UNIPROT:P04141 - FACTA Search

Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Target Concepts:

Query: UNIPROT:P04141 (granulocyte-macrophage colony-stimulating factor)
6,790 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The human interleukin-3 receptor (IL-3R) is a heterodimer that comprises an IL-3 specific alpha chain (IL-3R alpha) and a common beta chain (beta C) that is shared with the receptors for granulocyte-macrophage colony-stimulating factor (GM-CSF) and IL-5. These receptors belong to the cytokine receptor superfamily, but they are structurally and functionally more related to each other and thus make up a distinct subfamily. Although activation of the normal receptor occurs only in the presence of ligand, the underlying mechanisms are not known. We show here that human IL-3 induces heterodimerization of IL-3R alpha and beta c and that disulfide linkage of these chains is involved in receptor activation but not high-affinity binding. Monoclonal antibodies (MAb) to IL-3R alpha and beta c were developed which immunoprecipitated, in the absence of IL-3, the respective chains from cells labelled with 125I on the cell surface. However, in the presence of IL-3, each MAb immunoprecipitated both IL-3R alpha and beta c. IL-3-induced receptor dimers were disulfide and nondisulfide linked and were dependent on IL-3 interacting with both IL-3R alpha and beta c. In the presence of IL-3 and under nonreducing conditions, MAb to either IL-3R alpha or beta c immunoprecipitated complexes with apparent molecular weights of 215,000 and 245,000 and IL-3R alpha and beta c monomers. Preincubation with iodoacetamide prevented the formation of the two high-molecular-weight complexes without affecting noncovalent dimer formation or high-affinity IL-3 binding. Two-dimensional gel electrophoresis and Western blotting (immunoblotting) demonstrated the presence of both IL-3R alpha and beta c in the disulfide-linked complexes. IL-3 could also be coimmunoprecipitated with anti-IL-3R alpha or anti-beta c MAB, but it was not covalently attached to the receptor. Following IL-3 stimulation, only the disulfide-linked heterodimers exhibited reactivity with antiphosphotyrosine antibodies, with beta c but not IL-3R alpha being the phosphorylated species. A model of IL-3R activation is proposed which may be also applicable to the related GM-CSF and IL-5 receptors.
...
PMID:Human interleukin-3 (IL-3) induces disulfide-linked IL-3 receptor alpha- and beta-chain heterodimerization, which is required for receptor activation but not high-affinity binding. 864 15

The hematopoietic cytokine granulocyte-macrophage colony-stimulating factor (GM-CSF) mediates its activity through binding to cell surface receptors. The receptor for GM-CSF belongs to a superfamily of cytokine receptors characterized by a conserved extracellular motif. The high affinity GM-CSF receptor (GMR) consists of two transmembrane anchored subunits; a ligand binding alpha subunit (transmembrane GMRalpha) and a signal transducing beta subunit (GMRbeta), both of which belong to the cytokine receptor superfamily. The human GM-CSF receptor alpha subunit also exists in a soluble form (solGMRalpha), which antagonizes GM-CSF activity in vitro. We directly tested the potential for solGMRalpha to interact with GMRbeta in vitro. Our experiments demonstrated that exogenous solGMRalpha, even in the presence of GM-CSF, does not interact with GMRbeta on the cell surface. However, when solGMRalpha and GMRbeta are co-expressed in baby hamster kidney cells, solGMRalpha is retained on the cell surface and forms a functional intermediate affinity GM-CSF binding complex (Kd = 331 pM). In addition, the cell surface expression of solGMRalpha is independent of the presence of GM-CSF as demonstrated using flow cytometry. Cells expressing only solGMRalpha do not show cell surface retention or form functional GM-CSF cell surface binding complexes. Sequencing of our GMRbeta clone revealed a nucleotide substitution (A --> C) resulting in the substitution of Ala for Glu at position 9 from the amino terminus of the mature GMRbeta peptide. Because the GMRbeta (A --> C) clone is capable of forming functional high affinity receptors with transmembrane GMRalpha (Kd = 64 pM), we feel that the cell surface retention of solGMRalpha is independent of the GMRbeta mutation. We suggest that the co-expression and interaction of solGMRalpha and GMRbeta represents a previously unrecognized GM-CSF receptor complex and a novel, ligand-independent mechanism of cytokine receptor assembly.
...
PMID:Ligand-independent cell surface expression of the human soluble granulocyte-macrophage colony-stimulating factor receptor alpha subunit depends on co-expression of the membrane-associated receptor beta subunit. 866 62

