title: Lack of tyrosylprotein sulfotransferase-2 activity results in altered sperm-egg interactions and loss of ADAM3 and ADAM6 in epididymal sperm.
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.
authors.affiliation: Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland 21205, USA.
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Marcello
authors.forename: Weitao
authors.initials: W
authors.lastname: Jia
authors.forename: Julie A
authors.initials: JA
authors.lastname: Leary
authors.forename: Kevin L
authors.initials: KL
authors.lastname: Moore
authors.forename: Janice P
authors.initials: JP
authors.lastname: Evans
mesh_terms: D051722:ADAM Proteins / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D002462:Cell Membrane / Q000235:genetics / Q000378:metabolism; D004822:Epididymis / Q000166:cytology / Q000201:enzymology; D005260:Female; D005786:Gene Expression Regulation / Q000502:physiology; D007136:Immunoglobulins / Q000235:genetics / Q000378:metabolism; D007248:Infertility, Male / Q000201:enzymology / Q000235:genetics; D008297:Male; D008561:Membrane Fusion / Q000502:physiology*; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D011499:Protein Processing, Post-Translational / Q000502:physiology*; D020543:Proteome / Q000235:genetics / Q000378:metabolism; D013084:Sperm-Ovum Interactions / Q000502:physiology*; D013094:Spermatozoa / Q000166:cytology / Q000201:enzymology*; D015238:Sulfotransferases / Q000235:genetics / Q000378:metabolism*
chemical_list: D007136:Immunoglobulins; C498177:Izumo1 protein, mouse; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D020543:Proteome; D015238:Sulfotransferases; C529648:TPST2 protein, mouse; D051722:ADAM Proteins; C485429:Adam3 protein, mouse