Identification by molecular cloning of two cDNA sequences from the plant Brassica napus which are very similar to mammalian protein phosphatases‐1 and ‐2A

Abstract
Two clones encoding protein phosphatase (PP) catalytic subunits have been isolated from a Brassica napus cDNA library screened with rabbit muscle PPlα and PP2Aα cDNAs. The deduced protein sequences are very similar to those of mammalian PPlα and PP2Aα (72% and 79% overall identity, respectively) indicating that they are the plant homologues of PPlα and PP2Aα. This high degree of similarity provides a molecular explanation for the remarkable conservation of the catalytic and regulatory properties between animal and plant protein phosphatases and supports the concept that PP1 and PP2A may be the most highly conserved of known enzymes.