Enables DNA-binding transcription activator activity, RNA polymerase II-specific and RNA polymerase II cis-regulatory region sequence-specific DNA binding activity. Contributes to transcription cis-regulatory region binding activity. Involved in positive regulation of transcription by RNA polymerase II. Acts upstream of or within positive regulation of stem cell proliferation; positive regulation of transcription, DNA-templated; and regulation of stem cell population maintenance. Located in nucleus. Is expressed in several structures, including branchial arch; cerebral cortex; early conceptus; genitourinary system; and hemolymphoid system gland. Orthologous to human NFYA (nuclear transcription factor Y subunit alpha). [provided by Alliance of Genome Resources, Apr 2022]