Lack of tyrosylprotein sulfotransferase-2 activity results in altered sperm-egg interactions and loss of ADAM3 and ADAM6 in epididymal sperm

J Biol Chem. 2011 Apr 15;286(15):13060-70. doi: 10.1074/jbc.M110.175463. Epub 2011 Feb 21.

Abstract

Tyrosine O-sulfation is a post-translational modification catalyzed by two tyrosylprotein sulfotransferases (TPST-1 and TPST-2) in the trans-Golgi network. Tpst2-deficient mice have male infertility, sperm motility defects, and possible abnormalities in sperm-egg membrane interactions. Studies here show that compared with wild-type sperm, fewer Tpst2-null sperm bind to the egg membrane, but more of these bound sperm progress to membrane fusion. Similar outcomes were observed with wild-type sperm treated with the anti-sulfotyrosine antibody PSG2. The increased extent of sperm-egg fusion is not due to a failure of Tpst2-null sperm to trigger establishment of the egg membrane block to polyspermy. Anti-sulfotyrosine staining of sperm showed localization similar to that of IZUMO1, a sperm protein that is essential for gamete fusion, but we detected little to no tyrosine sulfation of IZUMO1 and found that IZUMO1 expression and localization were normal in Tpst2-null sperm. Turning to a discovery-driven approach, we used mass spectrometry to characterize sperm proteins that associated with PSG2. This identified ADAM6, a member of the A disintegrin and A metalloprotease (ADAM) family; members of this protein family are associated with multiple sperm functions. Subsequent studies revealed that Tpst2-null sperm lack ADAM6 and ADAM3. Loss of ADAM3 is strongly associated with male infertility and is observed in knockouts of male germ line-specific endoplasmic reticulum-resident chaperones, raising the possibility that TPST-2 may function in quality control in the secretory pathway. These data suggest that TPST-2-mediated tyrosine O-sulfation participates in regulating the sperm surface proteome or membrane order, ultimately affecting male fertility.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • ADAM Proteins / genetics
  • ADAM Proteins / metabolism*
  • Animals
  • Cell Membrane / genetics
  • Cell Membrane / metabolism
  • Epididymis / cytology
  • Epididymis / enzymology
  • Female
  • Gene Expression Regulation / physiology
  • Immunoglobulins / genetics
  • Immunoglobulins / metabolism
  • Infertility, Male / enzymology
  • Infertility, Male / genetics
  • Male
  • Membrane Fusion / physiology*
  • Membrane Glycoproteins / genetics
  • Membrane Glycoproteins / metabolism*
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism
  • Mice
  • Mice, Knockout
  • Protein Processing, Post-Translational / physiology*
  • Proteome / genetics
  • Proteome / metabolism
  • Sperm-Ovum Interactions / physiology*
  • Spermatozoa / cytology
  • Spermatozoa / enzymology*
  • Sulfotransferases / genetics
  • Sulfotransferases / metabolism*

Substances

  • Immunoglobulins
  • Izumo1 protein, mouse
  • Membrane Glycoproteins
  • Membrane Proteins
  • Proteome
  • Sulfotransferases
  • TPST2 protein, mouse
  • ADAM Proteins
  • Adam3 protein, mouse