It is well established that granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin (IL)-1 and tumour necrosis factor-alpha (TNF-alpha) are involved in Langerhans' cell (LC) development and dendritic cell traffic. However, little is known about the pattern of cytokine receptors on human LC and their modulation during different stages of maturation. The expression of cytokine receptors was studied by flow cytometry on both freshly isolated LC (fLC) and 72-hr cultured LC (cLC). Epidermal cell suspensions enriched in LC were obtained after skin trypsinization and Ficoll-Hypaque gradient. LC were identified by their CD1a positivity. Although the majority of fLC were positive for the alpha chain of GM-CSF receptor (GM-CSFR), the beta chain of GM-CSFR was detected only on 15% of CD1a+ cells. fLC were also positive for IL-1 receptor (IL-1R) type 1, IL-1R type 2, 75,000 molecular weight TNF receptor (TNFR) and interferon-gamma receptor (IFN-gamma R). IL-6R and its transducing signal gp130 were present in a subset of fLC. Granulocyte colony-stimulating factor receptor (G-CSFR), macrophage colony-stimulating factor receptor (M-CSFR), the alpha and beta chain of IL-2R, IL-4R, IL-7R, IL-8R and 55,000 molecular weight TNFR were not detected on fLC. After culture, LC up-regulated the expression of both the alpha and beta chains of GM-CSFR, IL-1R type 2, alpha and beta chains of IL-2R, IL-6R and gp130. In contrast, IL-1R type 1 and 75,000 molecular weight TNFR were down-modulated and the expression of IFN-gamma R was not affected by culture. These results suggest that LC undergo changes in the cytokine receptor repertory during in vitro maturation.
...
PMID:Flow cytometric analysis of cytokine receptors on human Langerhans' cells. Changes observed after short-term culture. 869 97

Cytokines regulate cell growth and differentiation by inducing the expression of specific target genes. We have recently isolated a cytokine-inducible, immediate-early cDNA, DUB-1, that encodes a deubiquitinating enzyme. The DUB-1 mRNA was specifically induced by the receptors for interleukin-3, granulocyte-macrophage colony-stimulating factor, and interleukin-5, suggesting a role for the beta common (betac subunit known to be shared by these receptors. In order to identify the mechanism of cytokine induction, we isolated a murine genomic clone for DUB-1 containing a functional promoter region. The DUB-1 gene contains two exons, and the nucleotide sequence of its coding region is identical to the sequence of DUB-1 cDNA. Various regions of the 5' flanking region of the DUB-1 gene were assayed for cytokine-inducible activity. An enhancer region that retains the beta c-specific inducible activity of the DUB-1 gene was identified. Enhancer activity was localized to a 112-bp fragment located 1.4 kb upstream from the ATG start codon. Gel mobility shift assays revealed two specific protein complexes that bound to this minimal enhancer region. One complex was induced by betac signaling, while the other was noninducible. Finally, the membrane-proximal region of human betac was required for DUB-1 induction. In conclusion, DUB-1 is the first example of an immediate-early gene that is induced by a specific subunit of a cytokine receptor. Further analysis of the DUB-1 enhancer element may reveal specific determinants of a betac-specific signaling pathway.
...
PMID:The murine DUB-1 gene is specifically induced by the betac subunit of interleukin-3 receptor. 875 39

The fps/fes proto-oncogene encodes a cytoplasmic protein tyrosine kinase that is thought to participate in signaling pathways involving members of the cytokine receptor superfamily, including those for erythropoietin, granulocyte-macrophage colony-stimulating factor, leukemia inhibitory factor, oncostatin M, ciliary neurotropic factor, and interleukins 3, 4, 6, and 11. Expression of fps/fes has been detected in hematopoietic cells, vascular endothelial cells, and cell types arising from all three germ layers during early development. Here, we describe fps/fes expression in developing and adult tissues from normal mice or from transgenic animals overexpressing wild-type or activated mutant fps/fes alleles. The highest levels of fps/fes expression were seen in angioblasts of early yolk sac blood islands, chondrocytes, vascular endothelial cells, neuronal cells, and several epithelial cell types, including those of the choroid plexus and the uterus. Fps/Fes protein was concentrated in the perinuclear region of cultured neuronal, myeloid, epithelial, and vascular endothelial cells, and a chimeric Fps/Fes-green fluorescence protein colocalized with gamma-adaptin, a marker for the trans-Golgi apparatus. These observations suggest the involvement of Fps/Fes in vesicle transport processes in cells with prominent secretory functions.
...
PMID:The fps/fes tyrosine kinase is expressed in myeloid, vascular endothelial, epithelial, and neuronal cells and is localized in the trans-golgi network. 880 11

