MOLECULAR-CLONING OF CDNA FOR LYSENIN, A NOVEL PROTEIN IN THE EARTHWORM EISENIA-FOETIDA THAT CAUSES CONTRACTION OF RAT VASCULAR SMOOTH-MUSCLE

Lysenin, which causes contraction of rat vascular smooth muscle, is a protein that was isolated from the earthworm Eisenia foetida. A cDNA e ncoding lysenin was isolated by use of a partial cDNA probe that had b een generated by the PCR with a primer designed by reference to an int ernal peptide sequence of lysenin. This clone had an ORF encoding 297 amino acid residues. The amino acid sequence deduced from the cDNA rev ealed the absence of any significant homology to those of previously c haracterized vasoactive substances. The recombinant lysenin was produc ed in Escherichia coli. This protein and native lysenin isolated from the earthworm had similar contractive activities when tested on rat ao rta. Northern blot analysis of the RNA from various tissues of the ear thworm indicated that lysenin is produced by the coelomocytes. (C) 199 7 Elsevier Science B.V.