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37 Cards in this Set
- Front
- Back
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What is the role of BMP-4? |
1. Suppress neuronal differentiation 2. Promote epidermal differentiation |
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What secretes BMO antagonists? |
1. Organizer region in the mesoderm |
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What are the BMP antagonists? |
1. Noggin 2. Chordin 3. Follistatin |
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What is the MOA of noggin? |
1. Binds to BMP-4, antagonizes action |
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What is BMP-4? |
1. Peptide that binds to a serine threonine protein kinase receptor 2. Activates SMAD transcription factors |
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What is the role of neurotrophins? |
1. Promote cell survival 2. Required for survival of sympathetic and sensory neurons |
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What % of neurons are loss during development? |
1. 50%--- apoptosis |
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What are the hallmarks of necrosis? |
1. Cellular stress/insults 2. Cells swell and burst 3. Leakage of cellular components can be toxic |
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How can you detect chromatin aggregation in apoptosis? |
1. Electrophoresis---- ladder pattern 2. TUNEL assay-- end-labeled DNA with a fluorescent marker |
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What are the potential therapeutic targets of apoptosis drugs? |
1. Parkinson's/Alzheimers 2. Ischemia and hypoxia 3. Caspases 4. Neurotrophins |
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What is the role of TrkB? |
1. Required for survival of some neurons during development 2. Absence leads to neuronal deficits |
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What is the ligand for TRK? |
1. NGF |
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What are the ligands for TRKB? |
1. BDNF 2. NT-4/5 3. NT-3 |
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What is the ligand for TRKC? |
1. NT-3 |
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What are Trks? |
1. Ligand-activated protein tyrosine kinases |
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What pathways can GF/neurotrophins activate? |
1. Ca/diacylgylcerol PKC 2. PI3K/AKT--- cell survival 3. Ras/MAPK--- cell growth or survival |
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What do GFs induce? |
1. Diemrization 2. Autophosphorylation in trans 3. Phosphorylation of the activation loop |
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What can phosphorylation of the activation loop alter? |
1. Substrate binding 2. ATP binding 3. Phosphotransfer rate |
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How is the insulin receptor activated? |
1. Autophosphorylation--- releases the activation loop from the cleft |
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What are the transducers for the BDNF signaling pathways? |
1. Shc and Grb2 |
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What is the signaling enzyme for BDNF? |
1. PLC-y |
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What is the role of SOS? |
1. Activates Ras GDP to Ras GTP |
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What does active Ras do? |
1. Binds Raf1--- serine/threonine kinase 2. Raf1 phosphorylates MEK |
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What is the role of MEK? |
1. Phosphorylates MAPK--- activation 2. MAPK is translocated to the nucleus |
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What is the role of MAPK? |
1. Causes or represses gene expression |
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What causes NF1? |
1. Mutation in tumor suppression gene--- NF1 |
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What is the presentation of NF1? |
1. Neurofibromas--- crest-cell derived skin tumors |
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What does NF1 develop? |
1. GAP hydrolyzes Ras GTP to RAS GDP (normally), leading to normal function 2. Loss of function in NF1 mutation increases Ras activity----- unregulated cell growth |
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What is the whole cycle of Ras activity? |
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To what can the growth cone respond in a developing axon? |
1. Extracellular matrix adhesion 2. Cell surface adhesion 3. Chemoattraction or chemorepulsion 4. Contact inhibition |
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What is the role of Netrin-1? |
1. Binds to DCC--- causes chemoattraction 2. Binds to UNC5H--- causes chemorepulsion |
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What causes attraction in cortical axon guidance? |
1. Activation of D1 receptors 2. cAMP and PPKA increased 3. DCC insertion increased |
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What causes repulsion in cortical axon guidance? |
1. Activation of D2 receptors 2. Decreases cAMP and PKA 3. Increase UNC5 |
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What is the role of agrin? |
1. Triggers the clustering of acetylcholine receptors 2. Necessary for synaptogenesis 3 Increases activity of MuSK |
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What is the role of rapsyn? |
1. Required for clustering of post-synaptic proteins |
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What is the role of neuregulin and ErbB in synaptogenesis? |
1. Neuregulin activation of ErbB tyrosine kinase induces AchR synthesis |
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What inhibits synthesis of AChRs? |
1. Electrical activity from nuclei distant from a synapse |
