Involved in plasma membrane dynamics and cell process formation. Isoform 1 and isoform 2 are necessary for axonal and dendritic filopodia induction, for dendritic spine maturation and synapse formation in a palmitoylation-dependent manner. Interacts with dopamine receptor DRD3. Translocation to the plasma membrane is enhanced upon stimulation of neuronal activity. Expression is highest in brain, intermediate in adrenal gland and kidney, and much lower or undetectable in other tissues. Isoform 1 is the predominant isoform in most tissues except brain and kidney where isoform 2 predominates. In brain, expression is highest in neonates and declines to approximately 50% in adults. Isoform 2 is the predominant isoform in neonates with isoform 1 being barely detectable at this stage. Levels of isoform 1 increase with age, with the most pronounced increase between postnatal days 10 and 20. Mutagenesis of Cys-333, Cys-335 and Cys-336 to Ser inhibit filopodia and spines induction and synapse maturation. Belongs to the paralemmin family.