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Product listing: Cleaved Drosophila ICE (drICE) (Asp230) Antibody, UniProt ID O01382 #9478 to HtrA2 Antibody, UniProt ID O43464 #2176

$303
100 µl
APPLICATIONS
REACTIVITY
D. melanogaster

Application Methods: Western Blotting

Background: Cell death in the fruit fly Drosophila melanogaster is regulated by many of the same stimuli as mammalian cell death (1). The Drosophila genome contains seven caspase genes; three encode initiator caspases and four encode effector caspases (reviewed in 2). drICE is a cysteine protease that cleaves baculovirus p35 and lamin DmO in vitro and acts downstream of rpr (3). drICE is proteolytically processed during apoptosis into active p21 and p12 subunits. Comparison of the in vivo activity between drICE and Dcp-1 has shown that drICE is a more effective inducer of apoptosis than Dcp-1, which plays a role in determining the rate of cell death (4).

$303
100 µl
APPLICATIONS
REACTIVITY
Mouse

Application Methods: Western Blotting

Background: Gasdermin D (GSDMD), a member of the gasdermin family that includes GSDMA, GSDMB, and GSMDC, has been reported to have a critical role as a downstream effector of pyroptosis (1,2). Pyroptosis is a lytic type of cell death triggered by inflammasomes, multiprotein complexes assembled in response to pathogen-associated molecular patterns (PAMPs) or danger-associated molecular patterns (DAMPs) that result in the activation of caspase-1 and subsequent cleavage of pro-inflammatory cytokines IL-1β and IL-18 (3). Gasdermin D was identified by two independent groups as a substrate of inflammatory caspases, caspase-1 and caspase-11/4/5, producing two fragments: GSDMD-N and GSDMD-C. Cleavage results in release of an intramolecular inhibitory interaction between the N- and C-terminal domains, allowing the N-terminal fragment GSMDM-N to initiate pyroptosis through the formation of pores on the plasma membrane (4-7).

$303
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Western Blotting

Background: Lamins are nuclear membrane structural components that are important in maintaining normal cell functions such as cell cycle control, DNA replication, and chromatin organization (1-3). Lamin A/C is cleaved by caspase-6 and serves as a marker for caspase-6 activation. During apoptosis, lamin A/C is specifically cleaved into a large (41-50 kDa) and a small (28 kDa) fragment (3,4). The cleavage of lamins results in nuclear dysregulation and cell death (5,6).

$303
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Immunofluorescence (Immunocytochemistry), Immunohistochemistry (Paraffin), Western Blotting

Background: Lamins are nuclear membrane structural components that are important in maintaining normal cell functions such as cell cycle control, DNA replication, and chromatin organization (1-3). Lamin A/C is cleaved by caspase-6 and serves as a marker for caspase-6 activation. During apoptosis, lamin A/C is specifically cleaved into a large (41-50 kDa) and a small (28 kDa) fragment (3,4). The cleavage of lamins results in nuclear dysregulation and cell death (5,6).

$122
20 µl
$303
100 µl
$717
300 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Western Blotting

Background: PARP, a 116 kDa nuclear poly (ADP-ribose) polymerase, appears to be involved in DNA repair in response to environmental stress (1). This protein can be cleaved by many ICE-like caspases in vitro (2,3) and is one of the main cleavage targets of caspase-3 in vivo (4,5). In human PARP, the cleavage occurs between Asp214 and Gly215, which separates the PARP amino-terminal DNA binding domain (24 kDa) from the carboxy-terminal catalytic domain (89 kDa) (2,4). PARP helps cells to maintain their viability; cleavage of PARP facilitates cellular disassembly and serves as a marker of cells undergoing apoptosis (6).

