Tetraspanins are cell membrane-scaffolding proteins interacting with one another and a repertoire of interaction partners. Through these interactions, they form extended molecular networks as tetraspanin webs or tetraspanin-enriched microdomains. Microscopic data suggest that these networks contain tetraspanin clusters, with poor overlap between clusters formed by different tetraspanins. Here, ...

Recent studies brought the evidences that some cell surface molecules associated with immune system (cluster of differentiation (CD) molecules) may be involved in the fertilization process. The experimental observations regarding the function of CD9, CD49f/CD29, CD46 and CD11b/CD18 have led to the construction of general hypothesis of fertilization comprising the interaction of these CD molecul...

The surface expression of CD9 (cluster-of-differentiation antigen-9) in sperms of certain mammalian species has been attributed to its fusion with the egg and thereby dictating the fertility of species. In the present study, we investigated the association of CD9 with crossbred bull sperm quality and quantity trait was analyzed using a total of 96 Frieswal (HF × Sahiwal) crossbred. A single nuc...

Sperm-egg binding and fusion initiate the development of a new organism, but the molecular mechanisms of gamete adhesion, gamete membrane fusion and associated signaling are still poorly understood. Recently, one egg surface protein, CD9, was shown to be essential for gamete fusion. The fertility of CD9-deficient female mice is severely reduced because membrane fusion ability is lost in CD9-def...

EpCAM, epithelial membrane antigen (EMA)-mucin 1 (MUC1), mesothelin, and CD9 have been reported to be overexpressed at the RNA level in ovarian carcinomas. By using immunohistochemistry, we profiled the protein expression of these gene products in ovarian carcinoma tissues and compared them with benign ovarian surface epithelium (OSE) and cortical inclusion cysts (CICs). Immunoreactivity for EM...

We analyzed herein whether members of the tetraspanin superfamily are involved in human immature dendritic cell (DC) functions such as foreign antigen internalization, phagocytosis, and cell migration. We show that CD63, CD9, CD81, CD82, and CD151 are present in immature DCs. Whereas CD9 and CD81 are mostly expressed at the cell surface, CD63 and CD82 are also located in intracellular organelle...

Little is known about the molecular mechanisms that induce gamete fusion during mammalian fertilization. After initial contact, adhesion between gametes only leads to fusion in the presence of three membrane proteins that are necessary, but insufficient, for fusion: Izumo1 on sperm, its receptor Juno on egg and Cd9 on egg. What happens during this adhesion phase is a crucial issue. Here, we dem...

Transgenic mouse lines were created that express Fc gamma RIIA on platelets and macrophages at human physiologic levels, and they were used to explore the consequences in vivo of activating antiplatelet antibodies. Anti-CD9 antibody activated platelets of Fc gamma RIIA transgenic (tg) mice and, following injection in vivo, caused more rapid severe thrombocytopenia than nonactivating antiplatele...

Hematopoietic progenitor cells are the progeny of hematopoietic stem cells that coordinate the production of precise numbers of mature blood cells of diverse functional lineages. Identification of cell-surface antigen expression associated with hematopoietic lineage restriction has allowed prospective isolation of progenitor cells with defined hematopoietic potential. To clarify further the cel...

We have recently found that CD9, a cell surface glycoprotein involved in intercellular signaling in hematopoietic cells, is also expressed by neurons and glia in the peripheral nervous system. Antibody perturbation experiments were conducted to examine the function of CD9 in neural cells. Three anti-CD9 monoclonal antibodies (mAbs) (ROCA1, ROCA2, B2C11) were tested for their ability to promote ...