9 Flashcards
what is Ror ?
RTK-like Orphan Receptor
(found in the Wnt-Ca2+ pathway)
—— can trigger mitochondria to release Cytochome C
Ca2+
What does Cytochrome C in cytosol do?
mediates the assembly of apoptosomes
what is Autophagy?
During periods of stress or starvation it is a process causing cells to break down and destroy damaged or abnormal proteins/organelles, and then recycling them.
what is Rapamycin?
-immunosuppressant
-bacterial antifungal agent
-INHIBITS primarily mTOR (1) Complex
Rapamycin = Sirolimus
what is Hamartin and Tuberin ?
Hamartin and Tuberin are proteins that form a complex known as the TSC1/TSC2 complex (Tuberous Sclerosis Complex 1 and 2).
This complex regulates cell growth and proliferation by inhibiting the mTOR pathway.
- tumor suppressor genes!
Autophagy can be overridden by —-?
AKT
Macroautophagy
Macroautophagy is a specific type of autophagy involving the formation of autophagosomes that becomes engulfed by a lysosome = autolysosome
** formation of phagophore then autophagosome then lysosomal fusion
Steps in Macroautophagy
1) Phagophore nucleation
2) Growth and Elongation
- recruitment of new membrane and Atg proteins
3) Targeting and fusion
- Atg8 is proteolytically released before fusing (saved for next time)
- release allows fusion proteins to bind lysosome (the degradation begins)
Atg is aka?
LC3-I
how does a LC3-II vesicle form?
Atg8 (LC3-I) is linked to Phosphatidyl Ethanolamine (PE) to form LC3-II vesicle
Atgs and forming a double membrane
- Atg12 (Ub-like) links to Atg5
- Atg12-Atg5 can then associate with Atg16
- Atg12, 5,16 Ligates with Atg8 (LC3-I) = LC3-II when Atg8 binds PE
- the complex or autophagosome is a double membrane
what does ACL stand for? and what pathways use these steps?
activation
conjugation
ligation
Both the Ubiquitin-Proteosome system and Autophagy use the ACL steps
Steps in the Wnt/Ca2+ pathway?
Wnt Ligand bind to the Frizzled receptor on the cell surface.
The receptor activates Dishevelled, which triggers downstream signaling.
Dishevelled activates phospholipase C (PLC), which increases intracellular Ca²⁺ levels.
Increased Ca²⁺ activates calmodulin-dependent protein kinase (CaMK) and PKC, which influence cellular responses.
Calcium and other signaling molecules activate downstream effectors, such as NFAT (nuclear factor of activated T-cells), leading to changes in gene expression.
