Structural and functional studies on the human hepatic interleukin-6 receptor. Molecular cloning and overexpression in HepG2 cells.
Ontology highlight
ABSTRACT:
SUBMITTER: Schooltink H
PROVIDER: S-EPMC1151293 | biostudies-other | 1991 Aug
REPOSITORIES: biostudies-other
Similar Datasets
Project description:Interleukin-1 alpha (IL-1alpha) regulates a wide range of important cellular processes. In this study for the first time, we report the cloning, expression, biophysical, and biological characterization of the human interleukin-1alpha. Human IL-1alpha has been expressed in Escherichia coli in high yields ( approximately 4mg per liter of the bacterial culture). The protein was purified to homogeneity ( approximately 98% purity) using affinity chromatography and size exclusion chromatography. Results of the steady-state fluorescence and 2D NMR experiments show that the recombinant IL-1alpha is in a folded conformation. Far-UV circular dichroism (CD) data suggest that IL-1alpha is an all beta-sheet protein with a beta-barrel architecture. Isothermal titration calorimetry (ITC) experiments show that the recombinant IL-1alpha binds strongly (K(d) approximately 5.6 x 10(-7) M) to S100A13, a calcium binding protein that chaperones the in vivo release of IL-1alpha into the extracellular compartment. Recombinant IL-1alpha was observed to exhibit strong cytostatic effect on human umbilical vascular endothelial cells. The findings of the present study not only pave way for an in-depth structural investigation of the molecular mechanism(s) underlying the non-classical release of IL-1alpha but also provide avenues for the rational design of potent inhibitors against IL-1alpha mediated pathogenesis.
| S-EPMC3605035 | biostudies-literature
Project description:Signal transduction by the IL-36 receptor (IL-36R) is linked to several human diseases. However, the structure and function of the IL-36R is not well understood. A molecular model of the IL-36R complex was generated and a cell-based reporter assay was established to assess the signal transduction of recombinant subunits of the IL-36R. Mutational analyses and functional assays have identified residues of the receptor subunit IL-1Rrp2 needed for cytokine recognition, stable protein expression, disulfide bond formation and glycosylation that are critical for signal transduction. We also observed that, overexpression of ectodomain (ECD) of Il-1Rrp2 or IL-1RAcP exhibited dominant-negative effect on IL-36R signaling. The presence of IL-36 cytokine significantly increased the interaction of IL-1Rrp2 ECD with the co-receptor IL-1RAcP. Finally, we found that single nucleotide polymorphism A471T in the Toll-interleukin 1 receptor domain (TIR) of the IL-1Rrp2 that is present in ?2% of the human population, down-regulated IL-36R signaling by a decrease of interaction with IL-1RAcP.
| S-EPMC4974375 | biostudies-literature
Project description:Progestagenic sex steroid hormones play critical roles in reproduction across vertebrates, including teleost fish. To further our understanding of how progesterone modulates testis functions in fish, we set out to clone a progesterone receptor (pgr) cDNA exhibiting nuclear hormone receptor features from zebrafish testis. The open reading frame of pgr consists of 1854 bp, coding for a 617-amino acid-long protein showing the highest similarity with other piscine Pgr proteins. Functional characterization of the receptor expressed in mammalian cells revealed that zebrafish Pgr exhibited progesterone-specific, dose-dependent induction of reporter gene expression, with 17 alpha,20 beta-dihydroxy-4-pregnen-3-one (DHP), a typical piscine progesterone, showing the highest potency. Expression of pgr mRNA: 1) appeared in embryos at 8 h after fertilization; 2) was significantly higher in developing ovary than in early transforming testis at 4 wk of age but vice versa in young adults at 12 wk of age, and thus resembling the expression pattern of the germ cell marker piwil1; and, 3) was restricted to Leydig and Sertoli cells in adult testis. Zebrafish testicular explants released DHP concentration dependently in response to high concentrations of recombinant zebrafish gonadotropins. In addition, DHP stimulated 11-ketotestosterone release from zebrafish testicular explants, but only in the presence of its immediate precursor, 11 beta-hydroxytestosterone. This stimulatory activity was blocked by a Pgr antagonist (RU486), suggesting that 11 beta-hydroxysteroid dehydrogenase activity was stimulated by DHP via Pgr. Our data suggest that DHP contributes to the regulation of Leydig cell steroidogenesis, and potentially--via Sertoli cells--also to germ cell differentiation in zebrafish testis.
