ECHINOCOCCUS-GRANULOSUS MYOPHILIN - RELATIONSHIP WITH PROTEIN HOMOLOGS CONTAINING CALPONIN-MOTIFS

Myophilin, a smooth-muscle protein of the tapeworm Echinococcus granul osus, was recently postulated to be a member of the calponin family of proteins. A detailed genetic analysis revealed that 17 proteins had s ignificant homology with the amino-acid sequence of the N-terminal reg ion of myophilin and/or possessed one or more ''calponin-motifs''. Com parison of the amino-acid sequences of the N-terminus showed that the homologous proteins clustered into distinct groups based on the number of calponin-motifs. The calponin-motif of myophilin was genetically m ore similar to that present in the muscle protein mp20 of Drosophila m elanogaster than to those in any other homologous proteins of vertebra tes. The existence of a distinct motif which is ''conserved'' in other proteins across a range of species suggests an important functional r ole for the motif. (C) 1997 Australian Society for Parasitology. Publi shed by Elsevier Science Ltd.