Human OVGP1 enhances tyrosine phosphorylation of proteins in the fibrous sheath involving AKAP3 and increases sperm-zona binding

Abstract

Purpose To investigate if the recombinant human oviduct-specific glycoprotein (rHuOVGP1)–enhanced tyrosine-phosphorylated (pY) proteins are components of specific structure(s) of the sperm tail and if rHuOVGP1 binds to the oocyte and enhances sperm-egg binding. Methods Immunofluorescent staining and confocal microscopy were performed to examine the localization of pY proteins, outer dense fiber (ODF), and A-Kinase Associated Protein 3 (AKAP3) in human sperm during capacitation. Western blot and immunoprecipitation were employed to analyze protein levels of pY proteins and AKAP3. Immunofluorescent staining was performed to examine the binding of rHuOVGP1 to human oocytes. The effect of rHuOVGP1 on enhancing sperm-zona binding was examined using hemizona assay. Results pY proteins were detected mainly in the fibrous sheath (FS) surrounding the ODF with a relatively weak immunoreaction in the neck and mid-piece. Western blot analysis revealed co-migration of the pY 105 kDa protein with AKAP3, which was further confirmed by immunoprecipitation correlating immunofluorescent results of co-localization of pY proteins with AKAP3 in the sperm tail. rHuOVGP1 binds specifically to the zona pellucida (ZP) of human oocytes. Prior incubation of sperm and/or ZP with rHuOVGP1 increased sperm-egg binding. Conclusions The present study revealed that one of the major rHuOVGP1-enhanced pY proteins could be AKAP3 of the FS and that rHuOVGP1 is capable of binding to human ZP and its presence in the medium results in an increase in sperm-zona binding. Supplement of rHuOVGP1 in in vitro fertilization media could be beneficial for enhancement of the fertilizing ability of human sperm.

Absence of murine CFAP61 causes male infertility due to multiple morphological abnormalities of the flagella

“…KO males were completely sterile. phological defects and characterized by sperm flagella which are short, coiled, irregular, or even absent-has been associated with a variety of genes in humans and in mice (e.g., AKAP3, AKAP4, AK7, CCDC39, DNAH1, CFAP43, CFAP44, CFAP69, CFAP65, CFAP70, CFAP251, SPATA6, TE KT4, TSSK4, ODF2, ROPN1, FSIP2, TTC21A, and QRICH2) [3,7,[13][14][15][16][17][18][19][20][21][22][23][24][25]27,32,33]. The increasingly large number of such genes emphasizes the extensive genetic heterogeneity of MMAF, strongly suggest that more genes remain to be identified for MMAF.…”

“…Therefore, different mutant mouse models have been developed to study the genetic and molecular causes of sperm developmental defects, yielding deep understanding regarding spermatogenesis [12]. Previous studies in human and mutant mouse models have investigated and identified several genes associated with flagella abnormalities including AKAP3, AKAP4, AK7, CCDC39, DNAH1, CFAP43, CFAP44, CFAP69, CFAP65, CFAP70, CFAP251, SPATA6, TEKT4, TSSK4, ODF2, ROPN1, FSIP2, R2D2, TTC21A and QRICH2 [3,4,7,[13][14][15][16][17][18][19][20][21][22][23][24][25][26][27]. However, the etiology of several genetic factors responsible for MMAF is still elusive as genetic mutation accounts for 60% of MMAF defects, mirroring the strong genetic heterogeneity which can occur with MMAF [3].…”

Sperm Proteome after Interaction with Reproductive Fluids in Porcine: From the Ejaculation to the Fertilization Site

“…Our data also showed the presence of oviductin, which is also in accord to previous studies where oviductin recruitment on the sperm membrane has been shown [ 62 ]. This protein is known to be present in OF from different species [ 38 , 80 ], such as pig, bovine, hamster, and human, where its binding to the head sperm plasma membrane was shown to have an important role inducing sperm capacitation [ 81 , 82 ]. Moreover, oviductin is involved in tyrosine phosphorylation of sperm proteins during in vitro capacitation, confirming its role in sperm fertility [ 82 , 83 ].…”

“…This protein is known to be present in OF from different species [38,80], such as pig, bovine, hamster, and human, where its binding to the head sperm plasma membrane was shown to have an important role inducing sperm capacitation [81,82]. Moreover, oviductin is involved in tyrosine phosphorylation of sperm proteins during in vitro capacitation, confirming its role in sperm fertility [82,83]. Some of the proteins identified in spermatozoa incubated with OF or SP + OF belong to the heat shock proteins family, such as endoplasmin, heat shock cognate 71 kDa protein, 78 kDa glucose-regulated protein, and heat shock protein HSP 90-beta.…”

Superficial and profound considerations about sperm quality

“…Lastly, the study from Bichara et al [4] sheds new light on deeper aspects, such as the impact of sperm nuclear damage on ICSI outcomes. To better characterize this negative effect, the authors examined clinical pregnancy rates after ICSI according to several types of sperm DNA damage (sperm head vacuoles, chromatin condensation, DNA fragmentation, and aneuploidy) that were explored simultaneously in 132 couples with male factor or mixed infertility.…”