$122
20 µl
$303
100 µl
APPLICATIONS
REACTIVITY
Mouse

Application Methods: Western Blotting

Background: PARP, a 116 kDa nuclear poly (ADP-ribose) polymerase, appears to be involved in DNA repair in response to environmental stress (1). This protein can be cleaved by many ICE-like caspases in vitro (2,3) and is one of the main cleavage targets of caspase-3 in vivo (4,5). In human PARP, the cleavage occurs between Asp214 and Gly215, which separates the PARP amino-terminal DNA binding domain (24 kDa) from the carboxy-terminal catalytic domain (89 kDa) (2,4). PARP helps cells to maintain their viability; cleavage of PARP facilitates cellular disassembly and serves as a marker of cells undergoing apoptosis (6).

$122
20 µl
$303
100 µl
APPLICATIONS
REACTIVITY
Rat

Application Methods: Western Blotting

Background: PARP, a 116 kDa nuclear poly (ADP-ribose) polymerase, appears to be involved in DNA repair in response to environmental stress (1). This protein can be cleaved by many ICE-like caspases in vitro (2,3) and is one of the main cleavage targets of caspase-3 in vivo (4,5). In human PARP, the cleavage occurs between Asp214 and Gly215, which separates the PARP amino-terminal DNA binding domain (24 kDa) from the carboxy-terminal catalytic domain (89 kDa) (2,4). PARP helps cells to maintain their viability; cleavage of PARP facilitates cellular disassembly and serves as a marker of cells undergoing apoptosis (6).

$303
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Western Blotting

Background: Fodrin (also named nonerythroid spectrin) is a universally expressed membrane-associated cytoskeletal protein consisting of alpha- and beta-subunits (1). This protein is important for maintaining normal membrane structure and supporting cell surface protein function (1). Alpha-fodrin is one of the primary targets cleaved by caspases during apoptosis. The full length 240 kDa protein can be cleaved at several sites within its sequence by activated caspases to yield amino-terminal 150 kDa, carboxy-terminal 120 kDa and 35 kDa major products (2-5). Cleavage of alpha-fodrin leads to membrane malfunction and cell shrinkage.

$111
20 µl
$260
100 µl
APPLICATIONS
REACTIVITY
D. melanogaster, Human, Monkey, Mouse, Rat

Application Methods: Immunohistochemistry (Paraffin), Western Blotting

Background: Cytochrome c is a well conserved electron-transport protein and is part of the respiratory chain localized to mitochondrial intermembrane space (1). Upon apoptotic stimulation, cytochrome c released from mitochondria associates with procaspase-9 (47 kDa)/Apaf 1. This complex processes caspase-9 from inactive proenzyme to its active form (2). This event further triggers caspase-3 activation and eventually leads to apoptosis (3).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Immunoprecipitation, Western Blotting

Background: Death associated protein 1 (DAP1) is a 15 kDa protein that functions as a positive mediator of cell death initiated by interferon-gamma (1, 2). The DAP1 protein is proline rich and possesses one SH3 binding motif, as well as several consensus protein kinase phosphorylation sites (1). The protein is localized in the cytoplasm, but the detailed mechanism of its proapoptotic function is unclear. Death associated protein 3 (DAP3) is widely expressed, and the expression is upregulated during membrane receptor-mediated apoptosis. In interferon-gamma- and Fas-induced apoptosis, DAP3 acts as a positive mediator, functioning downstream of the receptor signaling complex and upstream of the effector caspases (3,4). Death associated protein 5 (DAP5) is a 97 kDa protein with a high degree of amino acid sequence homology to eukaryotic translation initiation factor 4G (Elf4G) (1,5). Compared with elF4G, DAP5 lacks the amino-terminal region necessary for cap-dependent translation, and has a unique carboxy-terminal region that functions as a regulator of interferon-gamma-induced cell death (5,6). During induction of apoptosis, DAP5 is cleaved at aspartic acid 790. The carboxy-terminal truncated form of DAP5 functions as a cap-independent translation initiation factor responsible for the mediation of its own translation during apoptosis (7).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse

