Signal transducer gp130: biochemical characterization of the three membrane-proximal extracellular domains and evaluation of their oligomerization potential

PFLANZ, Stefan; Kernebeck, Thomas; Giese, Bernd; Herrmann, Andreas; Pachta-Nick, Michael; Stähl, Jutta; Wollmer, Axel; Heinrich, Peter C.; Müller‐Newen, Gerhard; Grötzinger, Joachim

doi:10.1042/bj3560605

Cited by 7 publications

(6 citation statements)

References 7 publications

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“…Previous in vitro biochemical analyses using purified individual D4, D5, and D6 suggested that there could be a low affinity (K D Ͼ 5 M) interaction between D4 domains (33). Our own work shows that even at concentrations of up to 250 M, D4 -D6 is monomeric in solution (supplemental Fig.…”

Section: Discussionmentioning

confidence: 84%

Crystal Structure of the Entire Ectodomain of gp130

Kershaw

Luo

et al. 2010

Journal of Biological Chemistry

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gp130 is the shared signal-transducing receptor subunit for the large and important family of interleukin 6-like cytokines. Previous x-ray structures of ligand-receptor complexes of this family lack the three membrane-proximal domains that are essential for signal transduction. Here we report the crystal structure of the entire extracellular portion of human gp130 (domains 1-6, D1-D6) at 3.6 Å resolution, in an unliganded form, as well as a higher resolution structure of the membraneproximal fibronectin type III domains (D4 -D6) at 1.9 Å . This represents the first atomic resolution structure of the complete ectodomain of any "tall" cytokine receptor. These structures show that other than a reorientation of the D1 domain, there is little structural change in gp130 upon ligand binding. They also reveal that the interface between the D4 and D5 domains forms an acute bend in the gp130 structure. Key residues at this interface are highly conserved across the entire tall receptor family, suggesting that this acute bend may be a common feature of these receptors. Importantly, this geometry positions the C termini of the membrane-proximal fibronectin type III domains of the tall cytokine receptors in close proximity within the transmembrane complex, favorable for receptor-associated Janus kinases to trans-phosphorylate and activate each other.

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Section: Discussionmentioning

confidence: 84%

Crystal Structure of the Entire Ectodomain of gp130

Kershaw

Luo

et al. 2010

Journal of Biological Chemistry

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“…4B). The only monoclonal antibody with sufficient sensitivity for the detection of gp130 in a coprecipitation experiment maps to domain 4 of the extracellular part of the receptor [28]. Therefore, analysis of the ability of the mutants gp130Δ4 and gp130D4 to form complexes with the LIFR by coprecipitation was not possible with the experimental procedure used in this study.…”

Section: Resultsmentioning

confidence: 99%

A functional role of the membrane‐proximal extracellular domains of the signal transducer gp130 in heterodimerization with the leukemia inhibitory factor receptor

Timmermann

Küster

Kurth

et al. 2002

European Journal of Biochemistry

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gp130 is the common signal transducing receptor subunit of interleukin (IL)-6-type cytokines. gp130 either homodimerizes in response to IL-6 and IL-11 or forms heterodimers with the leukemia inhibitory factor (LIF) receptor (LIFR) in response to LIF, oncostatin M (OSM), ciliary neurotrophic factor (CNTF), cardiotrophin-1 (CT-1) or cardiotrophinlike cytokine resulting in the onset of cytoplasmic tyrosine phosphorylation cascades. The extracellular parts of both gp130 and LIFR consist of several Ig-like and fibronectin type III-like domains. The role of the membrane-distal domains of gp130 (D1, D2, D3) and LIFR in ligand binding is well established. In this study we investigated the functional significance of the membrane-proximal domains of gp130 (D4, D5, D6) in respect to heterodimerization with LIFR. Deletion of each of the membrane-proximal domains of gp130 (D4, D5 and D6) leads to LIF unresponsiveness.Replacement of the gp130 domains by the corresponding domains of the related GCSF receptor either restores weak LIF responsiveness (D4-GCSFR), leads to constitutive activation of gp130 (D5-GCSFR) or results in an inactive receptor (D6-GCSFR). Mutation of a specific cysteine in D5 of gp130 (C458A) leads to constitutive heterodimerization with the LIFR and increased sensitivity towards LIF stimulation. Based on these findings, a functional model of the gp130-LIFR heterodimer is proposed that includes contacts between D5 of gp130 and the corresponding domain D7 of the LIFR and highlights the requirement for both receptor dimerization and adequate receptor orientation as a prerequisite for signal transduction.

