Signal Transduction - The Scientist - Magazine of the Life Sciences
Abstract
T. Fernandes-Alnemri, R.C. Armstrong, J. Krees, S.M. Srinivasula, L. Wang, F. Bullrich, L.C. Fritz, J.A. Trapani, K.J. Tomaselli, G. Litwack, E.S. Alnemri, "In vitro activation of CPP32 and Mch3 by Mch4, a novel human apoptotic cysteine protease containing two FADD-like domains," Proceedings of the National Academy of Sciences, 93:7464-9, 1996. (Cited in more than 185 papers since publication) Comments by Emad S. Alnemri, associate professor and deputy director of the Center for Apoptosis Research, The Kimmel Cancer Center at Thomas Jefferson University in Philadelphia To understand the function of a caspase, researchers must look at the long and short of it. All caspases--aspartate-specific cystein proteases that mediate apoptosis and proinflammatory cytokine production--share structural similarities: a prodomain, a large subunit, and a small subunit. However, differences in the lengths of caspase prodomains may be especially significant, notes Emad S. Alnemri, whose lab has discovered seven of the 14 known caspases. "What is the function of the prodomain?" Alnemri asks rhetorically. "The ones that have short prodomains appear to be downstream, or effector, caspases." Those inactive zymogens depend on the upstream caspases to convert them into active proteases. So far, caspase 3, (CPP32), caspase 6 (Mch2) and caspase 7 (Mch3)