The receptors for human interleukin-3 (IL-3) and human granulocyte-macrophage colony-stimulating factor (GM-CSF), hIL-3R, hGM-CSFR, respectively, consists of two subunits, alpha and beta, both of which are members of the cytokine receptor superfamily. Phosphorylation of tyrosine residues in the hGMR beta subunit and several cellular proteins is observed after hGM-CSF stimulation. We analyzed the role of tyrosine residues in the hGMR beta subunit and the nature of tyrosine kinase, JAK2, in hGMR signal transduction using several hGMR beta subunit mutants. In addition to the box1 region, a membrane distal region (a.a. 544-589) of the hGMR beta was required for c-fos activation. Only one tyrosine residue (Tyr577) existed within the region 544 to 589, and substitution of Tyr577 to phenylalanine in GMR beta 589 resulted in loss of c-fos activation. In contrast, the same substitution in a wild type receptor did not affect GM-CSF induced activities such as c-fos messenger RNA (mRNA) induction and proliferation, but the substitution abolished Shc phosphorylation. These results suggest that the activation of Shc is not essential for c-fos activation and several tyrosine residues cooperate for c-fos activation. It is well documented that IL-3 or GM-CSF activate JAK2 in BA/F3 cells. The role of JAK2 in IL-3/GM-CSF functions, however, is largely unknown. We examined the role of JAK2 in GM-CSF induced signaling pathways. Dominant negative JAK2 (delta JAK2) lacking the C-terminus kinase domain suppressed IL-3/GM-CSF induced c-fos activation and c-myc activation and proliferation, suggesting that JAK2 was involved in both signaling pathways. Protein tyrosine phosphatase SHP-2 (also called PTP 1D) and Shc were phosphorylated by IL-3/GM-CSF in BA/F3 cells; however, these phosphorylation events were inhibited by the expression of delta JAK2. Taken together, these results indicate the JAK2 is a primary kinase regulating all the known activities of GM-CSF. JAK2 mediates GM-CSF induced c-fos activation through receptor phosphorylation and Shc/PTP 1D activation.
...
PMID:Roles of JAK kinases in human GM-CSF receptor signal transduction. 897 26

The interleukin-3 (IL-3), granulocyte-macrophage colony-stimulating factor, and IL-5 receptor alpha chains are each composed of three extracellular domains, a transmembrane domain and a short intracellular region. Domains 2 and 3 constitute the cytokine receptor module (CRM), typical of the cytokine receptor superfamily; however, the function of the N-terminal domain is not known. We have investigated the functions of the N-terminal and C-terminal domains of the IL-3 receptor (IL-3R) alpha chain. We find that cells transfected with the receptor beta chain (h beta c) and a truncated IL-3R alpha that is devoid of the intracellular region fail to proliferate or to activate STAT5 in response to human IL-3, despite binding the IL-3 with affinity indistinguishable from that of full-length receptor. In addition, IL-3-induced phosphorylation of h beta c was not detected. Thus, the IL-3R alpha intracellular region does not contribute detectably to stabilization of the receptor/ligand complex, but is essential for signal propagation. In contrast, a truncated IL-3R alpha with the N-terminal domain deleted interacts functionally with the beta chain; mouse cells transfected with these receptor chains proliferate in response to human IL-3 and STAT5 transcription factor is activated. High- and low-affinity binding sites are retained, although the affinity for IL-3 is decreased 15-fold, indicating a significant role for the N-terminal domain in IL-3 binding.
...
PMID:Roles of the N and C terminal domains of the interleukin-3 receptor alpha chain in receptor function. 902 15

Thymocytes show differential cytokine responses, depending on the stage of differentiation. Whether these responses are due to preferential cytokine receptor expression or due to downstream signaling mechanisms is unknown. In this study, we examined the relationship between receptor expression and T-cell proliferation or differentiation using thymocytes from transgenic mice constitutively expressing the human granulocyte-macrophage colony-stimulating factor (hGM-CSF) receptor. Transgenic CD4- CD8-, CD4+ CD8-, and CD4- CD8+ cells proliferated when cultured with hGM-CSF in vitro, whereas CD4+ CD8+ cells failed to proliferate. To examine the effect of hGM-CSF receptor signaling on T-cell development, we used fetal thymic organ cultures. The addition of exogenous hGM-CSF resulted in the failure of CD4- CD8- cells to differentiate into CD4+ CD8+ cells. To more closely identify this maturational inhibition, we reconstituted normal fetal lobes with sorted pro-T-, pre-T-, or post-pre-T-precursor cells from transgenic mice. The addition of hGM-CSF to these cultures led to a block in both pro-T- and pre-T-cell differentiation, whereas the more mature post-pre-T cells differentiated normally. We propose that hGM-CSF receptor signaling during T-cell development results in a stage-specific inhibition of thymic precursor maturation.
...
PMID:Human granulocyte-macrophage colony-stimulating factor (hGM-CSF) induces inhibition of intrathymic T-cell development in hGM-CSF receptor transgenic mice. 902 58

