Probable regulatory subunit of serine/threonine phosphatase let-92. Together with let-92 and constant regulatory subunit paa-1, positively regulates centriole duplication during early embryonic cell divisions by preventing the degradation of sas-5 and kinase zyg-1 (PubMed:21497766). In addition, during vulva development, may play a role with phosphatase let-92 and regulatory subunit paa-1 in the induction of vulva cell precursors by positively regulating let-60/Ras-MAP kinase signaling, probably by promoting lin-45 activation (PubMed:10521400, PubMed:14724126). In intestinal epithelial cells, may play a role in the late secretory pathway probably by regulating the exocyst, a protein complex involved in targeting secretory vesicles to the plasma membrane (PubMed:24192838). 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 (Probable). Interacts with let-92 (PubMed:21497766). RNAi-mediated knockdown causes severe embryonic lethality (PubMed:10521400). In mutants, during the first embryonic divisions, P1 cell initiates division prior to AB cell, spindles appear abnormal or collapse during anaphase and chromatin bridges and supernumerary centrosomes are often detected (PubMed:14724126). In addition, RNAi-mediated knockdown causes a partial defect in centriole duplication during the first embryonic divisions where 24% of spindles are monopolar and 47% have asymmetric spindles, a decrease in the spindle protein sas-5 levels and occasional bridging of chromatin with no obvious defects in cell cycle progression or mitotic exit (PubMed:21497766). The few surviving animals of RNAi-mediated knockdown lack a vulva resulting from defects in vulva cell induction, vulva precursor cell (VPC) generation and in vulval execution lineage, and are slightly uncoordinated (PubMed:10521400). In L4 larvae mutants, somatic mpk-1/ERK phosphorylation is also severely reduced (PubMed:14724126). In intestinal epithelial cells, RNAi-mediated knockdown causes an accumulation of SNARE proteins including snb-1, snap-29 and syx-4 (PubMed:24192838). RNAi-mediated knockdown at the L1 larval stage in the exocyst component exoc-8 (ok2523) mutant background results in lethality (PubMed:24192838). Belongs to the phosphatase 2A regulatory subunit B family.