Abstract
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 language | English (US) |
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Pages (from-to) | 105-113 |
Number of pages | 9 |
Journal | Molecular Brain Research |
Volume | 124 |
Issue number | 2 |
DOIs | |
State | Published - May 19 2004 |
Externally published | Yes |
Keywords
- 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