Cell Death And Apoptosis Flashcards
Morphological markers of apoptosis:
- _____-dense nucleus
- _____ fragmentation
- _____ cell membranes
- ______ cytoplasmic organelles
- _____, ____ vaculoles
- _____ at the surface
- loss of _____ _____
- _____ bodies, which are chunks of _____ and _____ that are ___-dense
- cell shrinkage
Morphological markers of apoptosis:
- ELECTRON-dense nucleus
- NUCLEAR fragmentation
- INTACT cell membranes
- DISORGANIZED cytoplasmic organelles
- LARGE, CLEAR vaculoles
- BLEBS at the surface
- loss of CELL-CELL ADHESION
- APOPTOTIC bodies, which are chunks of CHROMATIN and ORGANELLES that are ELECTRON-dense
- cell shrinkage
Biochemical marker of apoptosis:
- ____ flipping into the _____ leaf of membrane bilayer
- ____ gets upregulated
- DNA _____, which happened when acted upon by _____
- _____ cleaves _____ at _______ regions, resulting in fragments of ____-____ bp long.
Biochemical marker of apoptosis:
- PS flipping into the EXTERNAL leaf of membrane bilayer
- FLIPPASE gets upregulated
- DNA LADDERING, which happened when acted upon by CASPASE-ACTIVATED DNASE (CAD)
- CAD cleaves DNA at INTERNUCLEOSOMAL LINKER regions, resulting in fragments of 180-185 bp long.
TUNEL Assay
-labels ____ end of DNA fragments
TUNEL Assay
-labels 3’ end of DNA fragments
Intrinsic Pathway:
- receptor- ________
- signal is usually _______, which triggers ____
- ____ activates the intrinsic pathway through transcriptional upregulation of pro-apoptotic members of ____ family such as ___ and ____.
- ______ and _____ tie up anti-apoptotic _____ and _____, allowing ____ and ____ to aggregate and form ____ in the mitochondrial membrane, and allow release of cytochrome C.
- Cytochrome c from the mitochondrial ______ will bind ____ and cause displacement of ____ ____ ____, which causes conformational change, so it can assemble with ___ ______, forming the _____.
- The _____ binds _____, and self-catalyzes, becoming active, then cleaves ____, which will assemble into active ____, forming a positive feedback loop.
- Active ____ will cleave executioner caspases ,,_, which are responsible for ____,____,____
- ______ / will cleave _____ which will oligomerize to become active ____.
Intrinsic Pathway:
- receptor-INDEPENDENT
- signal is usually DNA DAMAGE, which triggers P53
- P53 activates the intrinsic pathway through transcriptional upregulation of pro-apoptotic members of BCL2 family such as PUMA and NOXA.
- PUMA and NOXA tie up anti-apoptotic BCL2 and BCL-XI, allowing BAX and BAC to aggregate and form PORE in the mitochondrial membrane, and allow release of cytochrome C.
- Cytochrome c from the mitochondrial INTERMEMBRANE SPACE will bind APAF1 and cause displacement of CASPASE RECRUITMENT DOMAIN, which causes conformational change, so it can assemble with 6 OTHER APAF1, forming the APOPTOSOME.
- The APOPTOSOME binds PROCASPASE-9, and self-catalyzes, becoming active, then cleaves PROCASPASE-9, which will assemble into active CASPASE-9, forming a positive feedback loop.
- Active CASPASE-9 will cleave executioner caspases 3,6,7 which are responsible for DNA CLEAVAGE, PS FLIPPING, AND MORPHOLOGICAL EFFECTS
- CASPASES 3/7 will cleave ICAD AND CPAN which will oligomerize to become active DNASES.
BCL-2 Superfamily Consists Of:
- Proapoptotic members such as ____, ___, and ___
- Multidomain members such as ___ and ____
- Anti-apoptotic members such as ____ and ____
BCL-2 Superfamily Consists Of:
- Proapoptotic members such as NOXA, PUMA and BID
- Multidomain members such as BAX and BAK
- Anti-apoptotic members such as BCL-2 and BCL-XL
Multidomain BH 1,2,3 Proteins:
- ___ localizes to outer membrane of mitochondria
- ___ is localized in cytoplasm
Multidomain BH 1,2,3 Proteins:
- BAK localizes to outer membrane of mitochondria
- BAX is localized in cytoplasm
What do Bcl-2 and BCL-XL Do?
