Isolation and localization of filamin in heart muscle.

High-molecular-mass protein was isolated from chicken heart muscle. The apparent molecular mass of a single polypeptide chain is similar to that of chicken gizzard filamin: 250-270 kDa. The protein interacts with antibodies against chicken gizzard filamin and induces F-actin gelation in a concentration-dependent manner.

Purification of a 175-kDa membrane protein, its localization in smooth and cardiac muscles. Interaction with cytoskeletal protein - vinculin.

A new 175-kDa membrane protein was isolated from chicken gizzard smooth muscle. Antibodies to 175-kDa protein were used for localization of this protein in smooth and cardiac muscles. In both types of muscle 175-kDa protein was localized near plasma membrane.

The role of actin-binding proteins vinculin, filamin, and fibronectin in intracellular and intercellular linkages in cardiac muscle.

The localization in cardiac muscle and the biochemical properties of fibronectin, filamin, and vinculin were studied. Fibronectin was localized between cardiomyocytes. Filamin was identified in the Z-line region of sarcomers and in the intercalated disks of heart muscle.

Identification and isolation of vinculin from platelets.

A vinculin-like protein was identified in chicken as well as in bovine platelets by ELISA competitive binding assay using antibodies against vinculin from chicken gizzard. By a modified procedure (J. Biol.

Vinculin localization in cardiac muscle.

Vinculin isolated from chicken cardiac muscle crossreacts with antibodies against smooth muscle vinculin. Antibodies to vinculin were used for localization of vinculin in cardiac muscle by indirect immunofluorescence method. In cardiac muscle vinculin was localized in intercalated discs and near plasma membrane at the cell periphery between external myofibrils and sarcolemma.