Variable and constant regions in the C-terminus of vinculin and metavinculin. Cloning and expression of fragments in E. coli.

Metavinculin differs from vinculin in having an additional insert of 68 to 79 amino acids in length in the C-terminal half of the molecule. Cross-species comparison of metavinculin sequences from pig, man, chicken and frog reveals a division of the insert into two parts: the first variable and the second highly conserved. The longest insert, 79 amino acids, was found in Xenopus laevis. Three different C-terminal constructs of vinculin and metavinculin over-expressed in E. coli could be purified by column chromatography. Two-dimensional gel electrophoresis and peptide analysis revealed pI values between 8.35 and 10.25 for the recombinant proteins. Biochemical and structural features of the metavinculin-specific sequence and the conserved vinculin/metavinculin carboxy-terminus are discussed.