Mendes, Tasha K.Novakovic, StevanRaymant, GretaBertram, Sonja E.Esmaillie, RezaNadarajan, SaravanapriahBreugelmans, BertHofmann, AndreasGasser, Robin B.Colaiacovo, MonicaBoag, Peter R.2015-03-022015Mendes, T. K., S. Novakovic, G. Raymant, S. E. Bertram, R. Esmaillie, S. Nadarajan, B. Breugelmans, et al. 2015. “Investigating the Role of RIO Protein Kinases in Caenorhabditis elegans.” PLoS ONE 10 (2): e0117444. doi:10.1371/journal.pone.0117444. http://dx.doi.org/10.1371/journal.pone.0117444.1932-6203http://nrs.harvard.edu/urn-3:HUL.InstRepos:14065494RIO protein kinases (RIOKs) are a relatively conserved family of enzymes implicated in cell cycle control and ribosomal RNA processing. Despite their functional importance, they remain a poorly understood group of kinases in multicellular organisms. Here, we show that the C. elegans genome contains one member of each of the three RIOK sub-families and that each of the genes coding for them has a unique tissue expression pattern. Our analysis showed that the gene encoding RIOK-1 (riok-1) was broadly and strongly expressed. Interestingly, the intestinal expression of riok-1 was dependent upon two putative binding sites for the oxidative and xenobiotic stress response transcription factor SKN-1. RNA interference (RNAi)-mediated knock down of riok-1 resulted in germline defects, including defects in germ line stem cell proliferation, oocyte maturation and the production of endomitotic oocytes. Taken together, our findings indicate new functions for RIOK-1 in post mitotic tissues and in reproduction.en-USJournal Article2015-03-0210.1371/journal.pone.0117444