Function of human epididymal proteins in sperm maturation.
Human post-testicular proteins were cloned by subtractive screening of epididymal cDNA libraries, employing testis as the primary negative control. This method identified six human epididymal cDNAs, named HE1-HE6, which are derived from abundant epididymal mRNAs. With the exception of HE5, which turned out to be identical to the lymphocyte surface antigen CD52, they represented completely novel human gene products. To date, there is little information on their function and the mechanism of their deposition on the sperm surface. Unlike the sperm coating antigens, CD52 binds firmly to the sperm membrane via its GPI anchor during epididymal passage. Its synthesis is carefully regulated by the epididymal epithelium. From the results of both in vivo and in vitro studies it was concluded that androgen and temperature are principal factors synergistically modulating epididymal CD52 expression. The human counterparts of two well-known major rodent epididymal proteins, secretory epididymal glutathione peroxidase (sGPX) and acidic epididymal glycoprotein (AEG = Protein DE), were not cloned by the subtractive screening approach, but by RT-PCR amplification.
Kirchhoff
C
C
IHF Institute for Hormone and Fertility Research, University of Hamburg, Germany.
Osterhoff
C
C
Pera
I
I
Schröter
S
S
D015703:Antigens, CD / Q000378:metabolism; D000951:Antigens, Neoplasm; D000954:Antigens, Surface / Q000378:metabolism; D000074301:CD52 Antigen; D002352:Carrier Proteins; D002784:Cholesterol / Q000378:metabolism; D003001:Cloning, Molecular; D030501:Epididymal Secretory Proteins; D004822:Epididymis / Q000166:cytology / Q000502:physiology*; D005979:Glutathione Peroxidase / Q000378:metabolism; D006020:Glycopeptides / Q000378:metabolism; D006023:Glycoproteins / Q000378:metabolism; D006801:Humans; D008297:Male; D008667:Metalloproteins / Q000378:metabolism; D011506:Proteins / Q000235:genetics / Q000502:physiology*; D011956:Receptors, Cell Surface / Q000378:metabolism; D043562:Receptors, G-Protein-Coupled; D011994:Recombinant Proteins; D013075:Sperm Capacitation; D013079:Sperm Maturation / Q000502:physiology*; D013735:Testicular Hormones / Q000378:metabolism; D033921:Vesicular Transport Proteins; D023083:beta-Defensins
C105986:ADGRG2 protein, human; D015703:Antigens, CD; D000951:Antigens, Neoplasm; D000954:Antigens, Surface; D000074301:CD52 Antigen; C000613862:CD52 protein, human; D002352:Carrier Proteins; C426184:DEFB126 protein, human; D030501:Epididymal Secretory Proteins; D006020:Glycopeptides; D006023:Glycoproteins; D008667:Metalloproteins; C104585:NPC2 protein, human; D011506:Proteins; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled; D011994:Recombinant Proteins; C087044:SPAG11A protein, human; D013735:Testicular Hormones; D033921:Vesicular Transport Proteins; D023083:beta-Defensins; D002784:Cholesterol; D005979:Glutathione Peroxidase