Sequence-specific RNA-binding protein that acts as a post-transcriptional repressor by binding the 3'-UTR of mRNA targets. Binds to an RNA consensus sequence, the Pumilio Response Element (PRE), 5'-UGUANAUA-3', that is related to the Nanos Response Element (NRE) (, PubMed:21397187). Mediates post-transcriptional repression of transcripts via different mechanisms: acts via direct recruitment of the CCR4-POP2-NOT deadenylase leading to translational inhibition and mRNA degradation (PubMed:22955276). Also mediates deadenylation-independent repression by promoting accessibility of miRNAs (PubMed:18776931, PubMed:22345517). Acts as a post-transcriptional repressor of E2F3 mRNAs by binding to its 3'-UTR and facilitating miRNA regulation (PubMed:22345517). Plays a role in cytoplasmic sensing of viral infection (PubMed:25340845). Represses a program of genes necessary to maintain genomic stability such as key mitotic, DNA repair and DNA replication factors. Its ability to repress those target mRNAs is regulated by the lncRNA NORAD (non-coding RNA activated by DNA damage) which, due to its high abundance and multitude of PUMILIO binding sites, is able to sequester a significant fraction of PUM1 and PUM2 in the cytoplasm (PubMed:26724866). May regulate DCUN1D3 mRNA levels (PubMed:25349211). May support proliferation and self-renewal of stem cells. Binds specifically to miRNA MIR199A precursor, with PUM1, regulates miRNA MIR199A expression at a postranscriptional level (PubMed:28431233). Homodimer; homodimerizes in vitro. Interacts with DAZ1, DAZL and NANOS1 via its pumilio repeats. Interacts with NANOS3 (By similarity). Interacts with SNAPIN. Recruits the CCR4-POP2-NOT deadenylase leading to translational inhibition and mRNA degradation. Interacts with DDX20. In case of viral infection, interacts with DHX58 (PubMed:25340845). Interacts with TRIM71 (via NHL repeats) in an RNA-dependent manner (PubMed:23125361). The cytoplasmic granules are stress granules which are a dense aggregation in the cytosol composed of proteins and RNAs that appear when the cell is under stress. Colocalizes with NANOS3 in the stress granules. Colocalizes with NANOS1 and SNAPIN in the perinuclear region of germ cells. Expressed in male germ cells of adult testis (at protein level). Highly expressed in testis and ovary. Predominantly expressed in stem cells and germ cells. Expressed at lower level in brain, heart, kidney, liver, muscle, placenta, intestine and stomach Expressed in cerebellum, corpus callosum, caudate nucleus, hippocampus, medulla oblongata and putamen. Expressed in all fetal tissues tested. Down-regulated in keratinocytes upon UVB irradiation. The pumilio repeats mediate the association with RNA by packing together to form a right-handed superhelix that approximates a half donut. RNA-binding occurs on the concave side of the surface (PubMed:21397187). PUM2 is composed of 8 pumilio repeats of 36 residues; each repeat binds a single nucleotide in its RNA target. Residues at positions 12 and 16 of the pumilio repeat bind each RNA base via hydrogen bonding or van der Waals contacts with the Watson-Crick edge, while the amino acid at position 13 makes a stacking interaction. The recognition of RNA by pumilio repeats is base specific: cysteine and glutamine at position 12 and 16, respectively, bind adenine; asparagine and glutamine bind uracil; and serine and glutamate bind guanine.