Monoclonal antibody that recognizes an epitope of the sperm equatorial region and specifically inhibits sperm-oolemma fusion but not binding

Noor, Mahanem Mat; Moore, H. D. M.

doi:10.1530/jrf.0.1150215

Cited by 16 publications

(11 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Several research groups have previously identified immunoreagents that react with equatorial segment proteins similar in size to ESP [8,10,11]. Noor and Moore [10] purified and injected hamster sperm heads into mice and raised monoclonal antibodies with strong affinity for spermatozoa.…”

Section: Esp: a Protein Concentrated In The Equatorial Segment Of Matmentioning

confidence: 99%

“…Noor and Moore [10] purified and injected hamster sperm heads into mice and raised monoclonal antibodies with strong affinity for spermatozoa. One of their monoclonal antibodies (M1) recognized the equatorial segment of hamster sperm, as revealed by immunofluorescence microscopy, and bound protein bands of 37.5 and 34 kDa on a Western blot.…”

Section: Esp: a Protein Concentrated In The Equatorial Segment Of Matmentioning

confidence: 99%

“…Here, we describe the coring and microsequencing of two protein spots that bound Con-A, leading to the cloning and characterization of a novel protein, equatorial segment protein (ESP; GenBank accession AF275321), that is localized to the equatorial segment of the human sperm early in development and defines a distinct equatorial segment subcompartment in the acrosomal vesicles of Golgi, cap, elongation, and maturation phase spermatids. Although other researchers have described acrosomal biogenesis in various species [8][9][10][11][12][13], the specification of a discrete equatorial segment domain segregating and persisting in the acrosomal vesicle during subsequent phases of acrosomal biogenesis has not been reported. We also propose a modified model for acrosomal morphogenesis.…”

Section: Introductionmentioning

confidence: 98%

See 2 more Smart Citations

Equatorial Segment Protein Defines a Discrete Acrosomal Subcompartment Persisting Throughout Acrosomal Biogenesis1

Wolkowicz

Shetty

Westbrook

et al. 2003

Biology of Reproduction

View full text Add to dashboard Cite

The equatorial segment of the acrosome underlies the domain of the sperm that fuses with the egg membrane during fertilization. Equatorial segment protein (ESP), a novel 349-amino acid concanavalin-A-binding protein encoded by a two-exon gene (SP-ESP) located on chromosome 15 at q22, has been localized to the equatorial segment of ejaculated human sperm. Light microscopic immunofluorescent observations revealed that during acrosome biogenesis ESP first appears in the nascent acrosomal vesicle in early round spermatids and subsequently segregates to the periphery of the expanding acrosomal vesicle, thereby defining a peripheral equatorial segment compartment within flattened acrosomal vesicles and in the acrosomes of early and late cap phase, elongating, and mature spermatids. Electron microscopic examination revealed that ESP segregates to an electron-lucent subdomain of the condensing acrosomal matrix in Golgi phase round spermatids and persists in a similar electron-lucent subdomain within cap phase spermatids. Subsequently, ESP was localized to electron-dense regions of the equatorial segment and the expanded equatorial bulb in elongating spermatids and mature sperm. ESP is the earliest known protein to be recognized as a marker for the specification of the equatorial segment, and it allows this region to be traced through all phases of acrosomal biogenesis. Based on these observations, we propose a new model of acrosome biogenesis in which the equatorial segment is defined as a discrete domain within the acrosomal vesicle as early as the Golgi phase of acrosome biogenesis.

show abstract

Section: Esp: a Protein Concentrated In The Equatorial Segment Of Matmentioning

confidence: 99%

Section: Esp: a Protein Concentrated In The Equatorial Segment Of Matmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 98%

See 1 more Smart Citation

Equatorial Segment Protein Defines a Discrete Acrosomal Subcompartment Persisting Throughout Acrosomal Biogenesis1

Wolkowicz

Shetty

Westbrook

et al. 2003

Biology of Reproduction

View full text Add to dashboard Cite

show abstract

“…Other proteins are also present in the sperm equatorial region, as shown by immunofluorescent and electron microscopy. Among them, the proteins recognized by antibodies M29 [22], M1 [23], G11, and G13 [24] appear after the acrosome reaction, whereas oscillin is revealed in permeabilized spermatozoa [25]. A set of fusion-related soluble N-ethylmalameide-sensitive factor attachment protein receptors (SNAREs) also occur in the equatorial region of a wide variety of mammalian spermatozoa [26].…”

