NONMUSCLE MYOSIN-II HEAVY-CHAIN HAS A CRYPTIC CELL-ADHESION DOMAIN

We have discovered a cryptic cell-adhesion domain in non-muscle myosin II heavy chain. A 205 kDa cell-adhesion-promoting polypeptide (p205) was extracted from BHK cells by Nonidet P-40 or Dounce homogenization. Adhesion to p205 was specifically inhibited by the peptide Gly-Arg-Gl y-Asp-Ser-Pro, indicating a role for the Arg-Gly-Asp cell-adhesion mot if. Purified p205 was identified as non-muscle myosin II heavy chain, based on sequence analysis and on the cross-reactivity of p205 with an ti-(bovine trachea myosin) antibodies. Further experiments showed that the heavy chain of purified myosin II has cell-adhesion-promoting act ivity in a cell-blotting assay, and cross-reacted with anti-p205 antib odies. Finally, the adhesion domain was located int he tail portion of myosin II heavy chain, where an Arg-Gly-Asp-containing sequence can b e found.