Proteomics of post-translational modifications of mammalian spermatozoa.

It is hard to fathom that one of the most highly differentiated cells in the body, the spermatozoon, spends over half of its developmental life without the capacity for nuclear protein biosynthesis. This is even more incredible when considering that protein synthesis is switched off long before the sperm is mature. As such, in order to obtain full functionality, spermatozoa rely on post-translational modifications (PTM) of existing proteins. Many PTM have been shown to play a role in the development of a sperm cell. These include phosphorylation and glycosylation events that occur both in the epididymis and during capacitation. In addition, several other PTM such as disulfide cross-linking, ubiquitination, acetylation and methylation all play a role to both develop and enable a spermatozoon to achieve its final destiny.