Cytokine signaling mediated by the JAK-STAT pathway plays essential roles in differentiation, maturation, proliferation and apoptosis of a various types of cells. Suppressor of cytokine signaling (SOCS) proteins are negative feedback regulators of the JAK-STAT signaling pathway. SOCS1 and SOCS3 are potent inhibitors of JAKs and can play pivotal roles in inflammation, as well as in the development and progression of cancers . All SOCS share a central SH2 domain and a C-terminal SOCS box, but only SOCS1 and SOCS3 possess a kinase inhibitory region immediately upstream of the central SH2 .

suppressor of cytokine signaling 6 Predicted to enable signaling adaptor activity. Acts upstream of or within proteasomal protein catabolic process. Located in immunological synapse. The protein encoded by this gene contains a SH2 domain and a CIS homolog domain. The protein thus belongs to the cytokine-induced STAT inhibitor (CIS), also known as suppressor of cytokine signaling (SOCS) or STAT-induced STAT inhibitor (SSI), protein family. CIS family members are known to be cytokine-inducible negative regulators of cytokine signaling. The expression of this gene can be induced by GM-CSF and EPO in hematopoietic cells. A high expression level of this gene was found in factor-independent chronic myelogenous leukemia (CML) and erythroleukemia (HEL) cell lines. [provided by RefSeq, Jul 2008]

Suppressors of cytokine signaling-3 (SOCS3) is associated with limitations of nerve growth capacity after injury to the central nervous system. Although genetic manipulations of SOCS3 can enhance axonal regeneration after optic injury, the role of SOCS3 in dendritic outgrowth after spinal cord injury (SCI) is still unclear. The present study investigated the endogenous expression of SOCS3 and its role in regulating neurite outgrowth in vitro. Interleukin-6 (IL-6) induces SOCS3 expression at the mRNA and protein levels in neuroscreen-1 (NS-1) cells. In parallel to SOCS3 expression, IL-6 induced tyrosine phosphorylation of signal transducer and activator of transcription 3 (STAT3) in NS-1 cells. Lentiviral delivery of short hairpin RNA (shSOCS3) (Lenti-shSOCS3) to decrease SOCS3 expression into NS-1 cells enhanced IL-6-induced tyrosine phosphorylation of STAT3 (P-STAT3 Tyr705) and promoted neurite outgrowth. In addition, we determined if reduction of SOCS3 expression by microinjection of Lenti-shSOCS3 into spinal cord enhances dendrite outgrowth in spinal cord neurons after SCI. Knocking down of SOCS3 in spinal cord neurons with Lenti-shSOCS3 increased complete SCI-induced P-STAT3 Tyr705. Immunohistochemical analysis showed that complete SCI induced a significant reduction of microtubule association protein 2-positive (MAP-2+) dendrites in the gray and white matter at 1 and 4 weeks after injury. The SCI-induced reduction of MAP-2+ dendrites was inhibited by infection with Lenti-shSOCS3 in areas both rostral and caudal to the lesion at 1 and 4 weeks after complete SCI. Furthermore, shSOCS3 treatment enhanced up-regulation of growth associated protein-43 (GAP-43) expression, which co-localized with MAP-2+ dendrites in white matter and with MAP-2+ cell bodies in gray matter, indicating Lenti-shSOCS3 may induce dendritic regeneration after SCI. Moreover, we demonstrated that Lenti-shSOCS3 decreased SCI-induced demyelination in white matter of spinal cord both rostral and caudal to the injury site 1 week post-injury, but not rostral to the injury at 4 weeks post-injury. Importantly, similar effects as Lenti-shSOCS3 on increasing MAP-2+ intensity and dendrite length, and preventing demyelination were observed when a second shSOCS3 (Lenti-shSOCS3 #2) was applied to rule out the possibilities of off target effects of shRNA. Collectively, these results suggest that knocking down of SOCS3 enhances dendritic regeneration and prevents demyelination after SCI.

