Minimal Interleukin 6 (IL-6) Receptor Stalk Composition for IL-6 Receptor Shedding and IL-6 Classic Signaling

Baran, Paul; Nitz, Rebecca; Grötzinger, Joachim; Scheller, Jürgen; Garbers, Christoph

doi:10.1074/jbc.m113.466169

Cited by 70 publications

(83 citation statements)

References 39 publications

(47 reference statements)

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“…To investigate this, we made use of Ba/F3-gp130-hIL-6R cells. Ba/F3-gp130-hIL-6R cells are stably transduced with gp130 and the human (h) IL-6R, a well established substrate of ADAM10 and ADAM17 (20,21), but express neither protein endogenously. Stimulation with PMA resulted again in sgp130 formation (Fig.…”

Section: Gp130 Can Be Shed By Adam10 and Adam17 Albeit Withmentioning

confidence: 99%

Different Soluble Forms of the Interleukin-6 Family Signal Transducer gp130 Fine-tune the Blockade of Interleukin-6 Trans-signaling

Wolf

Waetzig

Chalaris

et al. 2016

Journal of Biological Chemistry

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Soluble forms of the IL-6 receptor (sIL-6R) bind to the cytokine IL-6 with similar affinity as the membrane-bound IL-6R. IL-6⅐sIL-6R complexes initiate IL-6 trans-signaling via activation of the ubiquitously expressed membrane-bound ␤-receptor glycoprotein 130 (gp130). Inhibition of IL-6 trans-signaling has been shown to be favorable in numerous inflammatory diseases. Furthermore, different soluble forms of gp130 (sgp130) exist that, together with the sIL-6R, are thought to form a buffer for IL-6 in the blood. However, a functional role for the different sgp130 forms has not been described to date. Here we demonstrate that the metalloproteases ADAM10 and ADAM17 can produce sgp130 by ectodomain shedding of gp130, even though this mechanism only accounts for a minor proportion of sgp130 in the circulation. We further show that full-length sgp130 and the shorter forms sgp130-rheumatoid arthritis-associated peptide (RAPS) and sgp130-E10 are differentially expressed in a cell type-specific manner. Remarkably, full-length sgp130 is expressed by monocytes, but this expression is completely lost during differentiation into macrophages in vitro. Using genetically engineered murine pre-B cells that secrete different forms of sgp130, we found that these secreted sgp130 proteins are able to prevent trans-signaling-driven cell proliferation of the secreting cells, whereas conditioned supernatant from these cells failed to block IL-6 trans-signaling in other cells. Thus, our data suggest that the different sgp130 forms are released from cells into their immediate surroundings and appear to form cell-associated gradients to modulate their own susceptibility for IL-6 trans-signaling.IL-6 is a pleiotropic cytokine with pro-and anti-inflammatory functions (1-4). Classic signaling via the membranebound IL-6R 3 accounts for the regenerative properties of IL-6; trans-signaling via sIL-6R is rather pro-inflammatory (2, 4). In both cases, IL-6 binds initially to the (s)IL-6R, and the IL-6⅐(s)IL-6R complex recruits two signal-transducing gp130 ␤-receptors. This final IL-6⅐(s)IL-6R/gp130 complex formation initiates the activation of intracellular signaling pathways, among them Jak/STAT, PI3K, MAPK, and Src/Yes-associated protein (YAP) (5).Soluble forms of gp130 (sgp130) exist in human serum at concentrations of up to 400 ng/ml (6) and have been shown to act as natural inhibitors of IL-6 trans-signaling (7), although, at high concentrations, they can interfere with classic signaling as well (8). Interestingly, specific inhibition of trans-signaling with an Fc-dimerized version of sgp130 (sgp130Fc) has been shown to be beneficial in numerous inflammatory diseases and cancer (9, 10). sgp130Fc is currently in clinical development as a drug candidate to treat inflammatory bowel diseases (11).gp130 is a transmembrane protein with three N-terminal Iglike domains followed by three fibronectin-type III domains. sgp130 forms with molecular weights of 50, 90, and 110 kDa have been detected in human body fluids (6, 12, 13). Where and how these thre...

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Section: Gp130 Can Be Shed By Adam10 and Adam17 Albeit Withmentioning

confidence: 99%

Different Soluble Forms of the Interleukin-6 Family Signal Transducer gp130 Fine-tune the Blockade of Interleukin-6 Trans-signaling

Wolf

Waetzig

Chalaris

et al. 2016

Journal of Biological Chemistry

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“…Only about 2% of cell surface proteins are released from the surface by ectodomain shedding, indicating that cells selectively shed their protein ectodomains (46). Cleavage often occurs in a juxtamembrane stalk region adjacent to the membrane anchor (47)(48)(49) and may require an unstructured or extended stalk of minimal length (50). In addition to a compactly folded stalk that may protect membrane protein from proteolysis, proteins such as the LDL receptor (51,52), transferrin receptor (53,54), and decay accelerating factor (55) have relatively short juxtamembrane stalk sequences that are O-glycosylated, and when these sites are either mutated or the proteins are expressed in a mutant Chinese hamster ovary (CHO) cell line defective in mucin-type O-glycan synthesis (ldlD), they are proteolytically shed.…”

Section: Discussionmentioning

confidence: 99%

Roles for Trafficking and O-Linked Glycosylation in the Turnover of Model Cell Surface Proteins

Karabasheva

Cole

Donaldson

2014

Journal of Biological Chemistry

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Background: Plasma membrane proteins can be degraded by a number of mechanisms. Results: Turnover rates are determined by endocytosis signals and trafficking to lysosomes, ubiquitination, and ectodomain cleavage. Conclusion: Membrane trafficking to lysosomes and proteolysis at the cell surface determine protein half-life. Significance: Learning how plasma membrane proteins are turned over is critical for understanding protein homeostasis.

