Neuronal Growth Cone Size-Dependent and -Independent Parameters of Microtubule Polymerization

CLIPs regulate neuronal polarization through microtubule and growth cone dynamics

Cytoplasmic linker proteins regulate neuronal polarization through microtubule and growth cone dynamics.

Axon formation is a hallmark of initial neuronal polarization. This process is thought to be regulated by enhanced microtubule stability in the subsequent axon and changes in actin dynamics in the future axonal growth cone. Here, we show that the microtubule end-binding proteins cytoplasmic linker protein (CLIP)-115 and CLIP-170 were enriched in the axonal growth cone and extended into the acti...

Kinesin Kip2 enhances microtubule growth in vitro through length-dependent feedback on polymerization and catastrophe

The size and position of mitotic spindles is determined by the lengths of their constituent microtubules. Regulation of microtubule length requires feedback to set the balance between growth and shrinkage. Whereas negative feedback mechanisms for microtubule length control, based on depolymerizing kinesins and severing proteins, have been studied extensively, positive feedback mechanisms are no...

Myosin II activity facilitates microtubule bundling in the neuronal growth cone neck.

The cell biological processes underlying axon growth and guidance are still not well understood. An outstanding question is how a new segment of the axon shaft is formed in the wake of neuronal growth cone advance. For this to occur, the highly dynamic, splayed-out microtubule (MT) arrays characteristic of the growth cone must be consolidated (bundled together) to form the core of the axon shaf...

Rho-Dependent Contractile Responses in the Neuronal Growth Cone Are Independent of Classical Peripheral Retrograde Actin Flow

Rho family GTPases have been implicated in neuronal growth cone guidance; however, the underlying cytoskeletal mechanisms are unclear. We have used multimode fluorescent speckle microscopy (FSM) to directly address this problem. We report that actin arcs that form in the transition zone are incorporated into central actin bundles in the C domain. These actin structures are Rho/Rho Kinase (ROCK)...