Abstract
Synapsin I is a neuron-specific phosphoprotein which binds to small synaptic vesicles and actin in a phosphorylation-dependent fashion. We have analyzed the ability of synapsin I to interact with actin monomers and filaments using purified proteins derivatized with fluorescent probes. Synapsin I accelerates the initial rate of actin polymerization and increases the final steady-state levels of polymerized actin. The fraction of total actin polymerized by synapsin I strongly depends on the synapsin I-actin ratio. We have visualized the actin-bundling activity of synapsin I using a non-perturbing method, video-enhanced microscopy of fluoresceinated synapsin I and actin filaments. Our findings suggest that synapsin I exerts a control on the physical characteristics of the cytoskeletal network of the nerve terminal and are consistent with the proposed role of synapsin I in mediating the interaction of synaptic vesicles with actin.
Original language | English |
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Pages (from-to) | 117-122 |
Number of pages | 6 |
Journal | Journal of Physiology Paris |
Volume | 87 |
Issue number | 2 |
DOIs | |
Publication status | Published - 1993 |
Keywords
- actin polymerization
- protein phosphorylation
- pyrenyl-actin
- synaptic vesicles
ASJC Scopus subject areas
- Physiology (medical)
- Neuroscience(all)