EVIDENCE THAT THE CHICK LENS CYTOSKELETAL PROTEIN CP-49 BELONGS TO THE FAMILY OF INTERMEDIATE FILAMENT PROTEINS

A partial cDNA sequence for chick lens beaded-filament protein CP 49 s howed the greatest similarity to the sequence of acidic cytokeratins, especially human cytokeratin 18. The predicted amino acid sequence of chick CP 49 corresponded to the entire coil la region of the rod domai n of human cytokeratin 18, spacer 1, coil 1 b, spacer 2 and about half of coil 2. For this sequence of 242 amino acids, there was an overall 38% identity and 76.8% similarity between the chick CP 49 and human c ytokeratin 18. This is further evidence that CP 49 belongs to the fami ly of intermediate filament proteins.