This entry includes FKBP6 from mammals and protein shutdown (shu) from flies. FKBP6 is a testis-sperm specific protein that belongs to the immunophilins FKBP family known to be involved in meiosis, calcium homeostasis, clathrin-coated vesicles, and membrane fusions []. FKBP6 contains a PPIase FKBP-type domain and a TPR domain. However, it is inactive as an isomerase and associates with Hsp90 via its TPR domain []. Protein shutdown is essential for the formation of germline cysts during oogenesis []and is a component of the Drosophila piRNA biogenesis machinery [].
