RT Journal Article
SR Electronic
T1 Proline-Rich Synapse-Associated Protein-1/Cortactin Binding Protein 1 (ProSAP1/CortBP1) Is a PDZ-Domain Protein Highly Enriched in the Postsynaptic Density
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 6506
OP 6518
DO 10.1523/JNEUROSCI.19-15-06506.1999
VO 19
IS 15
A1 Tobias M. Boeckers
A1 Michael R. Kreutz
A1 Carsten Winter
A1 Werner Zuschratter
A1 Karl-Heinz Smalla
A1 Lydia Sanmarti-Vila
A1 Heike Wex
A1 Kristina Langnaese
A1 Juergen Bockmann
A1 Craig C. Garner
A1 Eckart D. Gundelfinger
YR 1999
UL http://www.jneurosci.org/content/19/15/6506.abstract
AB The postsynaptic density (PSD) is crucially involved in the structural and functional organization of the postsynaptic neurotransmitter reception apparatus. Using antisera against rat brain synaptic junctional protein preparations, we isolated cDNAs coding for proline-rich synapse-associated protein-1 (ProSAP1), a PDZ-domain protein. This protein was found to be identical to the recently described cortactin-binding protein-1 (CortBP1). Homology screening identified a related protein, ProSAP2. Specific antisera raised against a C-terminal fusion construct and a central part of ProSAP1 detect a cluster of immunoreactive bands of 180 kDa in the particulate fraction of rat brain homogenates that copurify with the PSD fraction. Transcripts and immunoreactivity are widely distributed in the brain and are upregulated during the period of synapse formation in the brain. In addition, two short N-terminal insertions are detected; they are differentially regulated during brain development. Confocal microscopy of hippocampal neurons showed that ProSAP1 is predominantly localized in synapses, and immunoelectron microscopy in situ revealed a strong association with PSDs of hippocampal excitatory synapses. The accumulation of ProSAP1 at synaptic structures was analyzed in the developing cerebral cortex. During early postnatal development, strong immunoreactivity is detectable in neurites and somata, whereas from postnatal day 10 (P10) onward a punctate staining is observed. At the ultrastructural level, the immunoreactivity accumulates at developing PSDs starting from P8. Both interaction with the actin-binding protein cortactin and early appearance at postsynaptic sites suggest that ProSAP1/CortBP1 may be involved in the assembly of the PSD during neuronal differentiation.