| S-EPMC2802120 | biostudies-literature
Project description:Toll-like receptors (TLRs) are a large family of germ-line encoded pattern recognition receptors (PRRs) that recognize pathogen-associated molecular patterns and evoke the relevant innate immune responses. TLR8 is a member of several endosome nucleic acid-sensing TLRs; however little attention has been paid to murine TLR8 (mTLR8) compared with other endosome nucleic acid-sensing TLRs. In the present study, mTLR8 was cloned using reverse transcription-polymerase chain reaction from murine peripheral blood mononuclear cells and its function in regulating innate immune response was characterized. The open reading frame of mTLR8 consists of 3,099 bps and encodes 1,032 amino acids. It contains typical leucine-rich repeats, a transmembrane domain and a Toll/interleukin-1 receptor domain, and it shares a high level of identity with other mammalian species. The expression of mTLR8 has been widely observed in different tissues, and higher expression levels of mTLR8 have mainly been detected in the heart, spleen and lung. Overexpression of mTLR8 is required for the activation of transcription factor nuclear factor-κB and the production of tumor necrosis factor-α. However, mTLR8 is not able to activate interferon regulatory factor 3 or activator protein 1, nor can it induce interferon-α in HEK293T cells. These results indicate that mTLR8, as an important PRR, is indeed functional and is vital role in the activation of innate immune responses. This study may aid in determining the molecular basis of the interactions between mTLR8 and pathogens.
| S-EPMC4732850 | biostudies-literature
Project description:BACKGROUND:The mitogen-activated protein kinases (MAPKs), as a part of the MAPKKK-MAPKK-MAPK cascade, play crucial roles in plant development as an intracellular signal transduction pathway to respond various environmental signals. However, few MAPKK have been functionally characterized in grapevine. RESULTS:In the study, five MAPKK (MKK) members were identified in grapevine (cultivar 'Pinot Noir'), cloned and designated as VvMKK1-VvMKK5. A phylogenetic analysis grouped them into four sub-families based on the similarity of their conserved motifs and gene structure to Arabidopsis MAPKK members. qRT-PCR results indicated that the expression of VvMKK1, VvMKK2, VvMKK4, and VvMKK5 were up-regulated in mature leaf and young blades, and roots, but exhibited low expression in leaf petioles. VvMKK2, VvMKK3, and VvMKK5 genes were differentially up-regulated when grapevine leaves were inoculated with spores of Erisyphe necator, or treated with salicylic acid (SA), ethylene (ETH), H2O2, or exposed to drought, indicating that these genes may be involved in a variety of signaling pathways. Over expression of VvMKK2 and VvMKK4 genes in transgenic Arabidopsis plants resulted in the production of seeds with a significantly higher germination and survival rate, and better seedling growth under stress conditions than wild-type plants. Overexpression of VvMKK2 in Arabidopsis improved salt and drought stress tolerance while overexpression of VvMKK4 only improved salt stress tolerance. CONCLUSIONS:Results of the present investigation provide a better understanding of the interaction and function of MAPKKK-MAPKK-MAPK genes at the transcriptional level in grapevine and led to the identification of candidate genes for drought and salt stress in grapes.
| S-EPMC7203792 | biostudies-literature
Project description:The cellular receptor for murine thymic stromal lymphopoietin (TSLP) was detected in a variety of murine, but not human myelomonocytic cell lines by radioligand binding. cDNA clones encoding the receptor were isolated from a murine T helper cell cDNA library. TSLP receptor (TSLPR) is a member of the hematopoietin receptor family. Transfection of TSLPR cDNA resulted in only low affinity binding. Cotransfection of the interleukin 7 (IL-7)Ralpha chain cDNA resulted in conversion to high affinity binding. TSLP did not activate cells from IL-7Ralpha(-/)- mice, but did activate cells from gammac(-/)- mice. Thus, the functional TSLPR requires the IL-7Ralpha chain, but not the gammac chain for signaling.
| S-EPMC2193276 | biostudies-literature
Project description:A cDNA encoding the Clostridium perfringens enterotoxin receptor gene (CPE-R) was cloned from an expression library of enterotoxin-sensitive Vero cells. The nucleotide sequence of CPE-R showed that the enterotoxin receptor consists of 209 amino acids with a calculated molecular mass of 22,029 D. This receptor is highly hydrophobic, contains four putative transmembrane segments, and has significant similarity to the rat androgen withdrawal apoptosis protein RVP1 and the mouse oligodendrocyte specific protein, the functions of which are unknown. The expression of CPE-R was detected in the enterotoxin-sensitive Vero, Hep3B, and Intestine 407 cell lines, but not in the enterotoxin-insensitive K562 and JY cell lines. The CPE-R gene product expressed in enterotoxin-resistant L929 cells bound to enterotoxin specifically and directly and with high affinity and rendered the cells sensitive to the toxin, indicating that the cloned receptor is functional. Results showed that enterotoxin could not assemble into a complex with a defined structure unless it interacted with the receptor. From these results, it is proposed that the enterotoxin receptor is required for both target cell recognition and pore formation in the cell membrane.