Application Methods: Western Blotting

Background: Death-associated protein kinase (DAPK1) is a Ca2+/calmodulin-regulated serine/threonine kinase that participates in a wide range of apoptotic signals including interferon-γ, tumor necrosis factor α, Fas, activated c-Myc, and detachment from the extracellular matrix. In addition to the kinase domain and calmodulin regulatory segment, DAPK1 also has eight ankyrin repeats, a cytoskeleton binding region, and a conserved death domain (1-3). Deletion of the calmodulin-regulatory domain generates a constitutively active mutant kinase. Ectopic expression of wild-type DAPK1 induced cell death in HeLa cells. Conversely, expression of a catalytically inactive mutant protected cells from interferon-γ-induced cell death (4). The catalytic domain of DAPK1 has very high sequence similarity to vertebrate myosin light chain kinase (MLCK) and a RXX(S/T)X motif derived from myosin light chain protein was shown to be phosphorylated in vitro by DAPK1 (5).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Western Blotting

Background: Death-associated protein kinase (DAPK1) is a Ca2+/calmodulin-regulated serine/threonine kinase that participates in a wide range of apoptotic signals including interferon-γ, tumor necrosis factor α, Fas, activated c-Myc, and detachment from the extracellular matrix. In addition to the kinase domain and calmodulin regulatory segment, DAPK1 also has eight ankyrin repeats, a cytoskeleton binding region, and a conserved death domain (1-3). Deletion of the calmodulin-regulatory domain generates a constitutively active mutant kinase. Ectopic expression of wild-type DAPK1 induced cell death in HeLa cells. Conversely, expression of a catalytically inactive mutant protected cells from interferon-γ-induced cell death (4). The catalytic domain of DAPK1 has very high sequence similarity to vertebrate myosin light chain kinase (MLCK) and a RXX(S/T)X motif derived from myosin light chain protein was shown to be phosphorylated in vitro by DAPK1 (5).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Western Blotting

Background: The tumor necrosis factor receptor family, which includes TNF-RI, Fas, DR3, DR4, DR5, and DR6, plays an important role in the regulation of apoptosis in various physiological systems (1,2). The receptors are activated by a family of cytokines that include TNF, FasL, and TRAIL. They are characterized by a highly conserved extracellular region containing cysteine-rich repeats and a conserved intracellular region of about 80 amino acids termed the death domain (DD). The DD is important for transducing the death signal by recruiting other DD containing adaptor proteins (FADD, TRADD, RIP) to the death-inducing signaling complex (DISC), resulting in activation of caspases.

$111
20 µl
$260
100 µl
APPLICATIONS
REACTIVITY
Human, Rat

Application Methods: Western Blotting

Background: The tumor necrosis factor receptor family, which includes TNF-RI, Fas, DR3, DR4, DR5, and DR6, plays an important role in the regulation of apoptosis in various physiological systems (1,2). The receptors are activated by a family of cytokines that include TNF, FasL, and TRAIL. They are characterized by a highly conserved extracellular region containing cysteine-rich repeats and a conserved intracellular region of about 80 amino acids termed the death domain (DD). The DD is important for transducing the death signal by recruiting other DD containing adaptor proteins (FADD, TRADD, RIP) to the death-inducing signaling complex (DISC), resulting in activation of caspases.

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Immunoprecipitation, Western Blotting

Background: Human DFF45 and its mouse homologue ICAD function in normal cells as chaperones for caspase-activated deoxyribonuclease (DFF40 or CAD) during its synthesis (1). The association of DFF45 (or its isoform DFF35) with DFF40 inhibits the DNAse activity of the latter (1-4). In vitro, DFF45 has been shown to be the target of several caspases, including caspase-3, -6, -7, -8 and granzyme B (3). In vivo, caspase-3 is believed to be the primary enzyme responsible for processing DFF45 and release of its carboxy-terminal fragment (3,5). The cleavage of DFF45 inactivates its inhibitory function on DFF40 and causes nuclear DNA degradation by DFF40, leading to cell death (6,7).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Western Blotting

