Proteins required for vacuolar function are targets of lysine polyphosphorylation in yeast

Abstract

Polyphosphates (polyP) are long chains of inorganic phosphates that can be attached to lysine residues of target proteins as a non-enzymatic post-translational modification. This modification, termed polyphosphorylation, may be particularly prevalent in bacterial and fungal species that synthesize and store large quantities of polyP. In this study, we applied a proven screening strategy to evaluate the polyphosphorylation status of over 200 candidate targets in the budding yeast S. cerevisiae. We report 8 new polyphosphorylated proteins that interact genetically and physically with a previously identified network of targets implicated in ribosome biogenesis. The expanded target network includes vacuolar proteins Prb1 and Apl5, whose modification with polyP suggests a model for feedback regulation of polyP synthesis, while raising additional questions regarding the location of polyphosphorylation in vivo.

Metabolic consequences of polyphosphate synthesis and imminent phosphate limitation

“…There is potential for this because polyP has a significant role for the storage of cations, such as for Zn 2+ , Ca 2+ , Mn 2+ and Mg 2+ (88–91), but also for cation uptake, as shown for Mg 2+ (92). Furthermore, polyP may affect cellular signaling, influencing the stress response (93–96). Here, it may even have direct impact, such as through polyphosphorylation of lysine residues, which modifies yeast topoisomerase 1 (Tpo1) and nuclear signal recognition factor 1 (Nsr1) (97, 98).…”

The maximum growth rate hypothesis is correct for eukaryotic photosynthetic organisms, but not cyanobacteria

“…Of particular interest is the role of lysine polyphosphorylation in ribosome biosynthesis in yeast and humans (Bentley‐DeSousa et al ., 2018; Lorenzo‐Orts et al ., 2020; McCarthy et al ., 2020). In yeast c .…”

“…Of particular interest is the role of lysine polyphosphorylation in ribosome biosynthesis in yeast and humans (Bentley-DeSousa et al, 2018;Lorenzo-Orts et al, 2020;McCarthy et al, 2020). In yeast c. 7% of proteins have one or more PASK-like motifs (stretches of 20 amino acids with up to at least 15 glutamate, aspartate and serine residues and at least one lysine residue), and the 17 known polyphosphorylated proteins are preferentially localized to the nucleolus.…”