The sigma-2 receptor is a sigma receptor

Sigma receptor

The sigma receptors σ1 and σ2 bind to ligands such as 4-PPBP, SA 4503, ditolylguanidine, dimethyltryptamine and siramesine.- Classification :...

 which preferentially binds to siramesine

Siramesine

Siramesine is a sigma receptor agonist, selective for the σ2 subtype. In animal studies, siramesine has been shown to produce anxiolytic and antidepressant effects...

 and PB28

PB28

PB-28 is an agonist of the sigma-2 receptor.It is derived from cyclohexylpiperazine....

. Unlike sigma-1 receptor

Sigma-1 receptor

The sigma-1 receptor is a chaperone protein at the endoplasmatic reticulum that modulates calcium signaling through the IP3 receptor. In humans, the sigma-1 receptor is encoded by the SIGMAR1 gene....

, it has not yet been cloned.

Activation of the receptor can cause apoptosis

Apoptosis

Apoptosis is the process of programmed cell death that may occur in multicellular organisms. Biochemical events lead to characteristic cell changes and death. These changes include blebbing, cell shrinkage, nuclear fragmentation, chromatin condensation, and chromosomal DNA fragmentation...

. A pharmacophore

Pharmacophore

thumb|right|300px|An example of a pharmacophore model.A pharmacophore is an abstract description of molecular features which are necessary for molecular recognition of a ligand by a biological macromolecule....

model based on benzooxazolone derivatives.

Sigma-2 ligand binding in vitro

Tumor cells were incubated with 10 nM of SW120 (a fluorescent-labeled sigma-2 receptor ligand) for 30 minutes. HPDE cells were used as a normal control. To demonstrate the specificity of SW120 for Sigma-2 receptor binding, 10μM of SV95 (Sigma-2 ligand) or (+)-pentazocine (sigma-1 receptor ligand) were added to cells 30 minutes prior to SW120 treatment. All lines were then washed 3 times with PBS and evaluated by flow cytometry.