Proline-rich synapse-associated proteins ProSAP1 and ProSAP2 interact with synaptic proteins of the SAPAP/GKAP family.
We have recently isolated a novel proline-rich synapse-associated protein-1 (ProSAP1) that is highly enriched in postsynaptic density (PSD). A closely related multidomain protein, ProSAP2, shares a highly conserved PDZ (PSD-95/discs-large/ZO-1) domain (80% identity), a ppI domain that mediates the interaction with cortactin, and a C-terminal SAM (sterile alpha-motif) domain. In addition, ProSAP2 codes for five ankyrin repeats and a SH3 (Src homology 3) domain. Transcripts for both proteins are coexpressed in many regions of rat brain, but show a distinct expression pattern in the cerebellum. Using the PDZ domains of ProSAP1 and 2 as bait in the yeast two-hybrid system, we isolated several clones of the SAPAP/GKAP (SAP90/PSD-95-associated protein/guanylate kinase-associated protein) family. The association of the proteins was verified by coimmunoprecipitation and cotransfection in HEK cells. Therefore, proteins of the ProSAP family represent a novel link between SAP90/PSD-95 bound membrane receptors and the cytoskeleton at glutamatergic synapses of the central nervous system.
Boeckers
T M
TM
Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, 39118, Germany. bockers@uni-muenster.de
Winter
C
C
Smalla
K H
KH
Kreutz
M R
MR
Bockmann
J
J
Seidenbecher
C
C
Garner
C C
CC
Gundelfinger
E D
ED
D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000378:metabolism; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D003599:Cytoskeleton / Q000378:metabolism; D066298:In Vitro Techniques; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D000074407:SAP90-PSD95 Associated Proteins; D017386:Sequence Homology, Amino Acid; D013570:Synaptic Membranes / Q000378:metabolism
D002352:Carrier Proteins; D009419:Nerve Tissue Proteins; D000074407:SAP90-PSD95 Associated Proteins; C485686:Shank2 protein, rat