Synaptic vesicles in electromotoneurones. I. Axonal transport, site of transmitter uptake and processing of a core proteoglycan during maturation.
AUTOR(ES)
Kiene, M L
RESUMO
We were able by using an in vivo pulse-label technique to trace part of the life cycle of a secretory organelle, the acetylcholine-storing synaptic vesicle from electromotoneurones of Torpedo marmorata. This technique uses [35S]sulphate incorporation into the cell bodies of the electromotoneurones which results in radioactive labelling of a synaptic vesicle heparansulphate proteoglycan--a major core component. Vesicles are anterogradely transported in the axons at a fast rate as 'empty' organelles (VP0 population). In the nerve terminal, maturation of the granule to a population (VP1) fully charged with acetylcholine and ATP occurs. Finally after a longer time interval a change to a third population (VP2) is observed. This population is reduced in diameter as compared to VP0 and VP1 suggesting, in agreement with earlier reports, that it has undergone exo-endocytosis. The changes from VP0 to VP1 and VP2 are accompanied by a degradation of the core proteoglycan as measured by gel filtration of the 35S-labelled compound. The results show that vesicles are axonally transported as preformed organelles, exist in the neurone at least in three different populations and that the nerve terminal is the major site of transmitter uptake.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=553620Documentos Relacionados
- Synaptic vesicles in electromotoneurones. II. Heterogeneity of populations is expressed in uptake properties; exocytosis and insertion of a core proteoglycan into the extracellular matrix.
- Energy depletion retards the loss of membrane transport during reticulocyte maturation.
- Identification of a heparan sulphate-containing proteoglycan as a specific core component of cholinergic synaptic vesicles from Torpedo marmorata.
- Studies on Effect of Certain Quinones: I. Electron Transport, Photophosphorylation, and CO2 Fixation in Isolated Chloroplasts 1
- Synthesis, intracellular transport, and processing of the precursors for mitochondrial ornithine transcarbamylase and carbamoyl-phosphate synthetase I in isolated hepatocytes.