Section: Introductionmentioning

confidence: 99%

Exposure of Sperm Head Equatorin after Acrosome Reaction and Its Fate after Fertilization in Mice1

Manandhar

Toshimori

2001

Biology of Reproduction

View full text Add to dashboard Cite

Equatorin is a sperm head equatorial protein, possibly involved in sperm-oocyte fusion (Toshimori et al., Biol Reprod 1998; 59:22-29). In the present work, we have shown that equatorin contained in the posterior acrosome is detectable only after spontaneous or induced acrosome reactions following fixation and permeabilization, but not in intact spermatozoa. The presence of protease inhibitors during sonication or ionophore treatments does not inhibit the exposure of the antigenic epitope. The zona-penetrated spermatozoa lying in the perivitelline space display equatorin, similar to those of the acrosome-reacted ones. After sperm-egg fusion during in vitro fertilization (IVF), the equatorin dissociates from the sperm head equatorial region and remains at the vicinity of the decondensing male pronuclei. During pronuclear apposition stage, it is pushed away from the pronuclei, possibly by the perinuclear microtubules. After first cleavage, equatorin is inherited by one of the proembryonic cells. The residual equatorin disappears after the second cleavage. Microinjected whole spermatozoa or sperm heads into the MII stage oocytes display equatorin similar to those of the perivitelline sperm. After activation, it dissociates from the sperm nuclei in a similar manner as during IVF. The mode of equatorin degeneration during fertilization is similar to those of the sperm tail components or mitochondria, but different from those of the membrane associated proteins.

show abstract

“…Molecules located in the equatorial segment include the mouse 38 -48 kDa complex protein, equatorin, which can inhibit the sperm-egg fusion process in vitro and in vivo (Yoshinaga et al, 2001a), and M1, a hamster 37.5 and 34.0 kDa protein (Noor and Moore, 1999). G11/M13, a guinea pig 34 kDa protein changes its conformation during the acrosome reaction (Allen and Green, 1995).…”

Section: Acrosomal Modifications Duringmentioning

confidence: 99%

Organization and modifications of sperm acrosomal molecules during spermatogenesis and epididymal maturation

Yoshinaga

Toshimori

2003

Microscopy Res & Technique

View full text Add to dashboard Cite

The mammalian acrosome is a highly specialized organelle overlying the anterior part of the sperm nucleus and contains a variety of proteins, including hydrolytic enzymes and matrix molecules. Functionally, the anterior acrosome is involved in the acrosome reaction or sperm-zona pellucida interaction, while the equatorial segment (posterior acrosome) is involved in sperm-egg fusion. The acrosome is formed during spermiogenesis, during which associated molecules are transported from the Golgi apparatus and organized. Many of the molecules thus arranged gradually become compartmentalized during sperm passage through the epididymis. Some of them are further modified during the fertilization process. The findings indicate that acrosomal molecules are not only restricted to a specific region (domain) of the acrosome but also undergo ongoing relocation in a stage-specific manner during sperm maturation in the testis and epididymis. Such maturation-associated modifications are considered essential for sperm molecules to reach the correct or final site before fertilization. This review focuses on the organization and modifications of the acrosomal molecules as well as their compartmentalization within the acrosome.

show abstract

Monoclonal antibody that recognizes an epitope of the sperm equatorial region and specifically inhibits sperm-oolemma fusion but not binding

Abstract: Balb/c mice were immunized with purified hamster sperm heads for induction of antisera and the production of monoclonal antibodies that recognize preferentially the equatorial segment. Twenty-six hybridoma clones secreted monoclonal antibodies with strong affinity for spermatozoa. The

Cited by 16 publications

References 15 publications

Equatorial Segment Protein Defines a Discrete Acrosomal Subcompartment Persisting Throughout Acrosomal Biogenesis1

Equatorial Segment Protein Defines a Discrete Acrosomal Subcompartment Persisting Throughout Acrosomal Biogenesis1

Exposure of Sperm Head Equatorin after Acrosome Reaction and Its Fate after Fertilization in Mice1

Organization and modifications of sperm acrosomal molecules during spermatogenesis and epididymal maturation

Contact Info

Product

Resources

About