The identification of a second actin-binding region in spinophilin/neurabin II

Anthony P. Barnes, F. Donelson Smith, Hendrika M. VanDongen, Antonius M.J. VanDongen, Sharon L. Milgram

Research output: Contribution to journalArticlepeer-review

15 Scopus citations


Spinophilin/neurabin II is an actin-associated scaffolding protein enriched in the dendritic spines of neurons. Previously, the actin-binding domain (ABD) of spinophilin was localized to a domain between amino acids (aa) 1 and 154. In a mass spectrometry screen for spinophilin-binding proteins, we have identified an additional actin-binding region between aa 151 and 282. F-actin co-sedimentation and GST affinity chromotography experiments further substantiate this result. Phalloidin staining of Rat2 fibroblasts transiently expressing GFP-spinophilin deletion constructs indicates co-localization with a subset of actin. Regions of spinophilin that lack the revised ABD (aa 1-230) do not co-localize with phalloidin-labeled actin, suggesting that the actin-binding domain contributes to directing the subcellular distribution of spinophilin. Targeting experiments using primary hippocampal cultures indicate that only the first actin-binding site contributes to dendritic spine localization. The second ABD targets to spines inefficiently and thus may interact with and affect actin filaments in a different manner than the first ABD.

Original languageEnglish (US)
Pages (from-to)105-113
Number of pages9
JournalMolecular Brain Research
Issue number2
StatePublished - May 19 2004
Externally publishedYes


  • Actin cytoskeleton
  • Actin-binding domain
  • Cellular and Molecular Biology
  • Cytoskeleton Transport and membrane targeting
  • Mass spectrometry
  • Neurabin
  • Spinophilin

ASJC Scopus subject areas

  • Molecular Biology
  • Cellular and Molecular Neuroscience


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