Myosin binding subunit of smooth muscle myosin phosphatase at the cell-cell adhesion sites in MDCK cells.

We examined the intracellular localization of the myosin binding subunit (MBS) of smooth muscle myosin phosphatase. In MDCK cells in a confluent monolayer of polarized epithelial sheet, MBS was concentrated to the cell-cell adhesion sites. Double-immunofluorescence analysis with anti-MBS and anti-beta-catenin antibodies showed that MBS was mainly localized at the adherens junction. Furthermore, MBS was translocated reversibly between the cytosol and the cell-cell adhesion sites during the formation and disappearance of cell-cell contacts. These data suggest that MBS may play an important role in the regulation of the cell-cell adhesion.