A unique system for regulating mitochondrial mRNA poly(A) status and stability in plants

Abstract

Poly(A) status is the major determinant of mRNA stability, even in endosymbiotic organelles. Poly(A) specific ribonuclease (PARN) is distributed widely among eukaryotes and has been shown to regulate the poly(A) status of cytoplasmic mRNA in various organisms. Surprisingly, our recent study revealed that PARN also directly regulates poly (A) status of mitochondrial mRNA in Arabidopsis. In this addendum, we discuss whether this mitochondrial function of PARN is common in plants and why PARN has been assigned such a unique function.