Background: The putative transcription factor DIDO1 (death inducer obliterator 1, also termed DIO-1 or DATF1) contains a pair of zinc finger motifs and is upregulated by apoptotic stimuli. DIDO1 is expressed in the developing limb and may play a role in controlling programmed cell death during development (1-3). Nuclear translocation of DIDO1 during apoptosis is associated with its apoptotic activity (2). Alternative splicing produces the DIDO-1, -2 and -3 isoforms (also termed DIO-1, -2, -3), whose targeted disruption in mice produces a phenotype similar to myelodysplastic/myeloproliferative disease (MPS/MPD) in humans (3). DIDO3, the largest of the splice variants, is associated with the centrosome and plays a role in mitotic checkpoint and chromosome stability (4).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Western Blotting

Background: The tumor necrosis factor receptor family, which includes TNF-RI, Fas, DR3, DR4, DR5, and DR6, plays an important role in the regulation of apoptosis in various physiological systems (1,2). The receptors are activated by a family of cytokines that include TNF, FasL, and TRAIL. They are characterized by a highly conserved extracellular region containing cysteine-rich repeats and a conserved intracellular region of about 80 amino acids termed the death domain (DD). The DD is important for transducing the death signal by recruiting other DD containing adaptor proteins (FADD, TRADD, RIP) to the death-inducing signaling complex (DISC), resulting in activation of caspases.

$260
100 µl
APPLICATIONS
REACTIVITY
D. melanogaster

Application Methods: Western Blotting

Background: Cell death in the fruit fly Drosophila melanogaster is regulated by many of the same stimuli as mammalian cell death (1). The Drosophila genome contains seven caspase genes; three encode initiator caspases and four encode effector caspases (reviewed in 2). drICE is a cysteine protease that cleaves baculovirus p35 and lamin DmO in vitro and acts downstream of rpr (3). drICE is proteolytically processed during apoptosis into active p21 and p12 subunits. Comparison of the in vivo activity between drICE and Dcp-1 has shown that drICE is a more effective inducer of apoptosis than Dcp-1, which plays a role in determining the rate of cell death (4).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Western Blotting

Background: The initiation of translation is an important biological event and a variety of factors contribute to this process. Members of the eIF4 translation initiation factor family bind to the 5' m7GTP mRNA cap and unwind the mRNA secondary structure (1,2). The amino-terminal portion of eIF4G physically associates with eIF4E to stimulate the binding of eIF4E to the mRNA cap structure (3). eIF4G also interacts with eIF3 and eIF4A and serves as an adaptor molecule in the eIF4 complex (4). Moreover, eIF4G plays a role in internal ribosomal entry site (IRES)-mediated initiation of translation (5,6). The eIF4G family includes eIF4G1 (eIF4GI), eIF4G2 (p97, DAP5 or NAT1), and eIF4G3 (eIF4GII) (7). These factors share a homologous sequence that provides for interaction with initiation factors eIF3 and eIF4A. Both eIF4G1 and eIF4G3 are involved in cap-dependent translation, while eIF4G2 plays a role in IRES-mediated translation of some genes during cell stress (7,8).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Western Blotting

Background: Endonuclease G (EndoG) is a nuclear-encoded mitochondrial nuclease that has been reported to function in apoptosis, DNA recombination and cell proliferation (1-5). EndoG is expressed as a precursor protein containing an amino-terminal mitochondrial targeting sequence which is removed when the protein is imported into the mitochondria (1). During apoptosis EndoG is released from the mitochondria, translocates to the nucleus and cooperates with other nucleases to trigger DNA fragmentation associated with the apoptotic process (3,6,7).

$111
20 µl
$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Western Blotting

Background: Fas-associated death domain (FADD or Mort 1) functions as an important adaptor in coupling death signaling from membrane receptors, such as the Fas ligand and TNF family (DR3, DR4 and DR5), to caspase-8 (1,2). FADD has a carboxy-terminal death domain, which interacts with the cytoplasmic tail of the membrane receptor, and an amino-terminal death effector domain, which interacts with caspase-8. Clustering of the receptors upon stimulation brings about FADD and caspase-8 oligomerization, activating the caspase signaling pathway. Human FADD is phosphorylated mainly at Ser194, while mouse FADD is phosphorylated at Ser191. In both cases, the phosphorylation is cell cycle-dependent (3) and may be related to its regulatory role in embryonic development and cell cycle progression (4,5).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Western Blotting

