Heat Shock 40kDa Protein 4 (HSPF4)

DNAJA1 is most identical to YDJ1, which may be involved in the transport of certain proteins into the mitochondria and endoplasmic reticulum.Transplantation experiments with fluorescence-tagged spermatogonia into Dja1- mice revealed a primary defect of Sertoli cells in maintaining spermiogenesis at steps 8 and 9.

In Sertoli cells of Dja1- mice, the androgen receptor markedly accumulated with enhanced transcription of several androgen-responsive genes, including Pem (MUC1) and testis-derived transcript (TES). Disruption of Sertoli-germ cell adherens junctions was also evident in Dja1- mice. Experiments with Dja1- fibroblasts and primary Sertoli cells indicated aberrant androgen receptor signaling.