Genetic dissection of the Mastl-Arpp19/Ensa-PP2A-B55δ pathway in mammalian cells

Abstract

Mastl is an essential kinase required for inhibition of the phosphatase activity directed toward Cdk1/cyclin B substrates during mitosis. Mastl phosphorylates two small evolutionarily conserved proteins, Arpp19 and Ensa converting them into strong inhibitors of PP2A-B55δ. Mastl-Arpp19/Ensa-PP2A regulatory pathway has been mainly studied in Xenopus egg extracts and Drosophila using biochemical and genetic approaches. Studies in mammalian cells and genetically modified mouse models have suggested distinct but important functions for Arpp19 and Ensa, in mitosis and S-phase, respectively. A detailed comparative analysis of the Arpp19 and Ensa functions in mammalian cells has not been performed.

Keywords

• arpp19
• ensa
• greatwall
• mastl
• mitosis
• pp2a-b55δ