Sepsis is one of the major causes of human morbidity and results in a considerable number of deaths each year. Lipopolysaccharide-induced sepsis has been associated with TLR4 signalling pathway which in collaboration with the JAK/STAT signalling regulate endotoxemia and inflammation. However, during sepsis our immune system cannot maintain a balance of cytokine levels and results in multiple organ damage and eventual death. Different opinions have been made in previous studies about the expression patterns and the role of proinflammatory cytokines in sepsis that attracted our attention towards qualitative properties of TLR4 and JAK/STAT signalling pathways using computer-aided studies. René Thomas’ formalism was used to model septic and non-septic dynamics of TLR4 and JAK/STAT signalling. Comparisons among dynamics were made by intervening or removing the specific interactions among entities. Among our predictions, recurrent induction of proinflammatory cytokines with subsequent downregulation was found as the basic characteristic of septic model. This characteristic was found in agreement with previous experimental studies, which implicate that inflammation is followed by immunomodulation in septic patients. Moreover, intervention in downregulation of proinflammatory cytokines by SOCS-1 was found desirable to boost the immune responses. On the other hand, interventions either in TLR4 or transcriptional elements such as NFκB and STAT were found effective in the downregulation of immune responses. Whereas, IFN-β and SOCS-1 mediated downregulation at different levels of signalling were found to be associated with variations in the levels of proinflammatory cytokines. However, these predictions need to be further validated using wet laboratory experimental studies to further explore the roles of inhibitors such as SOCS-1 and IFN-β, which may alter the levels of proinflammatory cytokines at different stages of sepsis.

suppressor of cytokine signaling 2 Enables insulin-like growth factor receptor binding activity; phosphorylation-dependent protein binding activity; and ubiquitin-like ligase-substrate adaptor activity. Involved in several processes, including growth hormone receptor signaling pathway; negative regulation of growth hormone receptor signaling pathway; and response to estradiol. Part of Cul5-RING ubiquitin ligase complex. Is active in cytoplasm. Implicated in endometrial cancer and ovarian carcinoma. Biomarker of ductal carcinoma in situ and invasive ductal carcinoma. This gene encodes a member of the suppressor of cytokine signaling (SOCS) family. SOCS family members are cytokine-inducible negative regulators of cytokine receptor signaling via the Janus kinase/signal transducer and activation of transcription pathway (the JAK/STAT pathway). SOCS family proteins interact with major molecules of signaling complexes to block further signal transduction, in part, by proteasomal depletion of receptors or signal-transducing proteins via ubiquitination. The expression of this gene can be induced by a subset of cytokines, including erythropoietin, GM-CSF, IL10, interferon (IFN)-gamma and by cytokine receptors such as growth horomone receptor. The protein encoded by this gene interacts with the cytoplasmic domain of insulin-like growth factor-1 receptor (IGF1R) and is thought to be involved in the regulation of IGF1R mediated cell signaling. This gene has pseudogenes on chromosomes 20 and 22. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jul 2012]

Suppressors of cytokine signalling (SOCS) proteins are classic inhibitors of the Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway. Many cytokines and pathogenic mediators induce expression of SOCS, which act in a negative feedback loop to inhibit further signal transduction. SOCS mRNA expression is regulated by DNA binding of STAT proteins, however, their post-transcriptional regulation is poorly understood. microRNAs (miRNAs) are small non-coding RNAs that bind to complementary sequences on target mRNAs, often silencing gene expression. miR-19a has been shown to regulate SOCS1 expression during mutiple myeloma and be induced by the anti-viral cytokine interferon-(IFN)-α, suggesting a role in the regulation of the JAK-STAT pathway. This study aimed to identify targets of miR-19a in the JAK-STAT pathway and elucidate the functional consequences. Bioinformatic analysis identified highly conserved 3’UTR miR-19a target sequences in several JAK-STAT associated genes, including SOCS1, SOCS3, SOCS5 and Cullin (Cul) 5. Functional studies revealed that miR-19a significantly decreased SOCS3 mRNA and protein, while a miR-19a antagomir specifically reversed its inhibitory effect. Furthermore, miR-19a-mediated reduction of SOCS3 enhanced IFN-α and interleukin (IL)-6 signal transduction through STAT3. These results reveal a novel mechanism by which miR-19a may augment JAK-STAT signal transduction via control of SOCS3 expression and are fundamental to the understanding of inflammatory regulation.

