Distribution, crypticity, stability, and localization of α‐L‐fucosidase of mouse cauda epididymal sperm

Abstract

Sperm-associated and semen-specific isoforms of α-L-fucosidase are thought to function in fertilization in numerous organisms. Here, we report the localization, distribution, crypticity, and stability of this enzyme in mouse cauda epididymal sperm and cauda fluid. Western analysis revealed that the sperm-associated α-L-fucosidase is present as two isoforms (Mr ∼49 and 56 kDa), whereas the cauda fluid α-L-fucosidase shows a single band at 50 kDa. α-L-Fucosidase activity was detected using the fluorogenic substrate 4-MU-FUC. Of the total α-L-fucosidase activity recovered in the cauda epididymal contents, 74% was found in the cell-free cauda fluid and about 7% was found in sperm cells. During capacitation or permeabilization, cryptic intracellular stores of soluble enzyme were released to the supernatant, while leaving bound enzyme concentrated within the small volume of sperm. Moreover, membrane-associated enzyme activity was still detectable in acrosome-reacted cells. Immunofluorescence studies support the presence of α-L-fucosidase (originally localizing at the acrosomal area) at the equatorial segment after the acrosome reaction. α-L-Fucosidase activity of both cauda fluid and sperm at 37°C, 5% CO(2) was relatively stable and detectable up to 72 hr. The stability and appearance of mouse sperm-associated α-L-fucosidase in the equatorial segment after the acrosome reaction suggest that α-L-fucosidase may be involved in sperm-egg interaction.

Oviduct binding ability of porcine spermatozoa develops in the epididymis and can be advanced by incubation with caudal fluid

“…These include different secretory proteins either native to caudal fluid or transported from proximal regions and accumulated in this fluid [12,[16][17][18], enzymes [19], Ca 2+ concentrations and signalling mechanisms [20], sperm association or formation [21], and chemical characteristics of the fluid itself [22]. Given the above factors and the amount of time that spermatozoa spend in the cauda prior to ejaculation, it is logical to assume that the cauda and caudal fluid may play a significant role in developing the ability of spermatozoa to bind to oviduct epithelium.…”

Acrosome Reaction as a Preparation for Gamete Fusion

“…In humans, α-L-fucosidase is represented in the general membrane system of ejaculated spermatozoa but becomes enriched within the ES during capacitation and AR (Venditti et al 2007). In mice, enzyme activity assays and immunofluorescence studies support the original localization of α-L-fucosidase in the acrosomal area and its redistribution to the ES after the AR (Phopin et al 2012), suggesting its role in recognition of the egg plasma membrane. Although some differences have been reported according to the species studied, different lines of evidence support roles for α-L-fucosidase in fertilization.…”

“…Unlike the isoforms present in lysosomes and in seminal plasma, sperm α-L-fucosidase is not soluble, but rather it becomes associated with the plasma membrane of the cells presumably during spermatogenesis (Avilés et al 1996;Alhadeff et al 1999;Venditti et al 2007;Phopin et al 2012). In humans, α-L-fucosidase is represented in the general membrane system of ejaculated spermatozoa but becomes enriched within the ES during capacitation and AR (Venditti et al 2007).…”

“…α-L-fucosidase, a lysosomal enzyme ubiquitously expressed, has been found in spermatozoa from chimpanzees (Srivastava et al 1981), bull (Jauhiainen and Vanha-Perttula 1986), rat (Hancock et al 1993), human (Alhadeff et al 1999), boar (Park et al 2002), hamster (Venditti et al 2010), and mouse (Phopin et al 2012). Unlike the isoforms present in lysosomes and in seminal plasma, sperm α-L-fucosidase is not soluble, but rather it becomes associated with the plasma membrane of the cells presumably during spermatogenesis (Avilés et al 1996;Alhadeff et al 1999;Venditti et al 2007;Phopin et al 2012).…”

Drosophila sperm surface alpha-l-fucosidase interacts with the egg coats through its core fucose residues

“…In particular, experimental evidence suggest that sperm surface glycosidases could act in a non-catalytic or lectinlike manner, recognizing complementary sugar moieties in the egg envelope (Miranda et al, 2000;Martinez et al, 2000;Perotti et al, 2001;Miller et al, 2002;Intra et al, 2006;Zitta et al, 2006;Hedrick, 2008;Honegger and Koyanagi, 2008;Intra et al, 2011). Examples of glycosidases on the sperm plasma membrane include mannosidases and fucosidases in mammalian sperm (Tulsiani et al, 1989(Tulsiani et al, , 1990Venditti et al, 2010;Phopin et al, 2012Phopin et al, , 2013, fucosidases and N-acetylglucosaminidases in tunicates (Hoshi et al, 1983(Hoshi et al, , 1985(Hoshi et al, , 1994Hoshi, 1986;Godknecht and Honegger, 1991;Matsumoto et al, 2002;Downey and Lambert, 1994), and mannosidases, fucosidases and N-acetylglucosaminidases in flies (Cattaneo et al, 1997(Cattaneo et al, , 2002Pasini et al, 1999;Perotti et al, 2001;Intra et al, 2006Intra et al, , 2009Intra et al, , 2011. In insects, the mechanisms of spermeegg interactions are poorly understood, and spermeegg interactions have been studied in only two Dipteran species.…”