Mapk Flashcards
Describe the activation mechanism of the MAPK pathway.
Activated RTKs recruit adaptor proteins, which activate Ras, leading to the sequential phosphorylation of Raf, MEK, and MAPK.
What is the significance of scaffold proteins in signal transduction?
Scaffold proteins organize and facilitate the interaction of signaling molecules, enhancing the specificity and efficiency of signal transduction.
Explain how the PI3K/Akt pathway influences cell survival.
PI3K activates Akt through phosphorylation, promoting cell survival by inhibiting apoptotic processes and stimulating growth-related pathways.
What role does cyclic AMP (cAMP) play in signal transduction?
cAMP acts as a second messenger, activating protein kinase A (PKA) which then phosphorylates target proteins to elicit cellular responses.
How do G-protein coupled receptors (GPCRs) transmit signals?
GPCRs activate heterotrimeric G-proteins upon ligand binding, which then regulate various downstream effectors like adenylyl cyclase and phospholipase C.
How does calcium function as a second messenger in cells?
Calcium ions, released from intracellular stores or entering through channels, activate proteins such as calmodulin, which regulate various cellular activities.
Describe the role of phospholipase C (PLC) in signal transduction.
PLC hydrolyzes PIP2 to produce IP3 and DAG, leading to the release of Ca2+ and activation of protein kinase C (PKC), respectively.
How is signal specificity achieved in the MAPK pathway?
Specificity is achieved through the use of scaffold proteins, spatial compartmentalization, and selective activation of pathway components.
