Growth Cone Paper Flashcards
What is name of paper?
Chemotropic responses of retinal growth cones mediated by rapid local protein synthesis and degradation
What mediates attraction to netrin-1? repulsion?
DCC; Unc-5
What guidance cues were discussed in the paper?
Netrin-1 and Sema3A are chemotropic attract and repel growth cones
What is main hypothesis?
axon guidance cues mediate growth cone guidance by regulating protein synthesis and degradation
What proteins induce protein synthesis in isolated growth cones?
Sema3A and netrin-1
What proteins induce protein ubiquitination in growth cones?
Netrin-1 and LPA
According to Figure 1, what can prevent Sema3A induced collapse and turning?
Protein synthesis inhibitors. Proves that Sema3A uses protein synthesis to induce turning and growth cone collapse.
According to Figure2, what prevents netrin induced turning?
Protein synthesis inhibiters block turning regardless of whether it is attractive or repulsive.
According to Figure 3, how did isolated growth cones respond to protein synthesis inhibitors?
Growth cone responses to Sema3A and netrin-1 were blocked by protein synthesis inhibitors in isolated growth cones
According to Figure 4, how do the cues stimulate protein synthesis?
Netrin-1 and Sema3A both use TOR kinase to phosphorylate/inactivate translation repressor (elF-4EBP1), thus releasing translation initiation factor (elF-4E)
According to Figure 5, how do proteasome (degradation) inhibitors affect netrin?
Proteasome inhibitors such as LnLL and lactacytsin block netrin-induced turning.
According to Figure 6, how do proteasome inhibitors affect LPA and Sema-3?
LPA and BDNF responses are affected by proteasome inhibitors.
Suggest cAMP mediates collapse
According to Figure 7, how did isolated growth cones respond to proteasome inhibitors.
Proteasome inhibitors block LPA and netrin-1 responses in isolated growth cones. Thus, they stimulate rapid rises in ubiquitin-protein conjugates.
What is the main findings of the papers?
Protein synthesis by Sema3A and Netrin-1 mediates turning and collapse (Sema3A).
Protein degradation by LPA and Netrin-1 mediates turning and collapse (LPA)
What do guidance cues and mRNA encoding protein, RhoA, have in common?
They contribute to local translation of actin mRNA
