Enables small GTPase binding activity. Involved in generation of neurons; positive regulation of GTPase activity; and positive regulation of dendritic spine development. Located in dendrite; perinuclear region of cytoplasm; and synapse. Is active in glutamatergic synapse and postsynaptic density, intracellular component. Colocalizes with ruffle membrane. Human ortholog(s) of this gene implicated in Rett syndrome; developmental and epileptic encephalopathy 2; intellectual disability; and visual epilepsy. Orthologous to human CDKL5 (cyclin dependent kinase like 5). [provided by Alliance of Genome Resources, Apr 2022]