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“…A well studied example is the gp130 chain in the IL-6 receptor complex. (i) Pflanz et al (34) showed that the bacterially expressed membrane distal gp130 FNIII domain (D4) oligomerizes in solution.…”

Section: Fig 7 Clustering Of Crh2 In Solutionmentioning

confidence: 99%

Leptin Receptor Activation Depends on Critical Cysteine Residues in Its Fibronectin Type III Subdomains

Zabeau

Defeau

Iserentant

et al. 2005

Journal of Biological Chemistry

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The leptin receptor (LR) complex is composed of a single subunit belonging to the class I cytokine receptor family and exists as a preformed complex. The extracellular portion contains two cytokine receptor homology (CRH) domains, separated by an Ig-like domain and followed by two membrane-proximal fibronectin type III (FNIII) domains. The mechanisms underlying ligandinduced receptor activation are still poorly understood. LRs can exist as disulfide-linked dimers at the cell surface, even in the absence of leptin. We evaluated the role of the two unpaired cysteine residues (Cys-672 and Cys-751) in the FNIII domains in receptor clustering, leptin binding, and biological activity. Although mutation of cysteine on position 751 to serine has hardly any effect on ligand binding and receptor activation, the C672S mutant exhibits a marked reduction in STAT3-dependent signaling. The double mutant was completely devoid of biological activity, although leptin binding remained unaffected. Mutation of both residues resulted in complete loss of disulfide bridge formation of FNIII domains in solution. In contrast, no difference was observed in ligand-independent oligomerization of the membranebound receptor, suggesting a role for cysteines in the CRH2 domain in formation of the preformed LR complex. We propose a model wherein leptin-induced clustering of two preformed dimers forms the activated LR complex. Disulfide bridge formation involving Cys-672 and Cys-751 may be necessary for JAK activation and hence signaling.The 16-kDa cytokine-like hormone leptin has been identified as one of the key players in the control of body weight. The product of the ob gene is produced and secreted mainly by adipocytes (1, 2), and plasma protein levels positively correlate with body fat energy stores. Leptin reduces food intake and stimulates energy expenditure by activating its receptor in specific hypothalamic nuclei (3-5). Spontaneous mutations that lead to a functional defect in either leptin (6) or its receptor (7-9) result in a complex syndrome that includes morbid obesity, hypothermia, infertility, hyperglycemia, decreased insulin sensitivity, and hyperlipidemia. Besides serving a weight-regulating function, leptin also plays a role in other processes including metabolism, reproduction, hematopoiesis, and immunity (10 -13).The leptin receptor (LR), 1 the product of the db gene (14), is a member of the class I cytokine receptor family. The extracellular (EC) domain is composed of two so-called cytokine receptor homology (CRH) domains, a membrane distal CRH1 and a membrane proximal CRH2. Both domains are separated by an immunoglobulin-like (Ig) domain and are followed by two fibronectin type III (FNIII) domains proximal to the membrane. The CRH2 domain is necessary and sufficient for leptin binding (15). Despite the lack of any binding affinity for the ligand, the two FNIII and the Ig domains are needed for receptor activation (15, 16). Because of alternative splicing and ectodomain shedding, the LR can exist as six isoforms: a LR long ...

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Signal transducer gp130: biochemical characterization of the three membrane-proximal extracellular domains and evaluation of their oligomerization potential

Cited by 7 publications

References 7 publications

Crystal Structure of the Entire Ectodomain of gp130

Crystal Structure of the Entire Ectodomain of gp130

A functional role of the membrane‐proximal extracellular domains of the signal transducer gp130 in heterodimerization with the leukemia inhibitory factor receptor

Leptin Receptor Activation Depends on Critical Cysteine Residues in Its Fibronectin Type III Subdomains

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