| S-EPMC2132509 | biostudies-literature
Project description:The murine interleukin 4 receptor (IL-4R) exists as a transmembrane protein transducing pleiotropic IL-4 functions, or as soluble (s)IL-4-binding molecule with potent immunoregulatory effects. In this study we identified and characterized a murine IL-4R allotype. Sequence analysis of the IL-4R cDNA of BALB/c mice revealed 18 base substitutions leading to three extracellular and five cytoplasmic amino acid changes when compared with the published IL-4R sequence of C57BL/6 mice. Analyses with allotype-specific mAbs revealed that AKR/J and SJL/J mice possess the newly identified BALB/c IL-4R allotype whereas the IL-4Rs of C3H, CBA, DBA-2, and FVB/N mice are identical to that of the C57BL/6 mouse. The extracellular Thr49 to Ile substitution abrogates one N-glycosylation site in the naturally occurring BALB/c IL-4R as well as in the experimentally point mutated C57BL/6-T49I sIL-4R, and both molecules display a nearly threefold reduction in IL-4-neutralizing activity compared to the C57BL/6 sIL-4R. In line with this, a significantly enhanced dissociation rate of IL-4 was detected for the BALB/c IL-4R allotype by surface plasmon resonance and in radioligand binding studies with IL-4R-transfected cell lines. These findings suggest that the altered ligand binding behavior of the newly described IL-4R allotype may influence the IL-4 responsiveness, thus contributing to the diverse phenotypes of inbred mouse strains in IL-4-dependent diseases.
| S-EPMC2199121 | biostudies-literature
Project description:Human interleukin 5 (IL-5) plays an important role in proliferation and differentiation of human eosinophils. We report the isolation of cDNA clones from cDNA libraries of human eosinophils by using murine IL-5 receptor alpha chain cDNA as a probe. Analysis of the predicted amino acid sequence indicated that the human IL-5 receptor has approximately 70% amino acid sequence homology with the murine IL-5 receptor and retains features common to the cytokine receptor superfamily. One cDNA clone encodes a glycoprotein of 420 amino acids (Mr 47,670) with an NH2-terminal hydrophobic region (20 amino acids), a glycosylated extracellular domain (324 amino acids), a transmembrane domain (21 amino acids), and a cytoplasmic domain (55 amino acids). Another cDNA encodes only the extracellular domain of this receptor molecule. Other cDNA clones encode molecules having diversified cytoplasmic domains. COS7 cells transfected with the cDNA expressed a approximately 60-kD protein and bound IL-5 with a single class of affinity (Kd = 250-590 pM). The Kd values were similar to that observed in normal human eosinophils. In contrast to the murine 60-kD alpha chain, which binds IL-5 with low affinity (Kd = approximately 10 nM), the human alpha chain homologue can bind IL-5 with much higher affinity by itself. RNA blot analysis of human cells demonstrated two transcripts (approximately 5.3 and 1.4 kb). Both of them were expressed in normal human eosinophils and in erythroleukemic cell line TF-1, which responds to IL-5. The human IL-5 receptor characterized in this paper is essential for signal transduction, because expression of this molecule in murine IL-3-dependent cell line FDC-P1 allowed these cells to proliferate in response to IL-5.
| S-EPMC2119102 | biostudies-other
Project description:Interleukin-15 (IL-15) and IL-2 possess distinct immunological functions despite both signaling through IL-2Rβ and the common cytokine receptor γ-chain, γc, We find that in the IL-15/IL-15Rα/IL-2Rβ/γc quaternary complex structure, IL-15 heterodimerizes IL-2Rβ and γc identically to the IL-2/IL-2Rα/IL-2Rβ/γc complex, despite differing receptor-binding chemistries. IL-15Rα dramatically increases the affinity of IL-15 for IL-2Rβ, and this allostery is required for IL-15 trans-signaling versus IL-2 cis-signaling. Consistent with the identical IL-2Rβ/γc dimer geometry, IL-2 and IL-15 exhibited similar signaling properties in lymphocytes, with any differences resulting from disparate receptor affinities. Thus, IL-15 and IL-2 induce similar signals, and the cytokine-specificity of IL-2Rα versus IL-15Rα determines cellular responsiveness. These results provide important new insights for specific development of IL-15- versus IL-2-based immunotherapeutics. RNA-Seq is conducted in mouse CD8+ T cells, not treated or treated with IL2 or IL15 for indicated concentrations (1nM or 500nM) and times (4hr or 24hr).
2012-11-01 | E-GEOD-40350 | biostudies-arrayexpress