Protein phosphatase which plays an essential role in early embryonic cell division (PubMed:20392746, PubMed:17218259, PubMed:21497766). Probably together with constant regulatory subunit paa-1 and regulatory subunit sur-6, positively regulates centriole duplication by preventing the degradation of sas-5 and kinase zyg-1 (PubMed:21497766). In addition, plays a role in the recruitment of sas-6 and maybe sas-5 to centrioles and may dephosphorylate sas-5 and zyg-1 negative regulator szy-20 (PubMed:21497766). During vulva development, may play a role with regulatory subunits paa-1 and sur-6 in the induction of vulva cell precursors by positively regulating let-60/Ras-MAP kinase signaling, probably by promoting lin-45 activation (PubMed:10521400). In association with regulatory subunit rsa-1 and probably paa-1, regulates microtubule outgrowth from centrosomes and mitotic spindle assembly ensuring the stability of kinetochore microtubules (PubMed:17218259). Plays a negative role in axon guidance probably by dephosphorylating unc-51, unc-14 and vab-8 (PubMed:20392746). H2O + O-phospho-L-seryl-[protein] = L-seryl-[protein] + phosphate H2O + O-phospho-L-threonyl-[protein] = L-threonyl-[protein] + phosphate Binds 2 manganese ions per subunit. Part of a complex consisting of a common heterodimeric core enzyme, composed of catalytic subunit let-92 and constant regulatory subunit paa-1, that associates with a variety of regulatory subunits which confer distinct properties to the holoenzyme (PubMed:17218259). Interacts with szy-20 and regulatory subunit sur-6 (PubMed:21497766). Interacts with regulatory subunit rsa-1 (PubMed:17218259). May interact with sas-5 (PubMed:21497766). Interacts with unc-51 and unc-14 (PubMed:20392746). Localizes to the margins of VD neuron growth cones and to small transport vesicles (PubMed:20392746). During mitosis, localizes around chromatin after the nuclear envelope breakdown (PubMed:17218259). Ubiquitously expressed. RNAi-mediated knockdown causes severe embryonic lethality (PubMed:10521400). Causes a failure to duplicate centrioles resulting in the formation of monopolar spindles at the 2-cell embryonic stage, a failure to align chromosomes at the metaphase plate, delayed cell cycle progression and defects in mitotic exit including failure to reform nuclei and decondense chromatin (PubMed:17218259, PubMed:21497766). Also causes a reduction in centrosomal microtubules (PubMed:17218259). In addition, recruitment of sas-6 to centriole is impaired and sas-5 and zyg-1 protein levels are reduced (PubMed:21497766). Few of the surviving animals show occasional defects in vulva induction (PubMed:10521400). Partially suppresses multivulva formation in a let-60 n1046 mutant background (PubMed:10521400). Belongs to the PPP phosphatase family. PP-1 subfamily.