The PR65 subunit of protein phosphatase 2A serves as a scaffolding molecule to coordinate the assembly of the catalytic subunit and a variable regulatory B subunit. PP2A exists in several trimeric forms, all of which consist of a core composed of a catalytic subunit associated with a 65 kDa regulatory subunit (PR65) (subunit A). The core complex associates with a third, variable subunit (subunit B), which confers distinct properties to the holoenzyme. Expression varies in tissues throughout development. Highly distributed expression in early embryos. In late embryonal development, found at high levels in nervous system and gonads. In third instar larvae, found in brain, imaginal disks and salivary glands. Expressed both maternally and zygotically. Expressed at lower levels in larvae and adult. Each HEAT repeat appears to consist of two alpha helices joined by a hydrophilic region, the intrarepeat loop. The repeat units may be arranged laterally to form a rod-like structure. Belongs to the phosphatase 2A regulatory subunit A family. Intron retention.