Fast axonal transport in the presence of high Ca2+: evidence that microtubules are not required.
AUTOR(ES)
Brady, S T
RESUMO
Microtubules have long been associated with the mechanism of fast axoplasmic transport, although experimental evidence to support an involvement has been equivocal. Electron microscopic studies demonstrated that incubation of the axons of excised rat sciatic nerves in media containing 75 mM Ca2+ caused complete loss of microtubules within 6 hr. To evaluate the role of microtubules in fast anterograde transport, studies of transport in nerves exposed to these conditions were undertaken. Prior to measurement of axoplasmic transport, nerves ligated distal to the dorsal root ganglia were preincubated in vitro in 75 mM Ca2+ for 0-6 hr. Fast axonal transport was subsequently monitored by measuring the amount of trichloroacetic acid-insoluble radioactivity that accumulated at the ligature after incubation for 12-18 hr with L-[3H]proline. Nerves in which microtubules had been depolymerized by preincubation in high Ca2+ maintained control levels of transport. We conclude that intact microtubules are not required for fast anterograde axoplasmic transport.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=350181Documentos Relacionados
- V(D)J recombination: evidence that a replicative mechanism is not required.
- Axonal transport of a subclass of tau proteins: evidence for the regional differentiation of microtubules in neurons.
- The interaction between cytoplasmic dynein and dynactin is required for fast axonal transport
- Microtubule-binding drugs offset tau sequestration by stabilizing microtubules and reversing fast axonal transport deficits in a tauopathy model
- Cytoplasmic Dynein, the Dynactin Complex, and Kinesin Are Interdependent and Essential for Fast Axonal Transport