-Bind to ____ and ____ to prevent their aggregation, _____, and release of ____.
What do Bcl-2 and BCL-XL Do?
-Bind to BAX and BAK to prevent their aggregation, PORE FORMATION, and release of CYT C.
Apoptosis and Cancer: Bcl2
-In follicular lymphoma, ________ commonly occurs between chromosome 14 and 18 which places Bcl-2 gene next to ______’s locus enhancer. This leads to high levels of Bcl-2 expression and decreased propensity of cells to ______.
Apoptosis and Cancer: Bcl2
-In follicular lymphoma, CHROMOSOMAL TRANSLOCATION commonly occurs between chromosome 14 and 18 which places Bcl-2 gene next to IgG’s locus enhancer. This leads to high levels of Bcl-2 expression and decreased propensity of cells to UNDERGO APOPTOSIS.
BH3-Only Proteins:
- ____, ____, and _____
- they bind _____, preventing it’s association with ___ and ____.
- ____ and ____ will be free to do what they do.
BH3-Only Proteins:
- PUMA, NOXA, and BID
- they bind BCL-2, preventing it’s association with BAK and BAX.
- BAK and BAX will be free to do what they do.
p53’s Many Mechanisms of Anticancer Function
- it can activate ____ ____ proteins
- it can _____ cell growth
- it can initiate _____
p53’s Many Mechanisms of Anticancer Function
- it can activate DNA REPAIR proteins
- it can ARREST cell growth
- it can initiate APOPTOSIS
p53 Activity in Unstressed Cells
- It’s levels are kept ____ via _____
- ____ acts as a _____ and attaches ______ for _____
- ____ also transports ____ from nucleus to cytosol
p53 Activity in Unstressed Cells
- It’s levels are kept LOW via CONTINUOUS DEGRADATION
- MDM2 acts as a UB-LIGASE and attaches UB for PROTEASOME DEGRADATION
- MDM2 also transports P53 from nucleus to cytosol
How is p53 activated for DNA Repair?
- DNA Damage activates ___/___ which are _____.
- ____/_____ activates _____/____ which phosphorylate p53.
- once active, p53 no longer binds ____ and is no longer ____
- p53 forms ____ and gets transported to ____, where it acts as a ___
How is p53 activated for DNA Repair?
- DNA Damage activates ATM/ATR which are SER/THR KINASES.
- ATM/ATR activates CHK1/CHK2 which phosphorylate p53.
- once active, p53 no longer binds MDM2 and is no longer UB-LATED
- p53 forms TETRAMER and gets transported to NUCLEUS, where it acts as a TF
Extrinsic Apoptosis Pathway
- receptor ____ [____ and _____ with ligands ___ and ____]
- independent of ____
- form _____ components that get together to ultimately activate _____ (initiator for extrinsic pathway), which will eventually activate ____.
-_____ binds _____, which causes conformational change in _____, which recruits ____, which creates _____, which then recruits ______ via _____. This activates ____, which will cleave ____.
Extrinsic Apoptosis Pathway
- receptor DEPENDENT [DR4 and DR5 with ligands APO2L and TRAIL]
- independent of P53
- form INTRACYTOPLASMIC components that ultimately activate CASPASE 8 (initiator for extrinsic pathway), which will eventually activate CASPASES 3,6,7.
-LIGAND binds RECEPTOR, which causes conformational change in CYTOPLASMIC TAIL, which recruits FADD, which creates DEATH INDUCING SIGNALING COMPLEX (DISC), which then recruits CASPASES 8,10 via FADD. This activates INITIATOR CASPASES, which will cleave DOWNSTREAM CASPASES.
Extrinsic and Intrinsic Pathways Converge via ___ and _______
Extrinsic and Intrinsic Pathways Converge via BID and CASPASES 3,6,7
