Product Pathways - Jak/Stat Pathway

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Jak/Stat Pathway Inhibitors Antibody Sampler Kit #8343

Kit Includes	Quantity	Applications	Reactivity	MW (kDa)	Isotype
SOCS1 (A156) Antibody #3950	40 µl	W	H M R Mk (Dg)	23	Rabbit
SOCS2 Antibody #2779	40 µl	W IP	H M R	22	Rabbit
SOCS3 (L210) Antibody #2932	40 µl	W	H M R (Mk) (B) (Dg)	26	Rabbit
PIAS1 (D33A7) XP® Rabbit mAb #3550	40 µl	W IF-IC F	H M R Mk	76	Rabbit IgG
PIAS3 Antibody #4164	40 µl	W	H M R Mk	65-75	Rabbit
PIAS4 (D2F12) Rabbit mAb #4392	40 µl	W IP	H R Mk (M)	75	Rabbit IgG
Anti-rabbit IgG, HRP-linked Antibody #7074	100 µl				Goat

Applications Key:  W=Western Blotting  IP=Immunoprecipitation  IF-IC=Immunofluorescence (Immunocytochemistry)  F=Flow Cytometry
Reactivity Key:  H=Human  M=Mouse  R=Rat  Mk=Monkey  B=Bovine  Dg=Dog
Species enclosed in parentheses are predicted to react based on 100% sequence homology.

Specificity / Sensitivity

Each antibody in this kit recognizes only the specific target protein and does not cross-react with other family members.

Description

The Jak/Stat Pathway Inhibitors Antibody Sampler Kit provides an economical means to examine several inhibitors of Jak/Stat signaling, including PIAS1, PIAS3, PIAS4, SOCS1, SOCS2, and SOCS3. The kit contains enough primary antibody to perform four western blot experiments with each primary antibody.

Source / Purification

Polyclonal antibodies are produced by immunizing animals with a synthetic peptide corresponding to residues surrounding Thr585 of human PIAS3 protein, residues surrounding Ala156 of human SOCS1 protein, residues at the carboxy terminus of human SOCS2 protein, or residues surrounding Leu210 of human SOCS3 protein. Polyclonal antibodies are purified by protein A and peptide affinity chromatography. Monoclonal antibodies are produced by immunizing animals with a synthetic peptide corresponding to residues surrounding Ser550 of human PIAS1 protein or Lys59 of human PIAS4 protein.

Background

Jak (Janus Kinase) and Stat (signal transducer and activator of transcription) proteins are utilized by receptors for a wide varity of ligands including cytokines, hormones, growth factors, and neurotransmitters (1). Jaks and Stats play important roles in oncogenesis, tumor progression, angiogenesis, cell motility, immune responses, and stem cell differentiation (2-5). Therefore, regulation of Jak/Stat signaling is crucial to prevent aberrant signaling which can lead to disease progression. Two methods for regulating Jak/Stat signaling involve SOCS and PIAS proteins (6,7).The SOCS (suppressor or cytokine signaling) family members are negative regulators of cytokine signal transduction that inhibit the Jak/Stat pathway and consist of 8 known members, including the originally identified protein CIS1 (cytokine-inducible SH2-containing protein) and SOCS1-SOCS7. Each SOCS family member contains a central SH2 domain and a conserved carboxy-terminal motif designated as the SOCS box. These proteins are important regulators of cytokine signaling, proliferation, differentiation, and immune responses (8-10). SOCS proteins are involved in regulating over 30 cytokines, including interleukins, growth hormone (GH), interferons, leptin, and leukemia inhibitory factor (7). SOCS1, also known as JAB (Janus Kinase binding protein) and SSI-1 (Stat-induced Stat inhibitor-1), shares the most homology with SOCS3 and both are highly induced by cytokines (7,11). Both SOCS1 and SOCS3 directly inhibit Jak activity; SOCS1 inhibits Jak through an interaction involving a phospohotyrosine located in the kinase activation loop; SOCS3 inhibits Jak via its SH2 domain (12,13). In addition to inhibiting Jak/Stat signaling, the SOCS box of SOCS1 and SOCS3 can trigger ubiquitin-mediated degradation of proteins within and outside the Jak/Stat pathway (14,15). SOCS2 is also incduced upon cytokine stimulation and the activity of SOCS2 has been predominately linked to GH and insulin-like growth factor signaling by binding to tyrosine-phosphorylated receptors via its SH2 domain (11,16).The PIAS (protein inhibitor of activated Stats) proteins, which include PIAS1, PIAS3, PIASx, and PIASy (PIAS4), were originally characterized based on their interaction with the Stat family of transcription factors (16,17). PIAS1, PIAS3, and PIASx interact with and repress Stat1, Stat3, and Stat4, respectively (17-19). The PIAS family contains a conserved RING domain that has been linked to function as a SUMO (small ubiquitin-related modifer) ligase, coupling the SUMO conjugating enzyme Ubc9 with its substrate proteins leading to regulation of transcription factors through distinct mechanisms including NF-κB, c-Jun, Oct-4, p53, and SMADs. PIAS4 is a specific SUMO-E3 ligase for Ets-1 and represses Ets-1 dependent transcription in addition to altering the nuclear localization and reducing the transcriptional activity of C/EBPδ, thereby enhancing cell proliferation and migration (20,21).

1. Darnell, J.E. et al. (1994) Science 264, 1415-21.
2. Bromberg, J.F. et al. (1999) Cell 98, 295-303.
3. Dentelli, P. et al. (1999) J Immunol 163, 2151-9.
4. Cattaneo, E. et al. (1999) Trends Neurosci 22, 365-9.
5. Su, L. et al. (1999) J Biol Chem 274, 31770-4.
6. Shuai, K. (2006) Cell Res 16, 196-202.
7. Croker, B.A. et al. (2008) Semin Cell Dev Biol 19, 414-22.
8. Alexander, W.S. et al. (1999) J Leukoc Biol 66, 588-92.
9. Chen, X.P. et al. (2000) Immunity 13, 287-90.
10. Hilton, D.J. et al. (1998) Proc Natl Acad Sci U S A 95, 114-9.
11. Starr, R. et al. (1997) Nature 387, 917-21.
12. Yasukawa, H. et al. (1999) EMBO J 18, 1309-20.
13. Sasaki, A. et al. (1999) Genes Cells 4, 339-51.
14. Kamizono, S. et al. (2001) J Biol Chem 276, 12530-8.
15. Rui, L. et al. (2002) J Biol Chem 277, 42394-8.
16. Dey, B.R. et al. (1998) J Biol Chem 273, 24095-101.
17. Liu, B. et al. (1998) Proc Natl Acad Sci U S A 95, 10626-31.
18. Chung, C.D. et al. (1997) Science 278, 1803-5.
19. Arora, T. et al. (2003) J Biol Chem 278, 21327-30.
20. Nishida, T. et al. (2007) Biochem J 405, 481-8.
21. Zhou, S. et al. (2008) J Biol Chem 283, 20137-48.

Application References

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Protocols

2779:

Immunoprecipitation, Western Blotting

2932:

Western Blotting

3550:

Flow, Immunofluorescence, Western Blotting

3950:

Western Blotting

4164:

Western Blotting

4392:

Immunoprecipitation, Western Blotting

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For Research Use Only. Not For Use In Diagnostic Procedures.