Protein-Protein, Genetic, and Chemical Interactions for Ben-Zvi T (2006):Suppressors of cytokine signaling (SOCS) 1 and SOCS3 interact with and modulate fibroblast growth factor receptor signaling. curated by BioGRID (https://thebiogrid.org); ABSTRACT: Fibroblast growth factor receptor (FGFR) signaling is transduced by the mitogen-activated protein kinase (MAPK) cascade and the signal transducers and activators of transcription (STATs). Suppressors of cytokine signaling (SOCS) proteins are expressed in response to cytokine-inducible stimulation of STAT phosphorylation, acting in a negative-feedback mechanism to hinder the activities of these receptors. However, there are no data concerning the role of SOCS proteins in the regulation of fibroblast growth factor receptor (FGFR) signaling. In the present study, we show that activation of FGFR in chondrocytes induces the expression of SOCS1 and SOCS3 mRNA, and that these proteins are constitutively associated with FGFR3, as demonstrated by co-immunoprecipitation studies. Transfection of cells with FGFR3-GFP and SOCS1-CFP revealed their colocalization, clustered prominently in the perinuclear cytosolic part of the cell. The effect of the interaction between FGFR3 and SOCS1 on receptor activity was investigated in a chondrocytic cell line overexpressing SOCS1. In these cells, STAT1 phosphorylation is repressed, MAPK phosphorylation is elevated and prolonged, and FGFR3 downregulation is attenuated. Expression of osteopontin (OPN), which is directly upregulated by FGF in chondrocytes, was stimulated by lower levels of FGF in cells expressing SOCS1 compared with parental cells. Blocking of MAPK phosphorylation by PD98059 decreased OPN expression in both cell types, but this decrease was more marked in cells expressing SOCS1. The presented results suggest a novel interaction between the SOCS1 and SOCS3 proteins and the FGFR3 signaling pathway.

The protein encoded by this gene contains a SH2 domain and a SOCS BOX domain. The protein thus belongs to the suppressor of cytokine signaling (SOCS) family, also known as STAT-induced STAT inhibitor (SSI) protein family. SOCS family members are known to be cytokine-inducible negative regulators of cytokine signaling. The specific function of this protein has not yet been determined. Two alternatively spliced transcript variants encoding an identical protein have been reported. [provided by RefSeq, Jul 2008]

suppressor of cytokine signaling 1 Enables kinase inhibitor activity. Involved in negative regulation of CD8-positive, alpha-beta T cell differentiation and positive regulation of CD4-positive, alpha-beta T cell differentiation. Acts upstream of or within several processes, including cell surface receptor signaling pathway; fat cell differentiation; and negative regulation of signal transduction. Predicted to be located in nucleoplasm. Is expressed in several structures, including adipose tissue; genitourinary system; gut; hemolymphoid system gland; and nervous system. Human ortholog(s) of this gene implicated in acute myeloid leukemia; gastrointestinal system cancer (multiple); reproductive organ cancer (multiple); and urinary bladder cancer. Orthologous to human SOCS1 (suppressor of cytokine signaling 1). PHENOTYPE: Homozygotes for targeted null mutations exhibit retarded growth, hyperresponsiveness to endogenous interferon gamma, hepatitis with fatty degeneration, lymphopenia due to excess apoptosis, monocytic organ infiltration, and lethality by 3 weeks of age. [provided by MGI curators]

Protein-Protein, Genetic, and Chemical Interactions for Niwa Y (2005):Methylation silencing of SOCS-3 promotes cell growth and migration by enhancing JAK/STAT and FAK signalings in human hepatocellular carcinoma. curated by BioGRID (https://thebiogrid.org); ABSTRACT: We identified that suppressor of cytokine signaling-3 (SOCS-3) gene was aberrantly methylated in its CpG island in three of 10 human hepatocellular carcinoma (HCC) cell lines. SOCS-3 RNA was undetectable in five of the 10 HCC cell lines including the three methylated cell lines, and a demethylating agent, 5-aza-2'-deoxycytidine, reactivated SOCS-3 expression in three cell lines tested. The DNA region where we found aberrant DNA methylation includes a signal transducers and activators of transcription (STAT) binding consensus sequence. When the DNA region was used as a promoter, DNA methylation markedly reduced promoter activity. SOCS-3 was also aberrantly methylated in six of 18 primary HCC samples. SOCS-3 expression was reduced in three of the three methylated and one of the three unmethylated primary samples examined. Restoration of SOCS-3 in cells lacking SOCS-3 expression suppressed STAT3 phosphorylation and cell growth. We found that IL-6 acted as a growth factor in HCC cells. Inhibition of SOCS-3 expression in cells whose growth was induced by IL-6 enhanced STAT3 phosphorylation and cell growth. In addition, AG490, a chemical JAK2 inhibitor, suppressed cell growth and downregulated STAT3 phosphorylation, but not FAK phosphorylation. We also found that SOCS-3 physically interacted with phosphorylated FAK and Elongin B in HCC cells. Restoration of SOCS-3 decreased FAK phosphorylation as well as FAK protein level. Inhibition of SOCS-3 expression increased FAK phosphorylation, resulting in enhancement of cell migration. These data indicate that SOCS-3 negatively regulates cell growth and cell motility by inhibiting Janus kinase (JAK)/STAT and FAK signalings in HCC cells. Thus, loss of SOCS-3 by the associated DNA methylation confers cells advantage in growth and migration.

