YjeF N-Terminal Domain Containing Protein 3 (YJEFN3)

YjeF_N domain containing proteins beside the apolipoprotein A-I interacting protein, identified two other genes designated hYjeF_N2-15q23 and hYjeF_N3-19p13.11 comprising the human YjeF_N family. Immunohistochemistry of human testes and ovaries showed an expression of hYjeF_N3-19p13.11 only in Leydig cells and theca cells, respectively, indicating a role in steroid hormone metabolism. Interestingly, the protein was also strongly expressed in Leydig cell tumors and in thecofibromas. The identification of hYjeF_N2-15q23 in theca cells and granulosa cells in ovaries, in human spermatids of meiotic division part II and the apical membrane of Sertoli cells in testes suggest similar functions in oogenesis and sperm maturation which is strengthened by the identification of the spermatogenesis regulator HMGA1 as a conserved transcription factor.