RNA-binding protein that plays an essential role in spermatogenesis. May act by binding to the 3'-UTR of mRNAs and regulating their translation. Promotes germ-cell progression to meiosis and formation of haploid germ cells. Forms a heterodimer with BOLL and DAZL. Interacts with PUM2, DAZAP1, DAZAP2, DZIP1 and DZIP3. Predominantly cytoplasmic. Nuclear at some stages of spermatozoide development. Localizes both to the nuclei and cytoplasm of spermatozoide differentiation. Nuclear in fetal gonocytes and in spermatogonial nuclei. It then relocates to the cytoplasm during male meiosis. Testis-specific. Expression restricted to premeiotic germ cells, particularly in spermatogonia (at protein level). The DAZ domains are essential and mediate the interaction with DAZAP1 and DAZAP2. The number as well as the precise structure of the DAZ proteins probably differs within the population. The disease may be caused by variants affecting the gene represented in this entry. AZFc deletions in the Yq11.23 region including the DAZ genes are the most common known genetic cause of human male infertility. DAZ genes are prone to deletions but also to duplications. In a population of infertile men, DAZ genes deletions are associated with oligozoospermia but an increased number of DAZ genes is not a significant risk factor for spermatogenic failure. The DAZ proteins (DAZ, DAZ2, DAZ4 and DAZ4) are all encoded by a strongly repeated region of the Y chromosome, in two clusters each comprising an inverted pair of DAZ genes. They are very similar, which gives their indidual characterization difficult. Thus, most experiments do not discriminate between the different members. One can therefore suppose that reported interactions with a DAZ protein involve all the 4 proteins. Belongs to the RRM DAZ family.