Association of synapse-associated protein 90/postsynaptic density-95-associated protein (SAPAP) with neurofilaments

作者：Hirao K; Hata Y; Deguchi M; Yao I; Ogura M; Rokukawa C; Kawabe H; Mizoguchi A; Takai Y^*

来源：Genes to Cells, 2000, 5(3): 203-210.

DOI：10.1046/j.1365-2443.2000.00318.x

Background: Synapse-associated protein (SAP) 90/Postsynaptic density (PSD)-95-associated protein (SAPAP) (also called Guanylate kinase-associated protein/hDLG-associated protein) interacts with the guanylate kinase domains of PSD-95 and synaptic scaffolding molecule (S-SCAM) via the middle region containing 5 repeats of 14 amino acids. SAPAP also binds the recently identified proteins, nArgBP2 and synamon (also called Shank 1a), via the proline-rich region and the C-terminus, respectively. SAPAP is highly enriched in the Triton X-100-insoluble PSD fraction, and recruits PSD-95 into the Triton X-100-insoluble fraction in transfected cells. We have further characterized here the Triton X-100-insolubility of SAPAP and tried to identify the Triton X-100-insoluble structures which SAPAP interacts with.
Results: N-Methyl-d-aspartate receptors were recruited into the Triton X-100-insoluble fraction with PSD-95 by SAPAP. The N-terminal region of SAPAP was Triton X-100-insoluble, whereas the middle and C-terminal regions were Triton X-100-soluble. We identified proteins interacting with S-35-methionine-labelled SAPAP in the overlay assay, determined their amino acid sequences, and found them to be neurofilaments. SAPAP interacted with neurofilaments via the N-terminal region, was co-immunoprecipitated with neurofilaments from the rat brain, and co-localized with neurofilaments in transfected cells.
Conclusion: SAPAP associates with neurofilaments via the N-terminal region and may link various components of the PSD to neurofilaments.

• 出版日期2000-3