Male fertility in Mus musculus requires the activity of TRYX5 in sperm migration into the oviduct

Abstract

Nowadays, abnormal loss of serine proteases appears very frequently in male patients with unexplained sterility. In fact, many testis-specific serine proteases, the largest family among the four protease families implicated in murine spermatogenesis, are indispensable for reproduction. In the present study, we demonstrate that the previously uncharacterized testis-specific serine protease TRYX5 (1700074P13Rik) is required for male fertility in mice. Tryx5 −/− male mice are sterile, yet they have normal spermatogenesis and normal sperm parameters. In vivo fertilization experiments showed that the fertilization rate of Tryx5 −/− sperm was almost zero. Sperm counting and analysis of paraffin sections of oviducts revealed that Tryx5 −/− sperm were unable to migrate into the oviduct, which is likely the cause of the observed infertility of the Tryx5 −/− male mice. Importantly, we also found that there was almost no mature ADAM3 present in Tryx5 −/− sperm and almost no ADAM3 precursor in Tryx5 −/− elongated spermatids of S13-16 stage, even though testes of Tryx5 −/− and wild type mice had the same amount of the total precursor ADAM3. Collectively, our results demonstrate that Tryx5 is essential for male fertility in mice and suggest that TRYX5 functions in the stability or localization of ADAM3 precursor in elongated spermatids S13-16 stage, thereby regulating the ability of sperm to migrate from the uterus into the ampulla of the oviduct, the site of fertilization. K E Y W O R D Sknockout mouse, male infertility, sperm migration, Tryx5

Dissecting the PRSS37 interactome and potential mechanisms leading to ADAM3 loss in PRSS37-null sperm

“…Recent research suggested that serine protease TRYX5 may participate in the post-translational modification (PTM) of ADAM3 through an indirect way in the Golgi, and loss of TRYX5 may bring precursor ADAM3 into an unstable state and disappear in elongated spermatid of S13-16 stages owing to the lack of PTM (Zhang et al, 2020). In addition to testis-specific factors, a ubiquitously expressed protein, TPST2 ( protein-tyrosine sulfotransferase 2), is also related to ADAM3 quality control occurring past the ER, precisely in the ER-Golgi intermediate compartment and in the Golgi (Marcello et al, 2011).…”

“…Our previous studies have shown that sperm from mice deficient for the serine protease PRSS37 or PRSS55 failed to migrate from the uterus into the oviduct and impaired sperm-egg binding, and was accompanied by the disappearance of mature ADAM3 on the sperm surface (Shang et al, 2018;Shen et al, 2013). Most recently, mice deficient for a trypsin-like serine protease, TRYX5, also displayed a similar phenotype as that of Prss37 −/− and Prss55 −/− mice (Zhang et al, 2020). However, it is still unclear how these serine proteases mediate ADAM3 maturation, contributing to male fertility.…”

“…This was supported by the fact that ADAM3 binds to zona pellucida 3 (ZP3) protein (Kim et al, 2005). Second, ADAM3 is absent or abnormally located in the mature sperm of 19 gene-and two gene cluster-deficient mouse lines, including Clgn, Calr3, Pdilt, Adam1a, Adam2, Adam6, Prss37, Prss55, Tryx5 (also known as Prss59), Tex101, t-Ace, Tpst2, Rnase10, Pmis2, Lypd4, Cmtm2a/ 2b, Nell2, Ros1, Ovch2, Cst cluster and the Pate cluster (Fujihara et al, 2019(Fujihara et al, , 2018bKiyozumi et al, 2020;Wang et al, 2020;Xiong et al, 2019;Zhang et al, 2020). All of them share similar male infertility phenotypes as those shown by ADAM3 deficiency.…”

Proteolysis in Reproduction: Lessons From Gene-Modified Organism Studies

“…A group of genes encoding proteases, enzymatically inactive pseudoproteases, and protease inhibitors is apparently associated with the same physiological function, i.e., maturation of sperm conferring abilities to migrate into female oviduct and bind with zona pellucida. Ablation of Tmprss12 ( 66 ), Prss55 ( 67 , 68 ), Tryx5 ( 69 ), Prss37 ( 70 ), Ace ( 71 ), Adam1a ( 72 ), Adam2 ( 73 ), Adam3 ( 74 , 75 ), and Adam6 ( 76 ) results in deficient sperm migration into the oviduct and binding to the zona pellucida of eggs. Among them, Adam1a , Adam2 , Adam3 , Adam6 , and Prss37 encode catalytically inactive pseudoproteases.…”

“…PRSS37 supports ADAM3 precursor translocation to the sperm cell surface by collaborating with PDILT, a testis-specific protein disulfide isomerase indispensable for ADAM3 surface expression ( 197 , 198 ). TMPRSS12, PRSS55, and TRYX5, all of which are serine proteases and retain catalytic triad residues, are necessary for the production or stable localization of processed ADAM3 on the cell surface of epididymal spermatozoa ( 66 – 69 ), although it remains uncertain whether these proteases directly cleave ADAM3.…”