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 subun it (MBS) of smooth muscle myosin phosphatase. In MDCK cells in a confl uent 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 l ocalized at the adherens junction. Furthermore, MBS was translocated r eversibly between the cytosol and the cell-cell adhesion sites during the formation and disappearance of cell-cell contacts. These data sugg est that MBS may play an important role in the regulation of the cell- cell adhesion. (C) 1997 Academic Press.