Enables several functions, including Hsp90 protein binding activity; cyclin-dependent protein serine/threonine kinase activator activity; and enzyme binding activity. Involved in several processes, including ephrin receptor signaling pathway; nervous system development; and regulation of cytoskeleton organization. Acts upstream of or within several processes, including G1 to G0 transition involved in cell differentiation; nervous system development; and serine phosphorylation of STAT protein. Located in cytoplasm and nucleus. Is expressed in several structures, including alimentary system; genitourinary system; integumental system; nervous system; and sensory organ. Used to study attention deficit hyperactivity disorder. Human ortholog(s) of this gene implicated in Alzheimer's disease. Orthologous to human CDK5R1 (cyclin dependent kinase 5 regulatory subunit 1). [provided by Alliance of Genome Resources, Apr 2022]