Abstract
By using the yeast two-hybrid system we identified a novel protein from the human brain interacting with the C terminus of somatostatin receptor subtype 2. This protein termed somatostatin receptor interacting protein is characterized by a novel domain structure, consisting of six N-terminal ankyrin repeats followed by SH3 and PDZ domains, several proline-rich regions, and a C-terminal sterile alpha motif. It consists of 2185 amino acid residues encoded by a 9-kilobase pair mRNA; several splice variants have been detected in human and rat cDNA libraries. Sequence comparison suggests that the novel multidomain protein, together with cortactin-binding protein, forms a family of cytoskeletal anchoring proteins. Fractionation of rat brain membranes indicated that somatostatin receptor interacting protein is enriched in the postsynaptic density fraction. The interaction of somatostatin receptor subtype 2 with its interacting protein was verified by overlay assays and coimmunoprecipitation experiments from transfected human embryonic kidney cells. Somatostatin receptor subtype 2 and the interacting protein display a striking overlap of their expression patterns in the rat brain. Interestingly, in the hippocampus the mRNA for somatostatin receptor interacting protein was not confined to the cell bodies but was also observed in the molecular layer, suggesting a dendritic localization of this mRNA.
Highlights
Targeting of neurotransmitter receptors to postsynaptic or presynaptic sites is an area that has been widely studied in recent years; a large body of evidence has accumulated showing that many receptors are anchored at their specifc site of action by specialized anchoring proteins, which may link receptors to components of the synaptic structure or the cytoskeleton [1, 2]
Specific Interaction between a Novel PDZ Domain Protein and the C Terminus of the Rat SSTR2—We used the C terminus of the rat SSTR2 as a bait in a yeast two-hybrid screen for potentially interacting proteins [9]; one novel clone of 900 base pairs, termed SSTRIP for somatostatin receptor interacting protein, was obtained from a human cDNA library which interacted with SSTR2 when compared with the empty bait vector or nonrelated control proteins
We report the cloning of human SSTRIP, a protein that interacts with the C terminus of the SSTR2 via a PDZ domain-type interaction
Summary
Targeting of neurotransmitter receptors to postsynaptic or presynaptic sites is an area that has been widely studied in recent years; a large body of evidence has accumulated showing that many receptors are anchored at their specifc site of action by specialized anchoring proteins, which may link receptors to components of the synaptic structure or the cytoskeleton [1, 2]. This is true for inhibitory as well as excitatory receptors of the family of ligand-gated ion channels. The latter defines a novel family of multidomain cytoskeletal anchoring proteins that are highly enriched in the postsynaptic density fraction derived from rat brain
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
