22 - Signaling and Gene Regulation & Control of Gene Transcription Flashcards
What is the major takeaway of cell signaling?
Signaling pathways lead to changes in gene expression
True or false: almost all cells in an organism are genetically identical
True: they all have the same DNA
What produces differences between cell types?
Differences in gene expression
What is differential gene expression?
The expression of different genes by cells within the same genome
True or false: gene expression only refers to translation
False: it includes everything from chromatin remodeling to protein degradation
Which steps (6) can gene expression be controlled?
- Transcriptional control
- RNA processing control
- RNA transport and localization control
- Translation control
- mRNA degradation control
- Protein activity control
What characteristics describe signaling that alters protein function/activation state?
More rapid, less energy, more quickly reversible
What characteristics describe signaling that alters protein levels?
Less rapid, more energy, less quickly reversible
What is an example of translational control?
ERK signaling being compartmentalized within the cell
What scaffold localizes ERK at the golgi?
Sef
What is a polysome?
mRNA transcript with multiple ribosomes on it
What does MNK1 do?
It phosphorylates eIF-4E to initiate protein synthesis
How is MNK1 activated?
Through phosphorylation by ERK and p38
What happens when 4E-BP1 is phosphorylated?
It releases eIF4E, which can help form the initiation complex
What does MNK stand for?
MAP kinase interacting kinase
How is 4E activated?
Through phosphorylation by MNK
What is needed for 4E to initiate protein synthesis?
- It needs to be phosphorylated by MNK (through p38/ERK)
2. It needs to be localized by being released from p4E-BP1
What does 4E-BP1 stand for?
4E binding protein 1
What phosphorylates 4E-BP1?
the mTORC1
What does mTORC1 stand for?
mTOR complex 1
How is mTOR activated?
Through phosphorylation by Akt
What is cap-dependent mRNA translation?
A 5’ cap is needed on the mRNA to form the proper rings for translation
What does IRES stand for?
Internal ribosome entry site
What can inhibit TOR?
Cancer cells, viruses, and stress