High impact information on Adam3

• Moreover, the appearance of ADAM3 on the sperm surface was dependent on the formation of a fertilin protein complex between ADAM1a and ADAM2 (fertilin beta) in testicular germ cells, although no direct interaction between the fertilin complex and ADAM3 was found [1].
• Among testis (sperm)-specific proteins examined, only the level of ADAM3 (cyritestin) was strongly reduced in ADAM1a-deficient mouse sperm [1].
• These results suggest that ADAM1a/ADAM2 fertilin may be implicated in the selective transport of specific sperm proteins including ADAM3 from the endoplasmic reticulum of testicular germ cells onto the cell surface [1].
• ADAM 3 is a sperm surface glycoprotein that has been implicated in sperm-egg adhesion [2].
• This paper presents data on the cellular localization of the testis-expressed mouse Cyrn gene product, cyritestin [3].

Biological context of Adam3

• Synthesis, processing, and subcellular localization of mouse ADAM3 during spermatogenesis and epididymal sperm transport [4].
• These results demonstrate that the mature form of ADAM3 is involved in the binding of sperm to the egg zona pellucida, not in the membrane fusion between sperm and egg [4].

Anatomical context of Adam3

• This diminished amount of ADAM3 in the Triton X-114 detergent-enriched phase may explain the inability of Clgn(-/-) and Ace(-/-) sperm to bind to the zona pellucida [5].
• In Adam2-null males, most cyritestin (ADAM3) protein is also lost at this stage, but 25% of cyritestin is lost later, during sperm passage through the epididymis [6].
• The mature ADAM3 was localized on the anterior part of capacitated sperm heads and was rapidly removed from the head region during the calcium ionophore A23187-induced acrosome reaction [4].
• ADAM3 was initially synthesized as a 110-kDa precursor in round spermatids, and the precursor was then processed into a 42-kDa mature protein during the sperm transport into and/or once in the epididymis [4].
• To elucidate synthesis, processing, and subcellular localization of mouse ADAM3 (cyritestin) during spermatogenesis and epididymal sperm transport, we carried out immunoblotting and immunohistochemical analysis of testicular germ cells, and epididymal and vas deferens sperm, using affinity-purified anti-ADAM3 antibody [4].

Associations of Adam3 with chemical compounds

• In the Ace(-/-) mice, while ADAM2 was found normally in the sperm, ADAM3 disappeared from the Triton X-114 detergent-enriched phase after phase separation, which suggests that ACE is involved in distributing ADAM3 to a location where it can participate in sperm-zona pellucida binding [5].
• The sperm surface antigen tMDC I (also known as cyritestin) has been proposed to play a role in sperm-egg binding in the mouse via an interaction between its disintegrin-like domain and an integrin receptor on the oolemma plasma membrane [7].

Other interactions of Adam3

• Adam2-null and Adam3-null male mice exhibit reduced levels of one or more ADAM proteins on mature sperm, in addition to the loss of the genetically targeted protein [6].
• ADAM3 was absent from Clgn(-/-) sperm [5].

Analytical, diagnostic and therapeutic context of Adam3

• The absence of a tMDC I protein is further supported by the lack of immunoreactivity on Western blots of human testis and sperm extracts probed with macaque (Macaca fascicularis) and human anti-tMDC I antisera [7].

References