Synapsin I is a spectrin-binding protein immunologically related to erythrocyte protein 4.1.

Journal Article (Journal Article)

The membrane-associated cytoskeleton is considered to be the apparatus by which cells regulate the properties of their plasma membranes, although recent evidence has indicated additional roles for the proteins of this structure, including an involvement in intracellular transport and exocytosis (see refs 1-3 for review). Of the membrane skeletal proteins, to date only spectrin (fodrin) and ankyrin have been purified and characterized from non-erythroid sources. Protein 4.1 in the red cell is a spectrin-binding protein that enhances the binding of spectrin to actin and can apparently bind to at least one transmembrane protein Immunoreactive forms of 4.1 have been detected in several cell types, including brain. Here we report the purification of brain 4.1 on the basis of its cross-reactivity with erythrocyte 4.1 and spectrin-binding activity. We further show that brain 4.1 is identical to the synaptic vesicle protein, synapsin I, one of the brain's major substrates for cyclic AMP and Ca2+-calmodulin-dependent kinases. Spectrin and synapsin are present in brain homogenates in an approximately 1:1 molar ratio. Although synapsin I has been implicated in synaptic transmission, no activity has been previously ascribed to it.

Full Text

Duke Authors

Cited Authors

  • Baines, AJ; Bennett, V

Published Date

  • May 30, 1985

Published In

Volume / Issue

  • 315 / 6018

Start / End Page

  • 410 - 413

PubMed ID

  • 3923367

International Standard Serial Number (ISSN)

  • 0028-0836

Digital Object Identifier (DOI)

  • 10.1038/315410a0


  • eng

Conference Location

  • England