Siva-1 (Apoptosis Regulatory Protein Siva, SIVA)

First identified as a pro-apoptotic protein that binds the cytoplasmic tail of the TNF receptor superfamily member CD27 (1), Siva-1 also binds several other TNFR family members including glucocorticoid-induced tumor necrosis factor receptor (GITR) and OX40 (1-3), as well as anti-apoptotic Bcl-2 family members Bcl-xL and Bcl-2 (4,5). Siva-1 is composed of a central death domain homology region, a C-terminal box-B-like ring finger followed by a zinc finger-like domain, and a unique N-terminal amphipathic helical region (SAH) (1,4). Studies have demonstrated that Siva-1 has the ability to induce cell death via both the extrinsic and intrinsic apoptotic pathways (1-8). The SAH domain of Siva-1 is responsible for the inhibition of the pro-survival activities of Bcl-xL and Bcl-2, leading to caspase-mediated cell death (4,5,8). Siva-1 plays a role in T cell signaling and homeostasis by inhibiting NF-kB activity, also resulting in apoptotic cell death (7,9). An alternative splice variant of Siva-1, Siva-2, lacks part of the SAH and death domains and is less effective at inducing apoptosis (1,2,5,8). Studies in xenografts have shown that down-regulation of Siva-1 inhibits tumorigenesis in response to p53 activation (10). Down-regulation of Siva-1 may also play a role in tumor metastasis through its regulation of the epithelial-mesenchymal transition (EMT) and cell migration (11). Overexpression of Siva-1 is implicated in several pathological conditions including acute ischemic injury (12) and Coxsackievirus infection (13).\n\nApplications: \nSuitable for use in Western Blot and Immunoprecipitation. Other applications not tested.\n\nRecommended Dilution:\nWestern Blot: 1:1000. Incubate membrane with diluted antibody in 5% w/v BSA, 1X TBS, 0.1% Tween-20 at 4 degrees C with gentle shaking, overnight.\nImmunoprecipitation: 1:50\nOptimal dilutions to be determined by the researcher.\n\nStorage and Stability:\nMay be stored at 4 degrees C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20 degrees C. Aliquots are stable for 12 months. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.

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SPECIFICATIONS

Catalog Number

137491

Size

100ul

Applications

IP, WB

Hosts

Rabbit

Reactivities

Hum

Form

Supplied in 10mM sodium HEPES, pH 7.5, 150mM NaCl, 100ug/ml BSA and 50% glycerol.

P Type

Pab

Purity

Purified by Protein A affinity chromatography.

Isotype

IgG

References

1. Prasad, K.V. et al. (1997) Proc Natl Acad Sci U S A 94, 6346-51. 2. Yoon, Y. et al. (1999) Oncogene 18, 7174-9. 3. Spinicelli, S. et al. (2002) Cell Death Differ 9, 1382-4. 4. Xue, L. et al. (2002) Proc Natl Acad Sci U S A 99, 6925-30. 5. Chu, F. et al. (2004) Apoptosis 9, 83-95. 6. Cao, C. et al. (2001) J Biol Chem 276, 11465-8. 7. Gudi, R. et al. (2006) Oncogene 25, 3458-62. 8. Py, B. et al. (2004) J Immunol 172, 4008-17. 9. Hench, V.K. and Su, L. (2011) BMC Immunol 12, 54. 10. Du, W. et al. (2009) Cell Death Differ 16, 1493-504. 11. Li, N. et al. (2011) Proc Natl Acad Sci U S A 108, 12851-6. 12. Padanilam, B.J. et al. (1998) Kidney Int 54, 1967-75. 13. Henke, A. et al. (2000) J Virol 74, 4284-90.

Additional Info

Recognizes endogenous levels of total human Siva-1. Reacts with a protein of unknown origin at ~70kD. Does not cross-react with Siva-2.