Believed to act as a modulator of nicotinic acetylcholine receptors (nAChRs) activity. In vitro increases receptor desensitization and decreases affinity for ACh of alpha-4:beta-2-containing nAChRs (PubMed:19246390). May play a role in the intracellular trafficking of alpha-4:beta-2 and alpha-7-containing nAChRs and may inhibit their expression at the cell surface (PubMed:26276394, PubMed:25716842). May be involved in the control of anxiety (PubMed:19246390). Interacts with CHRNA4 and nAChRs containing alpha-4:beta-2 (CHRNA4:CHRNB2) and alpha-7 (CHRNA7) subunits. Preferentially expressed in the nervous system. Expressed in embryonic and postnatal postmitotic central and peripheral neurons including subpopulations of motor neurons, sensory neurons, interneurons and neurons of the autonomous nervous system. Expressed around the growing nerves in the limb bud (PubMed:16236524). Expressed at high levels in specific brain regions such as the prefrontal cortex, amygdala, hippocampus, mediodorsal thalamus, dentate gyrus and specific brainstem nuclei (at protein level) (PubMed:19246390). Increased anxiety-like behaviors. Increased glutamatergic activity in response to nicotine in layer V neurons of the medial prefrontal cortex.