Expression and Functional Characterization of the Adhesion Molecule Spermatogenic Immunoglobulin Superfamily in the Mouse Testis1

Abstract

Spermatogenic immunoglobulin superfamily (SgIGSF) is a mouse protein belonging to the immunoglobulin superfamily expressed in the spermatogenic cells of seminiferous tubules. We produced a specific polyclonal antibody against SgIGSF. Western blot analysis of the testes from postnatal developing mice using this antibody demonstrated multiple immunopositive bands of 80-130 kDa, which increased in number and size with the postnatal age. Enzymatic N-glycolysis caused reduction in the size of these bands to 70 kDa, indicating that SgIGSF is a glycoprotein and its glycosylation pattern and extent are developmentally regulated. Immunohistochemical analysis of the adult testis demonstrated that SgIGSF was present in the spermatogenic cells in the earlier steps of spermatogenesis and increased in amount from intermediate spermatogonia through zygotene spermatocytes but was diminished in the steps from early pachytene spermatocytes through round spermatids. After meiosis, SgIGSF reappeared in step 7 spermatids and was present in the elongating spermatids until spermiation. The immunoreactivity was localized primarily on the cell membrane. Consistent with the findings in adult testes, the analysis of the developing testes revealed that SgIGSF was expressed separately in the spermatogenic cells in earlier and later phases. Sertoli cells had no expression of SgIGSF, whereas both SgIGSF immunoprecipitated from the testis lysate and produced in COS-7 cells was shown to bind to the surface of Sertoli cells in primary culture. These results suggested that SgIGSF on the surface of spermatogenic cells binds to some membrane molecules on Sertoli cells in a heterophilic manner and thereby may play diverse roles in the spermatogenesis.

Expression of the tumour suppressor gene CADM1 is associated with favourable outcome and inhibits cell survival in neuroblastoma

“…Previous investigations have supported the hypothesis of CADM1 as a general tumour suppressor-mediating apoptosis (Mao et al, 2004), differentiation (Wakayama et al, 2003) and cell cycle regulation (Ito et al, 2003b). We recently found In northern blot analysis, only mRNA levels of the recombinant CADM1 transcript are shown, which is shorter than the endogenous transcript.…”

Six cadm/synCAM genes are expressed in the nervous system of developing zebrafish

“…The Cadms (cell adhesion molecules) are a family of type I transmembrane proteins that have been described in several pathological and physiological processes such as the progression of lung and other cancers (reviewed in Murakami, 2005), mast cell adhesion (Ito et al, 2003(Ito et al, , 2007bFuruno et al, 2005;Ito and Oonuma, 2006), spermatogenesis (Wakayama et al, 2001;Wakayama et al, 2003;Fujita et al, 2006;van der Weyden et al, 2006;Yamada et al, 2006), epithelium development and homeostasis (Ito et al, 2007b), and central nervous system development (Biederer et al, 2002;Sara et al, 2005;Spiegel et al, 2007).…”

Expression of cell adhesion molecule 1 in malignant pleural mesothelioma as a cause of efficient adhesion and growth on mesothelium

“…8 Structurally, this adhesion molecule has three immunoglobulin-like motifs in the extracellular domain and a short cytoplasmic domain that interacts with other proteins via the protein 4.1-binding and PDZbinding motifs. 4,7 A variety of cells express CADM1, including epithelial cells, such as pulmonary and biliary epithelial cells, 9,10 and non-epithelial cells, such as neurons, 6 spermatogenic cells, 4,11 and mast cells. 12 CADM1 forms homodimers on the cell membrane through cis-interactions, and binds either trans-homophilically or heterophilically, depending on the cell type expressing the CADM1 and the binding partners available on adjacent cells.…”

“…12 CADM1 forms homodimers on the cell membrane through cis-interactions, and binds either trans-homophilically or heterophilically, depending on the cell type expressing the CADM1 and the binding partners available on adjacent cells. The trans-homophilic binding occurs among neurons 6 and between mast cells and neurons, 13 and the transheterophilic binding occurs between mast cells and fibroblasts 11 and between spermatogenic and Sertoli cells. 8 In addition to the full-length form of approximately 100 kDa, CADM1 appears to have a shorter form of about 35 kDa, which is probably generated by N-terminal truncation of the full-length form, as suggested in murine mast cells; 12 however, the function of this truncated form remains unclear.…”