- The exonucleolytic and endonucleolytic cleavage activities of human exonuclease 1 are stimulated by an interaction with the carboxyl-terminal region of the Werner syndrome protein. Sharma, S., Sommers, J.A., Driscoll, H.C., Uzdilla, L., Wilson, T.M., Brosh, R.M. J. Biol. Chem. (2003)