Semi-quantitative, polymerase chain reaction (PCR) is used to uncover the patterns of cytokine transcription in the mouse thymus from day 14 to day 20 of gestation, a time period which includes many of the important events in thymic ontogeny. Interleukin 4 (IL-4), IL-7 and interferon gamma (IFN-gamma) mRNA is abundant from fetal day (Fd) 14-16, corresponding with the period of rapid proliferation of immature thymocytes in vivo. As the level of mRNA for these cytokines diminishes, the induction and increased expression of IL-3 and IL-2 occurs. The transcription of these cytokines correlates temporally with the period of proliferation-dependent phenotypic differentiation between Fd 16 and 20. The thymic epithelium (TE)-derived cytokines including IL-1alpha, IL-6 and granulocyte-macrophage colony-stimulating factor (GM-CSF) begin to be transcribed between Fd 14-15 and show peak mRNA abundance from Fd 16-20. IL-5, tumour necrosis factor alpha (TNF-alpha) and LT (lymphotoxin or TNF-beta) constitute a fourth group of cytokines, along with the IL-4 receptor (IL-4R), which are transcribed at an even level throughout the fetal period. The IL-2 receptor beta chain (IL-2Rbeta) and IL-10 show abundant mRNA from Fd 14-20 and have a peak level of mRNA content on Fd 16. Taken together, these studies uncover complex, overlapping patterns of cytokine gene expression. The mRNA abundance and pattern of expression of each cytokine or cytokine receptor may indicate the relative contribution that it makes to different stages of fetal thymic ontogeny.
...
PMID:Semi-quantitative polymerase chain reaction analysis of cytokine and cytokine receptor gene expression during thymic ontogeny. 934 2

The granulocyte-macrophage colony-stimulating factor (GM-CSF) receptor is expressed on normal and malignant hematopoietic cells as well as on cells from other organs in which it transduces a variety of functions. Despite the widespread expression and pleiotropic nature of the GM-CSF receptor, little is known about its assembly and activation mechanism. Using a combination of biochemical and functional approaches, we have found that the human GM-CSF receptor exists as an inducible complex, analogous to the interleukin-3 (IL-3) receptor, and also as a preformed complex, unlike the IL-3 receptor or indeed other members of the cytokine receptor superfamily. We found that monoclonal antibodies to the GM-CSF receptor alpha chain (GMR alpha) and to the common beta chain of the GM-CSF, IL-3, and IL-5 receptors (beta(c)) immunoprecipitated both GMR alpha and beta(c) from the surface of primary myeloid cells, myeloid cell lines, and transfected cells in the absence of GM-CSF. Further association of the two chains could be induced by the addition of GM-CSF. The preformed complex required only the extracellular regions of GMR alpha and beta(c), as shown by the ability of soluble beta(c) to associate with membrane-anchored GMR alpha or soluble GMR alpha. Kinetic experiments on eosinophils and monocytes with radiolabeled GM-CSF, IL-3, and IL-5 showed association characteristics unique to GM-CSF. Significantly, receptor phosphorylation experiments showed that not only GM-CSF but also IL-3 and IL-5 stimulated the phosphorylation of GMR alpha-associated beta(c). These results indicate a pattern of assembly of the heterodimeric GM-CSF receptor that is unique among receptors of the cytokine receptor superfamily. These results also suggest that the preformed GM-CSF receptor complex mediates the instantaneous binding of GM-CSF and is a target of phosphorylation by IL-3 and IL-5, raising the possibility that some of the biologic activities of IL-3 and IL-5 are mediated through the GM-CSF receptor complex.
...
PMID:The human granulocyte-macrophage colony-stimulating factor (GM-CSF) receptor exists as a preformed receptor complex that can be activated by GM-CSF, interleukin-3, or interleukin-5. 937 81

<< Previous 1 2 3 4 5 6 Next >>