PDZ domain 4 of glutamate receptor-interacting protein 1 (GRIP1) and GRIP2, and related domains
PDZ (PSD-95 (Postsynaptic density protein 95), Dlg (Discs large protein), and ZO-1 (Zonula occludens-1)) domain of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) binding proteins GRIP1 (ABP/GRIP2) and GRIP2, and related domains. GRIP1 and GRIP2 each have 7 PDZ domains. The interaction of GRIP1 and GRIP2 with GluA2/3 (AMPAR subunit) regulates AMPAR trafficking and synaptic targeting. GRIP1 has an essential role in regulating AMPAR trafficking during synaptic plasticity and learning and memory. GRIP1 and GRIP2 interact with a variety of other proteins associated with protein trafficking and internalization, for example GRIP1 also interacts with KIF5 (also known as kinesin 1), EphB receptors, scaffold protein liprin-alpha, and the rasGEF GRASP-1. PDZ domains usually bind in a sequence-specific manner to short peptide sequences located at the C-terminal end of their partner proteins (known as PDZ binding motifs). The PDZ superfamily includes canonical PDZ domains as well as those with circular permutations and domain swapping mediated by beta-strands. This GRIP family PDZ4 domain is a canonical PDZ domain containing six beta-strands A-F and two alpha-helices (alpha-helix 1 and 2), arranged in the order: beta-strands A, B, C, alpha-helix 1, beta-strands D, E, alpha-helix 2 and beta-strand F.
Feature 1:peptide binding site [polypeptide binding site]
Evidence:
Comment:based on canonical PDZ domains with structure
Comment:PDZ domains specifically recognize and bind to short C-terminal peptide motifs, but can also recognize internal peptide motifs and certain lipids
Comment:both the forth and fifth PDZ domains (PDZ4 and PDZ5) of GRIP are required for effective binding to glutamate receptor subunits 2 and 3 (GluR2/3); GRIP PDZ4 contains a deformed PDZ-binding site that is unlikely to bind to carboxyl peptides but has the ancillary function of stabilizing the PDZ5 structure
Jiyao W et al.(2023). "The conserved domain database in 2023.",