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“…This method was also used to clone the cDNA for the chimera hIL-23R-hIL-6R-stalk. The hIL-6R stalk was amplified from a plasmid described previously (11). The expression vector for the synthetic receptor IL-15 ER -IL-23R TIR was generated based on a plasmid described previously (20).…”

Section: Methodsmentioning

confidence: 99%

“…The three FNIII domains of the signal transducing IL-6 ␤ receptor gp130, which are also present in IL-12R␤1, separate the CBMs by about 80 to 100 Å from the plasma membrane (11)(12)(13). If the FNIII domains of IL-12R␤1 have a comparable conformation, the IL-23R stalk regions (human, 140.6 Å; murine, 136.8 Å) are large enough to span this distance in an elongated conformation.…”

mentioning

confidence: 99%

“…Recently, we showed that the stalk region of IL-6R acts as a spacer to position the extracellular domains at a defined distance from the plasma membrane, allowing IL-6 -IL-6R-gp130 complex formation and signal transduction. For biological activity of IL-6R, at least 22 amino acids of the stalk region that span about 83.6 Å (3.8 Å/amino acid) in an elongated, flexible form are needed (11).…”

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confidence: 99%

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Synthetic Deletion of the Interleukin 23 Receptor (IL-23R) Stalk Region Led to Autonomous IL-23R Homodimerization and Activation

Hummel

Ackfeld

Schönberg

et al. 2017

Molecular and Cellular Biology

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Interleukin 23 (IL-23) regulates the development of TH17 cells, which are important for antimicrobial and antifungal responses and autoimmune and chronic inflammatory diseases. IL-23-induced Jak/STAT signaling is mediated via the heterodimeric IL-23 receptor (IL-23R)-IL-12 receptor ␤1 (IL-12R␤1) complex. The typical signal-transducing receptor of the IL-6/IL-12 family contains three extracellularmembrane-proximal fibronectin type III (FNIII) domains, which are not involved in cytokine binding but are mandatory for signal transduction. In place of FNIII-type domains, IL-23R has a structurally undefined stalk. We hypothesized that the IL-23R stalk acts as a spacer to position the cytokine binding domains at a defined distance from the plasma membrane to enable signal transduction. Minor deletions of the murine, but not of the human, IL-23R stalk resulted in unresponsiveness to IL-23. Complete deletion of the human IL-23R stalk and the extended murine IL-23R stalk, including a 20-amino-acid-long duplication of domain 3, however, induced ligandindependent, autonomous receptor activation, as determined by STAT3 phosphorylation and cell proliferation. Ligand-independent, autonomous activity was caused by IL-23R homodimers and was independent of IL-12R␤1. Our data show that deletion of the stalk results in biologically active IL-23R homodimers, thereby creating an asyet-undescribed receptor complex of the IL-6/IL-12 cytokine family.KEYWORDS IL-23 receptor, IL-23 signaling T he proinflammatory cytokine interleukin 23 (IL-23) is a member of the IL-6/IL-12 family (1). IL-23 regulates the development of TH17 cells, which are important mediators of antimicrobial and antifungal responses. Furthermore, they are involved in the pathogenesis of autoimmune and chronic inflammatory diseases (2). IL-23 binding initiates the heterodimerization of the ␤ receptor chains IL-23 receptor (IL-23R) and IL-12R␤1. Subsequently, receptor-associated tyrosine kinase 2 (Tyk2) and Janus kinase 2 (Jak2) activate independent signaling pathways, including the Jak/STAT, the mitogenactivated protein kinase (MAPK)/Erk, and the phosphatidylinositol 3-kinase (PI3K)/Akt pathways. IL-23 predominantly activates STAT3 and to a lesser extent STAT1, STAT4, and STAT5 (3, 4).IL-12R␤1 was considered a ligand binding receptor (5). However, it was demonstrated that IL-12R␤1 is important for kinase binding and activation. Moreover, association of Jak2 with IL-23R is mandatory for IL-23 signaling, whereas Tyk2 seems to be dispensable (6).IL-23R is composed of an N-terminal immunoglobulin-like domain 1 (D1) and a cytokine binding module (CBM) formed by domains 2 and 3 (D2 and D3), which carry

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Minimal Interleukin 6 (IL-6) Receptor Stalk Composition for IL-6 Receptor Shedding and IL-6 Classic Signaling

Cited by 70 publications

References 39 publications

Different Soluble Forms of the Interleukin-6 Family Signal Transducer gp130 Fine-tune the Blockade of Interleukin-6 Trans-signaling

Different Soluble Forms of the Interleukin-6 Family Signal Transducer gp130 Fine-tune the Blockade of Interleukin-6 Trans-signaling

Roles for Trafficking and O-Linked Glycosylation in the Turnover of Model Cell Surface Proteins

Synthetic Deletion of the Interleukin 23 Receptor (IL-23R) Stalk Region Led to Autonomous IL-23R Homodimerization and Activation

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