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PubMed · 10567243

Synapsins as major neuronal Ca2+/S100A1-interacting proteins.

J Heierhorst·K I Mitchelhill·R J Mann·T Tiganis·A J Czernik·P Greengard·B E Kemp
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Abstract

The mammalian S100A1 protein can activate the invertebrate myosin-associated giant protein kinase twitchin in a Ca(2+)-dependent manner by more than 1000-fold in vitro; however, no mammalian S100-dependent protein kinases are known. In an attempt to identify novel mammalian Ca(2+)/S100A1-regulated protein kinases, brain extracts were subjected to combined Ca(2+)-dependent affinity chromatography with S100A1 and an ATP analogue. This resulted in the purification to near-homogeneity of the four major synapsin isoforms Ia, Ib, IIa and IIb. All four synapsins were specifically affinity-labelled with the ATP analogue 5'-p-fluorosulphonylbenzoyladenosine. S100A1 bound to immobilized synapsin IIa in BIAcore experiments in a Ca(2+)-dependent and Zn(2+)-enhanced manner with submicromolar affinity; this interaction could be competed for with synthetic peptides of the proposed S100A1-binding sites of synapsin. Double-labelling confocal immunofluorescence microscopy demonstrated that synapsins and S100A1 are both present in the soma and neurites of PC12 cells, indicating their potential to interact in neurons in vivo.

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Adenosine TriphosphateAmino Acid SequenceAnimalsBrain ChemistryCalciumCalcium-Binding ProteinsCell CompartmentationChromatography, AffinityMolecular Sequence DataNeuritesNeuronsPC12 CellsProtein BindingProtein IsoformsRatsS100 ProteinsSequence Analysis, ProteinSynapsinsJournal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, P.H.S.

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J Heierhorst, K I Mitchelhill, R J Mann, T Tiganis, A J Czernik, P Greengard, B E Kemp. 1999-12-01. Synapsins as major neuronal Ca2+/S100A1-interacting proteins.. https://pubmed.ncbi.nlm.nih.gov/10567243/

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