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The protein encoded by this gene contains a SH2 domain and a SOCS BOX domain. The protein thus belongs to the suppressor of cytokine signaling (SOCS), also known as STAT-induced STAT inhibitor (SSI), protein family. SOCS family members are known to be cytokine-inducible negative regulators of cytokine signaling. Two alternatively spliced transcript variants encoding the same protein have been found for this gene. [provided by RefSeq, Jul 2008]

Corticotroph SOCS-3 as an intracellular suppressor of cytokine signaling. Corticotroph SOCS-3 inhibits STAT-dependent POMC gene expression by negatively interfering with LIF-induced activation of the JAK-STAT cascade. In contrast, CRH-induced POMC gene expression is not affected by SOCS-3. LIF stimulation of the corticotroph results in rapid upregulation of SOCS-3 by a STAT-dependent mechanism. Thus, LIF-induced activation of corticotroph POMC gene activation is limited by parallel induction of SOCS-3 expression, rendering the cell resistant to further JAK-STAT activation. On the other hand, autoregulation of STAT-dependent SOCS-3 gene expression and rapid degradation of SOCS-3 protein by the proteasome pathway enable the cell to restore its functional status. LIF and CRH synergistically induce POMC promoter activity. LIF activates POMC promoter activity not only by direct binding of activated STATs, but also indirectly by inducing STAT-dependent expression of transcription factors c-fos and JunB. CRH also induces SOCS3 promoter activity by binding of c-fos and JunB. Thus, CRH indirectly inhibits LIF-induced POMC promoter activation and downregulates the synergistic cross-talk of CRH and LIF on POMC promoter activity. Adapted from ref. and ref. with permission.

Protein-Protein, Genetic, and Chemical Interactions for Dey BR (2000):Suppressor of cytokine signaling (SOCS)-3 protein interacts with the insulin-like growth factor-I receptor. curated by BioGRID (https://thebiogrid.org); ABSTRACT: SOCS proteins are a class of proteins that are negative regulators of cytokine receptor signaling via the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway. In a yeast two-hybrid screen of a human fetal brain library, we have previously identified SOCS-2 as a binding partner of the activated IGF-I receptor (IGFIR). To test whether or not SOCS-3 also binds to the IGFIR, we cloned human SOCS-3 by reverse transcription-polymerase chain reaction from human skeletal muscle mRNA. SOCS-3 mRNA was expressed in many human fetal and adult tissues and in some human cancer cell lines (Hela, A549 pulmonary adenocarcinoma and G361 human melanoma). We found that human SOCS-3 protein interacts directly with the cytoplasmic domains of the activated IGFIR and the insulin receptor (IR) in the yeast two-hybrid assay. In GST-SOCS-3 pull-down experiments using IGFIR from mammalian cells and in immunoprecipitation experiments in which IGFIR and FLAG-SOCS-3 were transiently expressed in human embryonic kidney 293 cells, we found that SOCS-3 interacts constitutively with IGFIR in vitro and in intact cells. Unlike SOCS-2, hSOCS-3 was phosphorylated on tyrosines in response to IGF-I addition to 293 cells. We conclude that SOCS-3 binds to the IGFIR and may be a direct substrate for the receptor tyrosine kinase.

suppressor of cytokine signaling 3 Enables protein tyrosine kinase inhibitor activity. Involved in negative regulation of receptor signaling pathway via JAK-STAT. Is active in cytoplasmic side of plasma membrane. Implicated in obesity. Biomarker of several diseases, including ductal carcinoma in situ; human immunodeficiency virus infectious disease; invasive ductal carcinoma; obesity; and type 2 diabetes mellitus. This gene encodes a member of the STAT-induced STAT inhibitor (SSI), also known as suppressor of cytokine signaling (SOCS), family. SSI family members are cytokine-inducible negative regulators of cytokine signaling. The expression of this gene is induced by various cytokines, including IL6, IL10, and interferon (IFN)-gamma. The protein encoded by this gene can bind to JAK2 kinase, and inhibit the activity of JAK2 kinase. Studies of the mouse counterpart of this gene suggested the roles of this gene in the negative regulation of fetal liver hematopoiesis, and placental development. [provided by RefSeq, Jul 2008]

