Proteome profiling of phosphatidylinositol-5-phosphate 4-kinase type 2A and 2B knockdown cells identify modifications in key regulators involved in cell homeostasis and genome integrity

Abstract

Phosphatidylinositol-5-phosphate 4-kinases (PIP4K) are multiple cellular process regulatory lipid kinases. PIP4K2A and PIP4K2B are overexpressed in cancer. The recently reported kinase-independent role of PIP4K2A and PIP4K2B underscore the complexity of the underlying molecular changes and mechanisms involved. Here, we show proteome analysis of PIP4K2A, PIP4K2B and PIP4K2A/2B co-depleted osteosarcoma cells to reflect changes in protein expression and their post-translational modifications. PIP4K2A depletion mainly affects ribosome assembly, translation and cell proliferation. Proteins of the apoptotic process, DNA repair, and cell division are mainly affected in PIP4K2B knockdown cells. PIP4K2A/2B co-depletion affects proteins regulating vesicle transport, cell motility, RNA splicing, and cell division. PIP4K depletion also affects post-translational modifications (phosphorylation, acetylation) of proteins involved mainly in nucleosome organization, mRNA splicing, and DNA replication. In addition, we observed PIP4K2A and PIP4K2B overexpression in cells harbouring K-Ras G12V or G12D mutations. Collectively, our results show that single or co-depletion of the PIP4K isoforms regulate proteins participating in metabolism and maintenance of genome integrity. Given that PIP4K2A and PIP4K2B alter proteins related to genome instability and their role in cancer, these enzymes could be promising therapeutic targets for cells experiencing genotoxic stress conditions.

Funding

Council of Scientific and Industrial Research, India