Activin A induces expression of rat Sel-1l mRNA, a negative regulator of notch signaling, in rat salivary gland-derived epithelial cells

We previously established a rat submandibular gland (SMG)-derived epithelia l cell line (RSMG-1) to study the mechanism of morphogenesis in salivary gl and development and regeneration. We found that activin A regulated the bra nching morphogenesis of RSMG-1 cells, suggesting that it is involved in SMG morphogenesis, We used a subtraction cloning procedure with activin-A-trea ted and untreated RSMG-1 cells to identify activin-A-induced genes. One of the genes detected encoded a rat homologue of Sel-1l (rSel-1l), rSel-1l is a mammalian homologue of C, elegans sel-1, which is a negative regulator of Notch signaling. In this study, we confirmed that activin A induces rSel-1 l mRNA expression in RSMG-1 cells, and that rSel-1l is expressed in SMG aci nar cells. These results suggest that activin A regulates the differentiati on of RSMG-1 cells to acinar cells. (C) 2001 Academic Press.