Serine/threonine-protein kinase involved in a ribosome quality control that takes place when ribosomes have stalled, leading to 18S non-functional rRNA decay and degradation of the 40S ribosomal subunit (PubMed:39947182, PubMed:39947183, PubMed:40022732). Acts downstream of RNF10: specifically recognizes and binds RPS2/us5 and RPS3/us3 monoubiquitinated by RNF10, promoting degradation of the 40S ribosomal subunit in a kinase-dependent manner (PubMed:39947182, PubMed:39947183, PubMed:40022732). The RNF10-RIOK3 ribosome quality control takes place in response to ribosome subunit imbalance or downstream the EIF2AK4/GCN2-mediated integrated stress response (ISR) (PubMed:39947182, PubMed:39947183, PubMed:40022732). Also involved in regulation of type I interferon (IFN)-dependent immune response, possibly by acting as an adapter protein essential for the recruitment of TBK1 to IRF3 (PubMed:24807708). Phosphorylates IFIH1 on 'Ser-828' interfering with IFIH1 filament assembly on long dsRNA and resulting in attenuated IFIH1-signaling (PubMed:25865883). Can inhibit CASP10 isoform 7-mediated activation of the NF-kappa-B signaling pathway (PubMed:19557502). {ECO:0000269|PubMed:19557502, ECO:0000269|PubMed:24807708, ECO:0000269|PubMed:25865883, ECO:0000269|PubMed:39947182, ECO:0000269|PubMed:39947183, ECO:0000269|PubMed:40022732}. This is the function of Ensembl gene identifier ENSG00000101782 (RIOK3, RIO kinase 3).