Background: FAF1 was originally identified though yeast two-hybrid screening, interacting with the cytoplasmic domain of Fas, a member of the TNF receptor superfamily that plays a critical role in in apoptosis during development and immune function (1). FAF1 is widely expressed with highest expression observed in testis, skeletal muscle and heart (2). FAF1 potentiates Fas-mediated apoptosis and may induce apoptosis without Fas stimulation in some cell types. It does not contain typical death motifs, but rather has two amino-terminal domains with structural homology to ubiquitin. While the precise role of FAF1 during apoptosis is still unclear, it has been observed to be one of the components of the death-inducing signaling complex (DISC) during Fas-mediated apoptosis and can bind to caspase-8 and FADD (3). FAF1 has also been shown to suppress the activation of the NF-kappaB transcription factor (4).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Western Blotting

Background: FAIM (Fas apoptosis inhibitory molecule) was identified as a protein that was inducibly expressed in B lymphocytes resistant to Fas-mediated apoptosis (1). Expression of FAIM inhibits receptor-mediated apoptosis in B cells as well as other cell types (1-3). FAIM is expressed in germinal center B cells, is positively regulated by IRF-4, and is also capable of inducing IRF-4 expression in a feed-forward mechanism (4). FAIM also regulates T cell receptor-mediated apoptosis by modulating Akt activation and Nur77 expression (2). Knockout mice for FAIM show an increased sensitivity to Fas-mediated apoptosis within B and T cells as well as hepatocytes (5). An alternatively spliced form of FAIM, termed FAIM-L, is found predominantly in the brain (6). In the nervous system, the originally identified FAIM does not appear to play a role in apoptosis, but rather can promote neurite outgrowth through the activation of Erk and NF-κB pathways (7). In contrast, FAIM-L does inhibit neuronal cell death triggered by death receptors (3).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Western Blotting

Background: Association of the receptor Fas with its ligand FasL triggers an apoptotic pathway that plays an important role in immune regulation, development, and progression of cancers (1,2). Loss of function mutation in either Fas (lpr mice) or FasL (gld mice) leads to lymphadenopathy and splenomegaly as a result of decreased apoptosis in CD4-CD8- T lymphocytes (3,4). FasL (CD95L, Apo-1L) is a type II transmembrane protein of 280 amino acids (runs at approximately 40 kDa upon glycosylation) that belongs to the TNF family, which also includes TNF-α, TRAIL, and TWEAK. Binding of FasL to its receptor triggers the formation of a death-inducing signaling complex (DISC) involving the recruitment of the adaptor protein FADD and caspase-8 (5). Activation of caspase-8 from this complex initiates a caspase cascade resulting in the activation of caspase-3 and subsequent cleavage of proteins leading to apoptosis. Unlike Fas, which is constitutively expressed by various cell types, FasL is predominantly expressed on activated T lymphocytes, NK cells, and at immune privileged sites (6). FasL is also expressed in several tumor types as a mechanism to evade immune surveillance (7). Similar to other members of the TNF family, FasL can be cleaved by metalloproteinases producing a 26 kDa trimeric soluble form (8,9).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Immunoprecipitation, Western Blotting

Background: The gasdermin family that includes GSDMA, GSDMB, GSMDC, GSDMD, and GSDME have been shown to play a role in inflammation and cell death. Gasedermin D has been reported to have a critical role as a downstream effector of pyroptosis (1,2). Pyroptosis is a lytic type of cell death triggered by inflammasomes, multiprotein complexes assembled in response to pathogen-associated molecular patterns (PAMPs) or danger-associated molecular patterns (DAMPs) that result in the activation of caspase-1 and subsequent cleavage of pro-inflammatory cytokines IL-1β and IL-18 (3). Gasdermin D was identified by two independent groups as a substrate of inflammatory caspases, caspase-1 and caspase-11/4/5, producing two fragments: GSDMD-N and GSDMD-C. Cleavage results in release of an intramolecular inhibitory interaction between the N- and C-terminal domains, allowing the N-terminal fragment GSMDM-N to initiate pyroptosis through the formation of pores on the plasma membrane (4-7).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Western Blotting

