DLG1
Description
The DLG1 (discs large MAGUK scaffold protein 1) is a protein-coding gene located on chromosome 3.
Discs large homolog 1 (DLG1), also known as synapse-associated protein 97 or SAP97, is a scaffold protein that in humans is encoded by the SAP97 gene. SAP97 is a mammalian MAGUK-family member protein that is similar to the Drosophila protein Dlg1 (the protein is alternatively referred to as hDlg1, and the human gene is DLG1). SAP97 is expressed throughout the body in epithelial cells. In the brain it is involved in the trafficking of ionotropic receptors from the endoplasmic reticulum to the plasma membrane, and may be involved in the trafficking AMPAR during synaptic plasticity.
== Function == SAP97 is expressed throughout the body in epithelial cells, including the kidney and brain. There is some evidence that SAP97 regulates cell-to-cell adhesion during cell death, and may interact with HPV. In the brain, SAP97's function is involved in the trafficking of transmembrane receptors from the ER to the plasma membrane. SAP97's function has been investigated by reducing its expression by knockout or increasing its expression heterologously. Mice in which the SAP97 gene has been knocked out die perinatally, have a cleft palate, and deficiencies in renal function. Overexpression of SAP97 in mammalian neurons leads to increased synaptic strength.
== Clinical significance == Mutations in DLG1 are associated to Crohn's disease.
DLG1 is a critical multidomain scaffolding protein, essential for proper development. It orchestrates the assembly of channels, receptors, and signaling molecules within specific regions of the plasma membrane in polarized cells. DLG1 potentially contributes to adherens junction formation, signal transduction, cell proliferation, synaptogenesis, and lymphocyte activation. It fine-tunes the excitability of cardiac myocytes by controlling the activity of Kv4 channels and serves as a functional regulator of Kv1.5 channel. During long-term depression in hippocampal neurons, DLG1 recruits ADAM10 to the plasma membrane.
DLG1 is also known as DLGH1, SAP-97, SAP97, hdlg.
