Recombinant Human SAP97 protein (ab152336)

Essential multidomain scaffolding protein required for normal development (By similarity). Recruits channels, receptors and signaling molecules to discrete plasma membrane domains in polarized cells. May play a role in adherens junction assembly, signal transduction, cell proliferation, synaptogenesis and lymphocyte activation. Regulates the excitability of cardiac myocytes by modulating the functional expression of Kv4 channels. Functional regulator of Kv1.5 channel.

Abundantly expressed in atrial myocardium (at protein level). Expressed in lung fibroblasts, cervical epithelial and B-cells (at protein level). Widely expressed, with isoforms displaying different expression profiles.

Belongs to the MAGUK family.
Contains 1 guanylate kinase-like domain.
Contains 1 L27 domain.
Contains 3 PDZ (DHR) domains.
Contains 1 SH3 domain.

The alternatively spliced domain I3 corresponding to amino acids (636-669) of isoform 4 is an EPB41 binding site mediating association to membranes in polarized and non-polarized cells.
The PDZ domains may also mediate association to membranes by binding to EPB41 and ADGRA2 together with the L27 domain that binds CASK and DLG2.
The L27 domain may regulate DLG1 self-association. The N-terminal alternatively spliced region is capable of binding several SH3 domains and also moderates the level of protein oligomerization.

Phosphorylated by MAPK12. Phosphorylation of Ser-232 regulates association with GRIN2A.

Membrane. Basolateral cell membrane. Endoplasmic reticulum membrane. Cell junction, synapse, postsynaptic cell membrane, postsynaptic density. Cell junction, synapse. Cell membrane, sarcolemma. Colocalizes with EPB41 at regions of intercellular contacts. Basolateral in epithelial cells. May also associate with endoplasmic reticulum membranes. Mainly found in neurons soma, moderately found at postsynaptic densities (By similarity).