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Effects of synaptic vesicles on actin polymerization.

E Chieregatti·P E Ceccaldi·F Benfenati·F Valtorta
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Abstract

We have analyzed the effects of synaptic vesicles on actin polymerization by using a time-resolved spectrofluorometric assay. We have found that synaptic vesicles have complex effects on the kinetics of actin polymerization, which vary depending on whether the synaptic vesicle-specific phosphoprotein synapsin I is absent or present on their membrane. Synapsin I bound either to synaptic vesicles or to pure phospholipid vesicles exhibits phosphorylation-dependent actin-nucleating activity. Synaptic vesicles depleted of endogenous synapsin I decrease the rate and the final extent of actin polymerization, an effect which is not observed with pure phospholipid vesicles. Thus, the state of association of synapsin I with synaptic vesicles, which is modulated by its state of phosphorylation, may affect actin assembly and the physico-chemical characteristics of the synaptic vesicle microenvironment.

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ActinsAnimalsCattleKineticsMembranes, ArtificialOsmolar ConcentrationPhosphorylationPolymersRatsSpectrometry, FluorescenceSynapsinsSynaptic VesiclesViscosityJournal ArticleResearch Support, Non-U.S. Gov't

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E Chieregatti, P E Ceccaldi, F Benfenati, F Valtorta. 1996-12-02. Effects of synaptic vesicles on actin polymerization.. https://doi.org/10.1016/s0014-5793(96)01240-9

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