Conversion of procaspase-3 to an autoactivating caspase by fusion to the caspase-2 prodomain.
Caspases are cysteine proteases that play an essential role in apoptosis. Initial activation of caspases defines the key step in apoptotic execution. Based on primary structure, caspases can be divided into two groups, those with long amino-terminal prodomains (class I), and those with relatively short prodomains (class II). On overexpression in mammalian cells, class I caspases can induce cell death that is dependent on their autocatalytic activity. Recent studies suggest that the long prodomains in some class I caspases are able to mediate dimerization of procaspase molecules, thereby promoting autoprocessing. In this communication, we demonstrate that fusion of the prodomain of a class I caspase (Nedd2/caspase-2) with procaspase-3 greatly augments autocatalysis and apoptosis induction by the chimeric caspase-3 molecule. The chimeric caspase-3 molecules were able to form homodimers in Saccharomyces cerevisiae and were efficiently processed in transfected mammalian cells. These results provide direct evidence for a role of a class I caspase prodomain in caspase autoactivation and processing and establish a basis for functional hierarchy among the two classes of caspases.
Hanson Centre for Cancer Research, Institute of Medical and Veterinary Science, Frome Road, Adelaide, SA 5000, Australia.
P A
PA
Colussi
N L
NL
Harvey
L M
LM
Shearwin-Whyatt
S
S
Kumar
D016475:3T3 Cells; D000818:Animals; D017209:Apoptosis; D001483:Base Sequence; D053143:Caspase 2; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism*; D017931:DNA Primers; D019281:Dimerization; D004789:Enzyme Activation; D004792:Enzyme Precursors / Q000378:metabolism*; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000378:metabolism; D051379:Mice; D011499:Protein Processing, Post-Translational; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism
D017931:DNA Primers; D004792:Enzyme Precursors; D008164:Luminescent Proteins; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; C505409:Casp3 protein, mouse; D053143:Caspase 2; D053148:Caspase 3; D020169:Caspases