The main topic of the text is the Mitogen-activated protein kinases (MAPK) signaling pathways and their roles in cellular processes. MAPKs are crucial for cellular communication, responding to signals that regulate cell fate, stress adaptation, and development. The text delves into various MAPK pathways, including ERK1/2, p38, JNK, and ERK5, highlighting their unique functions in mammals. It also discusses the diverse roles of MAPK pathways in yeast and plant defense, emphasizing their importance in different biological contexts.
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MAP kinases are part of a hierarchical network that responds to various signals
Ligand Binding
MAP kinases are activated through ligand binding, disrupting their autoinhibited state
Cell Membrane
MAP kinases are activated at the cell membrane, a hub for numerous signaling molecules
Dimerization
MAP kinases engage in dimerization to facilitate their enzymatic function
MAP kinases phosphorylate MAP kinase kinases, culminating in a signaling relay
The ERK1/2 pathway is predominantly activated by Raf proteins following stimulation by growth factors
MKK1 and MKK2
The ERK1/2 pathway specifically targets MKK1 and MKK2 for activation
RSK Kinases and Elk-1
The ERK1/2 pathway phosphorylates RSK kinases and the transcription factor Elk-1
The ERK1/2 pathway maintains precise control over cellular responses to growth signals
The p38 and JNK MAPK pathways exhibit significant overlap in their activators and are activated by stress-related stimuli
The p38 and JNK pathways exhibit cross-talk due to their shared components
c-Jun and NFAT4
The JNK pathway targets specific substrates such as c-Jun and NFAT4 for phosphorylation
MK2 and MK3
The p38 pathway uniquely phosphorylates targets like MK2 and MK3
The distinct substrates for each pathway ensure a comprehensive cellular response to stress
The ERK5 pathway is activated by the upstream kinase MKK5, which is unique to this pathway
PB1 Domains
The specificity of the ERK5 pathway is attributed to the unique PB1 domains of its components
The ERK5 pathway is critical for vascular development and cardiac morphogenesis, and its inactivation results in embryonic lethality
The ERK5 pathway is also essential for plant development and is implicated in developmental disorders in mammals
00
In cellular communication, ______ are crucial for managing responses to various signals.
Mitogen-activated protein kinases (MAPKs)
01
Key ______ such as c-Raf, MEKK4, and MLK3, are activated by ligand binding which interrupts their autoinhibited state.
MAP kinase kinase kinases (MAP3Ks)
02
The activation of MAP3Ks often leads to their ______, an essential step for their enzymatic activity.
homo- or heterodimerization
