Cellular and Molecular Life Sciences CMLS

, Volume 55, Issue 6, pp 944–960

Semenogelin I: a coagulum forming, multifunctional seminal vesicle protein

  • M. Robert
  • C. Gagnon

DOI: 10.1007/s000180050346

Cite this article as:
Robert, M. & Gagnon, C. CMLS, Cell. Mol. Life Sci. (1999) 55: 944. doi:10.1007/s000180050346


Human seminal plasma spontaneously coagulates after ejaculation. The major component of this coagulum is semenogelin I, a 52-kDa protein expressed exclusively in the seminal vesicles. Recently, a sperm motility inhibitor has been found to be identical to semenogelin I, suggesting that it may also be a physiological sperm motility inhibitor. The protein is rapidly cleaved after ejaculation by the chymotrypsin-like prostatic protease prostate-specific antigen, resulting in liquefaction of the semen coagulum and the progressive release of motile spermatozoa. Some of the cleavage products of Sg I may also have various biological functions. While the semenogelin I protein is unique to human and higher primates, it has recently been shown to belong to a gene family having a similar gene structure but encoding widely differing proteins. The recently elucidated characteristics of the semenogelin I gene as well as the biochemical and functional properties of the encoded protein are reviewed, and an attempt is made to integrate the various findings into a model for semen coagulation, sperm immobilization and potential other functions.

Key words. Seminal plasma; sperm motility inhibitor; prostate-specific antigen; seminal vesicle-specific antigen; inhibin-like peptides; REST gene; sperm hyaluronidase. 

Copyright information

© Birkhäuser Verlag Basel, 1999

Authors and Affiliations

  • M. Robert
    • 1
  • C. Gagnon
    • 2
  1. 1.Chugai Research Institute for Molecular Medicine, Inc., 153-2 Nagai, Niihari-mura, Ibaraki, 300-0041 (Japan)JP
  2. 2.Urology Research Laboratory, Rm H6.46, Royal Victoria Hospital, 687 Pine Avenue West, Montréal, Québec, H3A 1A1 (Canada), Fax +1 514 843 1457, e-mail: cgagnon@is.rvh.mcgill.caCA