Sumo1-ylation of human spermatozoa and its relationship with semen quality

Int J Androl. 2011 Dec;34(6 Pt 1):581-93. doi: 10.1111/j.1365-2605.2010.01118.x. Epub 2010 Oct 6.

Abstract

Sumoylation is a post-translational modification involved in the regulation of several cell functions. Recent studies suggest its involvement in spermatogenesis, but occurrence and function of SUMO (small ubiquitin-like modifier) in mature spermatozoa remain unknown. We report the occurrence of several SUMO1-conjugated proteins, in a range of 20-85 kDa, in ejaculated spermatozoa. By cytofluorimetric analysis, we evaluated the percentage of SUMO1-positive spermatozoa in 58 subjects undergoing semen analysis in our laboratory and correlated the obtained values with semen parameters. We found that the percentage of SUMO1-positive spermatozoa was inversely correlated with total (r = -0.35, p < 0.01) and progressive motility (r = -0.29, p < 0.05). Such correlations become stricter when only asthenospermic subjects were included in the analysis (r = -0.58, p = 0.01 for progressive motility, n = 17) and were lost in non-asthenospermic subjects. By immunofluorescence and immunoconfocal fluorescence, we demonstrated that SUMO1 is mainly located in the nucleus and, occasionally, in the midpiece of spermatozoa. Immunoelectron microscopy as well as a long permeabilization protocol demonstrated a massive localization of SUMO-1 in the nucleus. By using a fluorescent probe to distinguish dead/live cells, we show that SUMO1 is mainly present in live spermatozoa. In conclusion, sumoylation of human spermatozoa may be involved in the regulation of motility.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blotting, Western
  • Fluorescent Antibody Technique
  • Humans
  • Male
  • Microscopy, Confocal
  • Microscopy, Immunoelectron
  • SUMO-1 Protein / metabolism*
  • Semen / metabolism*
  • Spermatozoa / metabolism*

Substances

  • SUMO-1 Protein