RNA-binding protein, which regulates the expression of proteins required to control developmental timing of events during the L2 to L3 larval stage switch (PubMed:21471153). Binds to the 3'UTR of the transcript of the heterochronic protein lin-28 to post-transcriptionally negatively regulate its expression in certain tissue types in the later larval stages (PubMed:21471153). During larval development, controls the timing of seam cell division and terminal differentiation into adult alae (PubMed:21471153). In vitro, it can also bind to DNA through its first zinc finger (PubMed:21471153). May bind directly or indirectly to the promoter of the sex-determining factor xol-1 to activate its transcription (PubMed:23666922). Its activation of xol-1 transcription controls sex determination and X chromosome dosage compensation to promote male development (PubMed:23666922). Through the negative regulation of lin-28 transcript, it also has a role in the fox-1-sex-1-mediated determination of sexual fate (PubMed:21471153). Acts in the intestine to play a role in regulating adult lifespan (PubMed:21471153). In embryos, diffusely accumulates in the nucleus at the 20- to 30-cell stage, but nuclear localization decreases after the 200-cell stage (PubMed:23666922). Diffusely localized in the nucleus and cytoplasm during the L3 larval stage (PubMed:21471153). Expressed in seam cells, intestine cells, pharyngeal muscles and nerve ring neurons. In embryos, expressed in 20- to 30-cell stage and expression decreases after the 200-cell stage (PubMed:23666922). Expressed in seam cells, intestine cells, pharyngeal muscles and nerve ring neurons in L3 stage larvae and expression persists into adults (PubMed:21471153). The Zinc finger domains 1 and 5 bind single-stranded and double-stranded RNAs (PubMed:21471153). The Zinc finger domain 1 binds DNA in vitro (PubMed:21471153). RNAi mediated knockdown at early larval stages and in young adults results in an extended lifespan (PubMed:21471153). RNAi-mediated knockdown results in delayed developmental defects with an increased number of seam cells in young adults (PubMed:21471153). RNAi-mediated knockdown suppresses the embryonic lethality of hermaphrodites in the double fox-1 y303 and sex-1 y263 mutant background (PubMed:23666922).