EC - HtrA2 peptidase

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IntEnz Enzyme Nomenclature


Accepted name:
HtrA2 peptidase
Other names:
high temperature requirement protein A2
Omi stress-regulated endoprotease
serine proteinase OMI
HtrA2 protease
OMI/HtrA2 protease
Systematic name:



This enzyme is upregulated in mammalian cells in response to stress induced by both heat shock and tunicamycin treatment [4]. It can induce apoptosis in a caspase-independent manner through its peptidase activity and in a caspase-dependent manner by disrupting the interaction between caspase and the inhibitor of apoptosis (IAP) [3]. Belongs in peptidase family S1B.

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , MEROPS , UniPathway
Structural data: CSA , EC2PDB
UniProtKB/Swiss-Prot: (18) [show] [UniProt]


  1. Srinivasula, S.M., Gupta, S., Datta, P., Zhang, Z., Hegde, R., Cheong, N., Fernandes-Alnemri, T. and Alnemri, E. S.
    Inhibitor of apoptosis proteins are substrates for the mitochondrial serine protease Omi/HtrA2.
    J. Biol. Chem. 278 : 31469-31472 (2003). [PMID: 12835328]
  2. Savopoulos, J.W., Carter, P.S., Turconi, S., Pettman, G.R., Karran, E. H., Gray, C.W., Ward, R.V., Jenkins, O. and Creasy, C.L.
    Expression, purification, and functional analysis of the human serine protease HtrA2.
    Protein Expr. Purif. 19 : 227-234 (2000). [PMID: 10873535]
  3. Martins, L.M., Turk, B.E., Cowling, V., Borg, A., Jarrell, E.T., Cantley, L.C. and Downward, J.
    Binding specificity and regulation of the serine protease and PDZ domains of HtrA2/Omi.
    J. Biol. Chem. 278 : 49417-49427 (2003). [PMID: 14512424]
  4. Gray, C.W., Ward, R.V., Karran, E., Turconi, S., Rowles, A., Viglienghi, D., Southan, C., Barton, A., Fantom, K.G., West, A., Savopoulos, J., Hassan, N.J., Clinkenbeard, H., Hanning, C., Amegadzie, B., Davis, J.B., Dingwall, C., Livi, G.P. and Creasy, C.L.
    Characterization of human HtrA2, a novel serine protease involved in the mammalian cellular stress response.
    Eur. J. Biochem. 267 : 5699-5710 (2000). [PMID: 10971580]
  5. Li, W., Srinivasula, S.M., Chai, J., Li, P., Wu, J.-W., Zhang, Z., Alnemri, E.S. and Shi, Y.
    Structural insights into the pro-apoptotic function of mitochondrial serine protease HtrA2/Omi.
    Nat. Struct. Biol. 9 : 436-441 (2002). [PMID: 11967569]

[EC created 2006]