A disintegrin and metalloprotease 3, or ADAM3, belongs to a family of peptidase proteins referred to as ADAMs. Many of these are solely found in spermatogenic cells, specifically in the anterior portion of capacitated spermatozoa heads. This membrane protein is critical for crucial steps in fertilization such as migration of sperm through the uterus to the oviduct as well as binding to the zona pellucida. Inactivation of ADAM3 is a cause of male infertility. [1]
Numerous studies have detailed that in ADAM3 null mice, the spermatozoa fail to migrate through the utero-tubal junction. Furthermore, knockout of the closely related ADAM1a gene in mice, an estrogen receptor not found in mature spermatozoa, causes loss of surface ADAM3 and decreased zona pellucida binding. Other studies have shown ADAM3-/- mouse spermatozoa fail to show sperm-sperm aggregation, although the significance of this is still unknown. ADAM3 has not yet been found in humans.
Acrosin is a digestive enzyme that acts as a protease. In humans, acrosin is encoded by the ACR gene. Acrosin is released from the acrosome of spermatozoa as a consequence of the acrosome reaction. It aids in the penetration of the Zona Pellucida.
ADAMs are a family of single-pass transmembrane and secreted metalloendopeptidases. All ADAMs are characterized by a particular domain organization featuring a pro-domain, a metalloprotease, a disintegrin, a cysteine-rich, an epidermal-growth factor like and a transmembrane domain, as well as a C-terminal cytoplasmic tail. Nonetheless, not all human ADAMs have a functional protease domain, which indicates that their biological function mainly depends on protein–protein interactions. Those ADAMs which are active proteases are classified as sheddases because they cut off or shed extracellular portions of transmembrane proteins. For example, ADAM10 can cut off part of the HER2 receptor, thereby activating it. ADAM genes are found in animals, choanoflagellates, fungi and some groups of green algae. Most green algae and all land plants likely lost ADAM proteins.
Zona pellucida sperm-binding protein 3, also known as zona pellucida glycoprotein 3 (Zp-3) or the sperm receptor, is a ZP module-containing protein that in humans is encoded by the ZP3 gene. ZP3 is the glycoprotein in the zona pellucida most important for inducting the acrosome reaction of sperm cells at the beginning of fertilization.
Disintegrin and metalloproteinase domain-containing protein 15 is an enzyme that in humans is encoded by the ADAM15 gene.
Immunocontraception is the use of an animal's immune system to prevent it from fertilizing offspring. Contraceptives of this type are not currently approved for human use.
Disintegrin and metalloproteinase domain-containing protein 9 is an enzyme that in humans is encoded by the ADAM9 gene.
Sperm surface protein Sp17 is a protein that in humans is encoded by the SPA17 gene.
Zona pellucida sperm-binding protein 2 is a protein that in humans is encoded by the ZP2 gene.
Outer dense fiber protein 1 is a protein that in humans is encoded by the ODF1 gene.
Zona pellucida sperm-binding protein 4, ZP-4 or avilesine, named after its discoverer Manuel Avilés Sánchez is a protein that in humans is encoded by the ZP4 gene.
Disintegrin and metalloproteinase domain-containing protein 2 or Beta-fertilin is an enzyme that in humans is encoded by the ADAM2 gene.
Sperm acrosome membrane-associated protein 3 is a protein that in humans is encoded by the SPACA3 gene. It may be involved in adhesion to the egg before the egg is fertilized.
Disintegrin and metalloproteinase domain-containing protein 28 is an enzyme that in humans is encoded by the ADAM28 gene.
Sperm protein associated with the nucleus on the X chromosome A is a protein that in humans is encoded by the SPANXA1 gene.
Disintegrin and metalloproteinase domain-containing protein 11 is an enzyme that in humans is encoded by the ADAM11 gene.
Eppin is a protein that in humans is encoded by the SPINLW1 gene.
Disintegrin and metalloproteinase domain-containing protein 18 is an enzyme that in humans is encoded by the ADAM18 gene.
Disintegrin and metalloproteinase domain-containing protein 7 is a protein that in humans is encoded by the ADAM7 gene. ADAM7 is an 85-kDa enzyme that is a member of the transmembrane ADAM protein family. Members of this family are membrane-anchored proteins structurally related to snake venom disintegrins, and have been implicated in a variety of biological processes involving cell-cell and cell-matrix interactions, including fertilization, muscle development, and neurogenesis. ADAM7 is important for the maturation of sperm cells in mammals. ADAM7 is also denoted as: ADAM_7, ADAM-7, EAPI, GP-83, and GP83.
Disintegrin and metalloproteinase domain-containing protein 20 is an enzyme that in humans is encoded by the ADAM20 gene. It is a membrane disintegrin-metalloprotease that belongs to the ADAM family. It is exclusively expressed in Testes and is similar to sperm cell-specific fertilins -alpha and -beta.
Geminin coiled-coil domain-containing protein 1 (GEMC1) is a Geminin family chromatin-binding protein encoded by the GMNC gene located on Chromosome 3 band 3q28. It is involved in the cell cycle, initiation of DNA replication, cilium assembly, and cell population proliferation. Reduced Generation of Multiple Motile Cilia (RGMC) is a rare ciliopathy characterized by hydrocephalus, the buildup of mucus in the airways, and reduced fertility that can be linked to defective multiple ciliated cell (MCC) differentiation, a process in which GEMC1, MCIDAS, and CCNO are crucial.