CIS, a Cytokine Inducible SH2 Protein, Is a Target of the JAK-STAT5 Pathway and Modulates STAT5 Activation

Abstract

We searched for immediate early cytokine responsive genes and isolated a novel gene, CIS (Cytokine Inducible SH2 containing protein) that is induced in hematopoietic cells by a subset of cytokines including interleukin-2 (IL-2), IL-3, and erythropoietin (EPO). The mutant IL-2 receptor that fails to activate STAT5 could not induce CIS, suggesting that STAT5 is involved in the cytokine-inducible expression of CIS. We cloned the 5′-flanking region of the CIS gene and found that about 200 bases upstream of the transcription-initiation site contain four potential STAT5 binding sites (MGF boxes). Luciferase reporter assays showed that these MGF boxes were essential for EPO-dependent promoter activity. Expression of STAT5 and the EPO receptor in HEK293 cells conferred EPO-dependent activation of the CIS promoter. These data indicate that CIS is a target of the JAK-STAT5 pathway of cytokine receptors. CIS contains an SH2 domain and binds to tyrosine-phosphorylated EPO and IL-3 receptors. In HEK293 cells expressing STAT5 and the EPO receptor, EPO-dependent tyrosine phosphorylation of STAT5, as well as EPO-dependent CIS-promoter activation, was suppressed when CIS was coexpressed. Moreover, the induction of oncostatin M, another STAT5 target, as well as the tyrosine-phosphorylation of STAT5, were partially suppressed by CIS expression in Ba/F3 cells. Thus, CIS is a feedback modulator of STAT5; its expression is induced by STAT5 and it negatively modulates STAT5 activation.

Mutational analyses of the SOCS proteins suggest a dual domain requirement but distinct mechanisms for inhibition of LIF and IL-6 signal transduction

“…It has also been demonstrated to inhibit TEC tyrosine kinase activity (Ohya et al, 1997), suggesting that its spectrum of activity may extend beyond that of the JAK family. There is some evidence that transcription of the SOCS-1 gene is regulated by Stat3 (Naka et al, 1997) in a manner similar to the transcriptional regulation of CIS by Stat5 (Matsumoto et al, 1997). The initial data therefore suggest that SOCS-1, at least, is part of a classical negative feedback loop.…”

Cytokine‐inducible SH2 protein‐3 (CIS3/SOCS3) inhibits Janus tyrosine kinase by binding through the N‐terminal kinase inhibitory region as well as SH2 domain

“…The first member of this family (CIS1) was cloned as an immediate early gene induced by a number of cytokines including erythropoietin (EPO), IL-2, IL-3 and granulocyte macrophage-colony stimulating factor (GM-CSF) (Yoshimura et al 1995), and is regulated by STAT5 . CIS1 tightly binds tyrosine phosphorylated IL-3 and EPO receptors, and negatively regulates their signals when over-expressed (Yoshimura et al 1995;Matsumoto et al 1997). The second family member was independently cloned by three groups and is termed JAB, SOCS-1 or SSI-1 (Endo et al 1997;Naka et al 1997;Starr et al 1997).…”

Suppressors of cytokine signaling: Potential immune checkpoint molecules for cancer immunotherapy

“…(5) IL-2/STAT5 is also essential for regulatory T cell (Treg) development, and IL-21/STAT3 is essential for follicular helper T (Tfh) cell differentiation, (6) and regulates CD8 + T cells. (7) The CIS/SOCS Family: Molecular Mechanisms Suppressors of cytokine signaling proteins and cytokine inducible SH2-containing (CIS, also known as CISH) protein compose a family of intracellular proteins (8)(9)(10)(11)(12) (Fig. 2).…”

“…CIS was discovered as an inducible gene in response to various cytokines including EPO, IL-2, IL-3, and IL-5, which mostly activate STAT5. (10,11) CIS does not possess the KIR and cannot inhibit JAK tyrosine kinase activity directly. However, CIS binds to phosphorylated cytokines receptors, such as the EPO receptor, IL-2 receptor, IL-3 receptor b chain, prolactin receptor, and the growth hormone (GH) receptor, which mostly activate STAT5.…”

“…However, CIS binds to phosphorylated cytokines receptors, such as the EPO receptor, IL-2 receptor, IL-3 receptor b chain, prolactin receptor, and the growth hormone (GH) receptor, which mostly activate STAT5. (10,11,(21)(22)(23) Thus, CIS is believed to suppress STAT5 by masking STAT5-binding phosphotyrosine motifs on the receptors, and also by inducing ubiquitin/proteasome-dependent degradation of the activated receptors (24,25) (Fig. 3).…”