SAP 97 (synapse associated protein of 97 kDa, also called DLG 1) like PSD 95 and SAP 102, is a scaffolding protein of the postsynaptic density. It consists of three type-one PDZ domains and binds selectively to the C-terminus of the GluR1 subunit of AMPA receptors.
SAP 97 is probably involved in the clustering of AMPA receptors at the post-synaptic membrane.
It is also expressed in heart, where it has been shown to be involved in the targeting of voltage gated potassium channels to subpopulations of lipid rafts.