Intermediate filament cDNAs from BHK-21 cells: demonstration of distinct genes for desmin and vimentin in all vertebrate classes

Abstract

Recombinant cDNA plasmids for the intermediate filament proteins desmin and vimentin were constructed from baby hamster kidney (BHK-21) mRNA. Analysis of four desmin clones gave a sequence of 1574 nucleotides, which is 75% of the total mRNA length. The derived amino acid sequence for hamster desmin shows 92% overall homology with chicken desmin; the homology with hamster vimentin is highest in the alpha-helical middle part (74%). The 3'-noncoding region of desmin mRNA is found to be 677 nucleotides long. With the aid of 5'- and 3'-specific probes, it has been established that there is a single gene for desmin in the hamster genome. This gene expresses a single mRNA species of 2.2 kilobases. Hybridization experiments of a number of DNAs with desmin and vimentin probes show that there are distinct restriction enzyme fragments carrying vimentin and desmin sequences in the genome of representatives of all vertebrate classes.