniques, Results: Bad interacts with protein phosphatase 1a (PP1 a ).
Amlified signals
translocation
Fas/FasL
Bid (cytocolic
In living cells )
signals
tBid
tBid
(mit)
Cyto C realease
Cas-8 cleave (cyto)
Domain: helicese 4-6 Specificity: mit-specific lipid, casdiolipin(心磷脂) Efficiency: enhanced by myristorylation (豆蔻酰化) of Nterminal glycine residue of tBid exposed after cas-8 cleavage
apoptosis
Other regulation pathway
Other cas (cas-3) cas-8 Bid (cyto) other BH3-only proteins
And protases
(粒酶 B, 溶原体蛋白酶 )
(inactive Bad) tBid active Bad tBid (mit)
Three general mechanisms
1. Disruption of electron transport and energy metabolism. 2. Release of caspase-activating proteins. 3. Alteration of cellular reduction-oxidation potential
Tanslocation of the BH3-only family
of proteins to mitochondrail
BH3-only proteins (Bid, Bad, Bim, Noxa, Puma)
Other cellular compartments
mit
Bcl-2 familly Cause mit damage Release cyto c, Smac, AIF,EndoG etc.
Interaction of Bad and PP1 phosphatase.
Interaction of Bad and the catalytic subunit of PP1 phosphatase in the two-hybrid system.
Disassaciation of Bim
Regulation of mittochondrபைடு நூலகம்al
apoptotic pathways
Regulation
of mitochondrial apoptotic signals.
Mitchondrial response to apoptotic signals.
Loss of mitchondrial functions during apoptosis.
Multiple factors function to trigger cell death in conjunction and in parallel ways.
Features of mitochondriainitiated apoptosis
the pathway is able to feed-forward and amplified the apoptotic signal.
Cas-3
Release of Smac
Release of apoptosis-inducing
Factor(AIF)
57KD黄素蛋白 AIF (Mit) Nucleus
Chr 浓缩
DNA 降解
Independent of caspase activation and oxidoreductases activity of AIF
Cleavage of Bid
Cell surface death receptors Fas/CD95
extra
TNFR1
DR-3,4 TRAIL-R1,DR5 TRAIL-R2
FasL
TNF Apo3L
Cys-rich
Apo2L/TRAIL ligand
Death domain tail cytoplasmic
cytosol
Microtubule complexes
LC8
Bim
mit
Bim-deficient lymphocytes are resistant to certain apoptotic stimuli.
Cytokine deprivation（细胞因子缺失） Calcium ion flux（钙离子流出） Microtubule pertubation(微管干扰)
Tanslocation of other proteins to
mitochondra during apoptosis
P53
TR3
P53AIP
?
?
mit
?
LKB1
apoptosis
?
Cyto c etc.
Mit damage
. Targeting p53 to
mitochondria of p53deficient cells is sufficient to induce apoptosis.
细胞凋亡线粒体途径的调控
Regulation of mittochondrial apoptotic pathways
高方远 马欣荣 康海岐
Execution of mitochondrial apoptosis signals
Release of cytochrome c
Release of Smac