Pumilio 1 (also known as PUM1 or FBF-1) is a highly conserved RNA-binding protein that is essential for embryonic development and postnatal growth in many animals. Pumilio 1 was first identified in Drosophila melanogaster, where it is required for germline stem cell self-renewal and maintenance of genomic integrity during spermatogenesis. Pumilio 1 has also been implicated in regulating cellular senescence, DNA repair, and cancer progression.
In mammals, Pumilio 1 is widely expressed in tissues including the brain, heart, kidney, liver, pancreas, skeletal muscle, and testis. In the brain, Pumilio 1 is enriched in neurons of the hippocampus and cortex. Functionally, Pumilio 1 binds to mRNAs encoding proteins involved in cell cycle control, cell death/survival signaling pathways, and cytoskeletal organization. For example, Pumilio 1 regulates expression of the tumor suppressor p53 by binding to its mRNA and promoting its translation into protein. Additionally, Pumilio 1 has been shown to be involved in neurite outgrowth and neuronal survival following cerebral ischemia (stroke).
Recent studies have revealed that alterations in Pumilio 1 levels or function contribute to several human diseases. Mutations in the gene encoding PUM1 are associated with autosomal recessive intellectual disability and microcephaly (small head size). In addition, decreased expression of PUM1 has been observed in various cancers including ovarian cancer