Human pentatricopeptide proteins: only a few and what do they do?

Abstract

Pentatricopeptide repeat (PPR) proteins constitute a large family of RNA-binding proteins that contain a canonical 35 residue repeat motif. Originally identified in Arabidopsis thaliana, family members are found in protists, fungi, and metazoan but are by far most abundant in plant organelles. Seven examples have been identified in human mitochondria and roles have been tentatively ascribed to each. In this review, we briefly outline each of these PPR proteins and discuss the role each is believed to play in facilitating mitochondrial gene expression.

Keywords: Pentatricopeptide; RNA binding; human; mitochondria; post-transcriptional gene expression; translation.

Figure 1. Cartoon depicting LRPPRC, a subset of its interacting partners, and processes in which it is involved. LRPPRC has a number of interactions that facilitate mitochondrial gene expression. It has also been reported to be involved in other cellular processes. The size of the arrow between LRPPRC and the surrounding balloons, together with the intensity of the balloon color, is an indicator of the amount of literature supporting these connections.