Regulatory subunit of protein phosphatase 6 (PP6) (Probable). In complex with pph-6, promotes actomyosin contractility during cytokinesis by regulating the organization of cortical non-muscle myosin II nmy-2 and thus contributing to correct spindle positioning (PubMed:20040490). Also required for the proper generation of pulling forces on spindle poles during anaphase by regulating the cortical localization of gpr-1, gpr-2 and lin-5 (PubMed:20040490). Negatively regulates kinase air-1 localization at the cell cortex (PubMed:27335426). Forms a complex composed of catalytic subunit pph-6 and regulatory subunit saps-1; the interaction increases pph-6 and saps-1 protein stability (PubMed:20040490). Interacts with kinase air-1 (PubMed:27335426). In embryos, localizes mainly to the cytoplasm and to a lesser extent with microtubule asters. Expressed in embryos. RNAi-mediated knockdown causes severe reduction in cortical contractions and lack of pseudocleavage furrow formation in the 1-cell embryo (PubMed:20040490, PubMed:27335426). Positioning of the spindle is abnormal due to reduced pulling forces that prevent oscillatory movements of the posterior spindle pole during anaphase (PubMed:20040490, PubMed:27335426). Belongs to the SAPS family.