L11 - Growth cones Flashcards
Lamella - actin structure
bundles crosslinked into net
Filopodia - actin structure
large polarised bundles
resting growth cone filopodia
F-actin treadmills, tubulin performs microtubule capture
F-actin accumulation effect
stabilises filopodium, microtubule capture.
What drives growth cone forward movement
stimulus - cytoskeletsl rearrangement
attachment to substrste
Components leading to filopodia extension and microtubule reorientation
molecular clutch, actomyosin-based actin tubulin link
Uncrosslinked f-actin chracteristic
little strength, no net movement = treadmilling
Destabilised F-actin
growth cone collapse
Rho GTPases
molecular switches that respond to extracellular signals
GEFs
switches Rho GTPase ON
Rho GTPases
control formation of actin based structures
Activated Rac and cdc42
positive regulators of axon growth
Activated RhoA
negative regulator of axon growth
Growth requires
assembly and disassembly of actin structures
Semaphorin signalling
alters RhoA/RAC balance
Growth cone extension or collapse defined by
Rho/Rac balance
How does calcium fluxes turn growth cones
calcium regulates Rho GTPases
Growth cone behaviour control -
interactions between pathways controlling the actin cytoskeleton and microtubules