Protein-Protein, Genetic, and Chemical Interactions for Chen XP (2002):Pim serine/threonine kinases regulate the stability of Socs-1 protein. curated by BioGRID (https://thebiogrid.org); ABSTRACT: Studies of SOCS-1-deficient mice have implicated Socs-1 in the suppression of JAK-STAT (Janus tyrosine kinase-signal transducers and activators of transcription) signaling and T cell development. It has been suggested that the levels of Socs-1 protein may be regulated through the proteasome pathway. Here we show that Socs-1 interacts with members of the Pim family of serine/threonine kinases in thymocytes. Coexpression of the Pim kinases with Socs-1 results in phosphorylation and stabilization of the Socs-1 protein. The protein levels of Socs-1 are significantly reduced in the Pim-1(-/-), Pim-2(-/-) mice as compared with wild-type mice. Similar to Socs-1(-/-) mice, thymocytes from Pim-1(-/-), Pim-2(-/-) mice showed prolonged Stat6 phosphorylation upon IL-4 stimulation. These data suggest that the Pim kinases may regulate cytokine-induced JAK-STAT signaling through modulation of Socs-1 protein levels.

Regulatory pathways in hepcidin expression. In the BMP/Smad pathway, the binding of BMPs to the BMP receptor induces receptor regulated Smads (R-Smads); following phosphorylation, R-Smads heterodimerize with Smad 4 (common Smad) and co-migrate to the nucleus where they bind to the BMP response elements (BMP-RE) in the hepcidin promoter. R-Smads can be inhibited by inhibitory Smads (I-Smads). An iron sensor complex which may include HFE, TfR2, HJV and TMPRSS6, is regulated by transferrin-bound iron (Tf-Fe). This (hypothetical) complex transmits iron signals via ERK1/2 for activation of a putative iron-responsive transcription factor which binds to the hepcidin promoter or modulates Smad phosphorylation and influences levels of hepcidin expression. Homo- and/or heterodimers of USF1/USF2 compete with HIF-1 for binding to the E-boxes; the signals for this may be generated by the iron sensor complex. The inflammatory (JAK-STAT) pathway engages IL-6 and its receptor, causing phosphorylation of the Janus kinase; this phosphorylates STAT3 which subsequently forms homodimers and translocates to the nucleus where they bind to the interferon γ-activation sequence (GAS) on the hepcidin promoter to drive transcription. The C/EBPs may also be regulated by this pathway (shown with a stippled arrow). The JAK-STAT pathway can be inhibited by the suppressors of cytokine signaling (SOCS), phosphotyrosine phosphatases (SHPS) and PIAS (Protein Inhibitor of Activated STAT). Both the SOCS and SHPs are induced by IL-6 but inhibit JAK-STAT signaling in a negative feed-back loop.

Protein-Protein, Genetic, and Chemical Interactions for Ghazawi FM (2016):Suppressor of cytokine signaling (SOCS) proteins are induced by IL-7 and target surface CD127 protein for degradation in human CD8 T cells. curated by BioGRID (https://thebiogrid.org); ABSTRACT: Given the essential role interleukin (IL)-7 plays in T-cell survival, homeostasis and function, it is no surprise expression of the IL-7 receptor alpha-chain (CD127) is tightly regulated. We have previously shown IL-7 binding to its receptor on the surface of CD8 T cells leads to both suppression of CD127 gene transcription and loss of existing CD127 protein from the cell membrane. Indeed upon binding IL-7, CD127 is rapidly internalized into early endosomes where phosphorylation by JAK targets the receptor for degradation. We now show that IL-7 induces the expression of suppressor of cytokine signaling (SOCS) proteins CIS, SOCS1 and SOCS2 through the JAK/STAT-5 pathway and that CIS and SOCS2 specifically interact with CD127 in early endosomes and direct the receptor complex to the proteasome for degradation. These results illustrate how expression of the IL-7 receptor and thus IL-7 signaling is modulated in human CD8 T cells by a negative feedback mechanism dependent on members of the SOCS family of proteins.

Rainbow trout oligonucleotides used in this study.

The System-on-Chip (SoC) market for IP cameras has become a critical component in the evolving landscape of security and surveillance technology. SoCs serve as the brain of IP cameras, integrating various functionalities such as image processing, compression, and transmission within a single chip. This innovation no