Arginine methylation of Puf4 drives diverse protein functions

Abstract

The evolutionarily conserved Pumilio domain-containing RNA binding proteins (RBPs) are involved in many steps of post-transcriptional gene regulation, including RNA stability, polyadenylation, deadenylation, and translation. RBPs are post-translationally modified by methylation of arginine/glycine-rich domains, though the consequences of these modifications are not well known. We determined the arginine methylation and phosphorylation landscape of the Pumilio domain-containing RBP Puf4 from the basidiomycete fungus Cryptococcus neoformans. We found that methyl-deficient Puf4 mutants do not complement critical PUF4 deletion phenotypes, such as resistances to endoplasmic reticulum stress and antifungals, and cell wall remodeling. Methyl-deficient mutants also exhibit unique RNA and protein interactions. Lastly, we identified intra-protein cross talk between post-translationally modified methylated and phosphorylated residues. Overall, we show that post-translational modifications, particularly arginine methylation, of Puf4 regulate the functions of this RBP.

Calcineurin contributes to RNAi-mediated transgene silencing and small interfering RNA production in the human fungal pathogenCryptococcus neoformans

“…RNA interactions of Puf4 involve genes required for cell wall synthesis, drug resistance, as well as regulating gene expression. More importantly, Puf4 immuno-precipitation also revealed a direct interaction with Ago1 (K alem et al . 2022).…”

“…We also identified that deletion of Puf4 results in enhanced silencing by approximately three-fold and this is the first gene whose mutation has been identified to enhance silencing. Puf4 belongs to the Pumilio and Fem-3 (PUF) family of mRNA binding factors and has been shown to bind to several RNAs in C. neoformans (KALEM et al 2021;KALEM et al 2022). RNA interactions of Puf4 involve genes required for cell wall synthesis, drug resistance, as well as regulating gene expression.…”

“…Puf4 belongs to the Pumilio and Fem-3 (PUF) family of mRNA binding factors and has been shown to bind to several RNAs in C. neoformans (K alem et al . 2021; K alem et al . 2022).…”