Background: Gasdermin D (GSDMD), a member of the gasdermin family that includes GSDMA, GSDMB, and GSMDC, has been reported to have a critical role as a downstream effector of pyroptosis (1,2). Pyroptosis is a lytic type of cell death triggered by inflammasomes, multiprotein complexes assembled in response to pathogen-associated molecular patterns (PAMPs) or danger-associated molecular patterns (DAMPs) that result in the activation of caspase-1 and subsequent cleavage of pro-inflammatory cytokines IL-1β and IL-18 (3). Gasdermin D was identified by two independent groups as a substrate of inflammatory caspases, caspase-1 and caspase-11/4/5, producing two fragments: GSDMD-N and GSDMD-C. Cleavage results in release of an intramolecular inhibitory interaction between the N- and C-terminal domains, allowing the N-terminal fragment GSMDM-N to initiate pyroptosis through the formation of pores on the plasma membrane (4-7).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Peptide ELISA (DELFIA), Western Blotting

Background: Granzymes are a family of serine proteases expressed by cytotoxic T lymphocytes and natural killer (NK) cells and are key components of immune responses to pathogens and transformed cells (1). Granzymes are synthesized as zymogens and are processed into mature enzymes by cleavage of a leader sequence. They are released by exocytosis in lysosome-like granules containing perforin, a membrane pore-forming protein. Granzyme B has the strongest apoptotic activity of all the granzymes as a result of its caspase-like ability to cleave substrates at aspartic acid residues thereby activating procaspases directly and cleaving downstream caspase substrates (2,3).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse

Application Methods: Peptide ELISA (DELFIA), Western Blotting

Background: Granzymes are a family of serine proteases expressed by cytotoxic T lymphocytes and natural killer (NK) cells and are key components of immune responses to pathogens and transformed cells (1). Granzymes are synthesized as zymogens and are processed into mature enzymes by cleavage of a leader sequence. They are released by exocytosis in lysosome-like granules containing perforin, a membrane pore-forming protein. Granzyme B has the strongest apoptotic activity of all the granzymes as a result of its caspase-like ability to cleave substrates at aspartic acid residues thereby activating procaspases directly and cleaving downstream caspase substrates (2,3).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Western Blotting

Background: Members of the homeodomain-interacting protein kinase (HIPK1-4) family of serine/threonine kinases regulate gene transcription with effects on cell proliferation, differentiation, and apoptosis (1-3). HIPK1-3 are nuclear proteins that were originally described as co-repressors for homeobox transcription factors (1). HIPK proteins can interact with and/or phosphorylate many transcriptional regulators (4).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Monkey, Mouse, Rat

Application Methods: Western Blotting

Background: High temperature requirement protein A2 (HtrA2)/Omi is a serine protease with homology to the E. coli HtrA protein (DegP) and is thought to be involved in apoptosis and stress-induced degradation of misfolded proteins (1). While HtrA2 was orignally identified to be present in either the nucleus (1) or endoplasmic reticulum (2), subsequent studies have shown that it localizes in mitochondria and is released during apoptosis (3-8). HtrA2 is produced as a 50 kDa zymogen that is cleaved to generate a 36 kDa mature protein that exposes an amino terminal motif (AVPS) resembling that of the IAP inhibitor Smac/Diablo (3-8). Like Smac, interaction between HtrA2 and IAP family members, such as XIAP, antagonizes their inhibition of caspase activity and protection from apoptosis (3-8). Interestingly, HtrA2 knock-out mice did not show signs of reduced apoptosis, but rather had a loss of neurons in the striatum and a Parkinson's-like phenotype, suggesting that HtrA2 might have a neuroprotective function (9-11). This activity is associated with the protease activity of HtrA2 (9). Furthermore, research studies have shown that loss of function mutations in the HtrA2 gene are associated with Parkinson's disease (12).