The interaction between PmHtrA2 and PmIAP and its effect on the activity of Pm caspase.
Apoptosis is an essential mechanism in multicellular organisms which results in the induction of cell death. Important apoptotic proteins, including high temperature requirement A2 (PmHtrA2; also known as serine protease), inhibitor of apoptosis protein (PmIAP) and Pm caspase, have been previously identified in black tiger shrimp, Penaeus monodon. However, the relevance among these proteins in apoptosis regulation has not been established yet in shrimp. Here, we showed that PmHtrA2 was able to interact with PmIAP and the binding of the two proteins was mediated by the BIR2 domain of PmIAP. In addition, the BIR2 of PmIAP was shown to be able to inhibit Pm caspase activity. The inhibitory effect of the BIR2 domain on Pm caspase was impaired under the presence of the IBM peptide of PmHtrA2, implying a role for PmHtrA2 in apoptosis activation. Our combined results suggested that P. monodon possesses a conserved mechanism by which the caspase-3 activity is modulated by HtrA2 and IAP, as previously seen in insects and mammals.
Department of Microbiology, Faculty of Science, King Mongkut's University of Technology Thonburi, Bangkok 10140, Thailand.
Anchulee
A
Saleeart
Department of Microbiology, Faculty of Science, King Mongkut's University of Technology Thonburi, Bangkok 10140, Thailand.
Karntichar
K
Mongkorntanyatip
Aquatic Molecular Genetics and Biotechnology Laboratory, National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), 113 Paholyothin Road, Klong 1, Klongluang, Pathumthani 12120, Thailand.
Pakkakul
P
Sangsuriya
National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathumthani 12120, Thailand; Center of Excellence for Shrimp Molecular Biology and Biotechonology, Mahidol University, 272 Rama VI Road, Bangkok, 10400, Thailand.
Saengchan
S
Senapin
Department of Microbiology, Faculty of Science, King Mongkut's University of Technology Thonburi, Bangkok 10140, Thailand.
Triwit
T
Rattanarojpong
Department of Microbiology, Faculty of Science, King Mongkut's University of Technology Thonburi, Bangkok 10140, Thailand. Electronic address: pongsak.khu@kmutt.ac.th.
Pongsak
P
Khunrae
D000818:Animals; D017209:Apoptosis; D060829:Arthropod Proteins / Q000235:genetics* / Q000378:metabolism; D020169:Caspases / Q000235:genetics* / Q000378:metabolism*; D051034:Inhibitor of Apoptosis Proteins / Q000235:genetics* / Q000378:metabolism; D033561:Penaeidae / Q000201:enzymology* / Q000235:genetics; D017422:Sequence Analysis, DNA; D012697:Serine Endopeptidases / Q000235:genetics* / Q000378:metabolism
D060829:Arthropod Proteins; D051034:Inhibitor of Apoptosis Proteins; D012697:Serine Endopeptidases; D020169:Caspases
Apoptosis; Penaeus monodon; Pm caspase; PmHtrA2; PmIAP