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.
Alves
Juliano
J
Department of Molecular Biology, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92037, USA. jalves@gnf.org
Wurdak
Heiko
H
Garay-Malpartida
Humberto M
HM
Harris
Jennifer L
JL
Occhiucci
João M
JM
Belizário
José E
JE
Li
Jun
J
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