TAF15 and the leukemia-associated fusion protein TAF15-CIZ/NMP4 are cleaved by caspases-3 and -7.
Caspases are central players in proteolytic pathways that regulate cellular processes such as apoptosis and differentiation. To accelerate the discovery of novel caspase substrates we developed a method combining in silico screening and in vitro validation. With this approach, we identified TAF15 as a novel caspase substrate in a trial study. We find that TAF15 was specifically cleaved by caspases-3 and -7. Site-directed mutagenesis revealed the consensus sequence 106DQPD/Y110 as the only site recognized by these caspases. Surprisingly, TAF15 was cleaved at more than one site in staurosporine-treated Jurkat cells. In addition, we generated two oncogenic TAF15-CIZ/NMP4-fused proteins which have been found in acute myeloid leukemia and demonstrate that caspases-3 and -7 cleave the fusion proteins at one single site. Broad application of this combination approach should expedite identification of novel caspase-interacting proteins and provide new insights into the regulation of caspase pathways leading to cell death in normal and cancer cells.
Department of Molecular Biology, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92037, USA. jalves@gnf.org
Juliano
J
Alves
Heiko
H
Wurdak
Humberto M
HM
Garay-Malpartida
Jennifer L
JL
Harris
João M
JM
Occhiucci
José E
JE
Belizário
Jun
J
Li
D017209:Apoptosis; D053148:Caspase 3 / Q000378:metabolism*; D006801:Humans; D019169:Jurkat Cells; D015470:Leukemia, Myeloid, Acute / Q000378:metabolism*; D015514:Oncogene Proteins, Fusion / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D013379:Substrate Specificity; D035381:TATA-Binding Protein Associated Factors / Q000235:genetics / Q000378:metabolism*; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*
D015514:Oncogene Proteins, Fusion; D011993:Recombinant Fusion Proteins; C102041:TAF15 protein, human; D035381:TATA-Binding Protein Associated Factors; D015534:Trans-Activators; C498621:ZNF384 protein, human; D053148:Caspase 3