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Query: EC:2.7.10.2 (
focal adhesion kinase
)
44,029
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Reconstitution with mouse interleukin-2 (IL-2) receptor subunits demonstrated that the mouse IL-2 receptor complex was different from the human complex in the alpha chain requirement for the functional mouse receptor complex. The heterotrimeric complex of the mouse exogenous alpha and beta chains and the endogenous
gamma chain
on mouse lymphoid BW5147 cells showed the ability to bind IL-2 with high affinity, resulting in IL-2-induced tyrosine phosphorylation of a cytosolic tyrosine kinase,
JAK3
, which is involved in IL-2-dependent signals. Exogenous introduction of the beta chain with the endogenous
gamma chain
, however, could neither confer appreciable IL-2 binding nor IL-2-induced signal transduction on BW5147 cells, unlike the human beta gamma heterodimer. Mouse spleen CD8+ cells, not having the alpha chain initially, showed IL-2-dependent cell proliferation only when expression of the alpha chain was induced. Collectively, these results illustrate that the functional mouse IL-2 receptor complex necessarily includes the alpha chain, and that the regulation of CD8+ T cell growth during immune reaction depends upon alpha chain expression.
...
PMID:Differences in the interleukin-2 (IL-2) receptor system in human and mouse: alpha chain is required for formation of the functional mouse IL-2 receptor. 748 34
In human B cells, interleukin 4 (IL4) acts in regulating proliferation, antigen expression, isotype switching and differentiation. These different effects are mediated through the IL4R complex including the IL2R
gamma chain
(gamma c) and a specific p130/140 binding unit referred below as human Interleukin 4 Receptor (IL4-R). Here, we studied the signal transduction events following IL4R activation and leading to CD23 expression on resting B cells. We demonstrate that IL4R triggering induced the tyrosine phosphorylation of
JAK3
and of a p170 protein. Coimmunoprecipitation of
JAK3
with the IL4R suggests a physical association which exists prior to IL4R complex stimulation. Orthovanadate treatment, while having no effect on IL4-induced p130 phosphorylation, leads to the hyperphosphorylation of the p170 and inhibits IL4-induced CD23 expression. These suggest that two mandatory steps exist in early IL4 signaling: one controlled by
JAK3
activation and the other by the p170 phosphoprotein.
...
PMID:JAK3 associates with the human interleukin 4 receptor and is tyrosine phosphorylated following receptor triggering. 753 55
The functional interleukin 2 (IL-2) receptors contain the beta and gamma chains which are necessary for the transduction of cell growth signals. Monoclonal antibodies specific for the beta chain and
gamma chain
coimmunoprecipitated
JAK1
and 114-kDa
JAK2
tyrosine kinases, respectively. Tyrosine phosphorylation of
JAK1
and
JAK2
was induced upon IL-2 stimulation, and IL-2 activated the
JAK2
kinase. These results demonstrate that the
JAK1
and
JAK2
tyrosine kinases are physically associated with the beta chain and
gamma chain
, respectively, and suggest that regulation of the kinases may be linked to IL-2-induced signal transduction.
...
PMID:Physical association of JAK1 and JAK2 tyrosine kinases with the interleukin 2 receptor beta and gamma chains. 804 79
We have investigated the role of
JAK3
in interleukin 2 (IL-2)-induced signal transduction with a human T cell line, ED40515(-), lacking expression of the IL-2 receptor
gamma chain
and its sublines transfected with wild-type or mutant cDNAs of the IL-2 receptor
gamma chain
. Our results demonstrated that the membrane-proximal cytoplasmic region, encompassing the src homology region 2 (SH2)-like subdomain, of the
gamma chain
is essential for association and activation of
JAK3
. Furthermore, IL-2-induced activation of
JAK3
paralleled induction of the c-myc gene and DNA synthesis but not induction of the c-fos and c-jun genes. These results support the hypothesis that
JAK3
plays a pivotal role in the IL-2 receptor-mediated signals for cell growth.
...
PMID:Interleukin 2-induced activation of JAK3: possible involvement in signal transduction for c-myc induction and cell proliferation. 808 65
We have previously reported on the expression of interleukin-4 receptors (IL-4R) on many human epithelial cancer cells; however, the binding characteristics, structure, function, and signal transduction through the IL-4R in cancer cells is not known. IL-4 binding characteristics were determined in human colon carcinoma cell lines by a 125I-IL-4 binding assay, which demonstrated that the HT-29 and WiDr colon cancer cell lines expressed high affinity IL-4R (Kd = 200 pM). Cross-linking experiments revealed a major band of 140 kDa and a broad band at 70 kDa. While the common
gamma chain
of IL-2R is associated with IL-4R in immune cells and is similar in size to the 70-kDa protein, this chain was not expressed in these colon cancer cells. Interestingly, IL-13, which has many functions similar to IL-4, inhibited 125I-IL-4 binding to both the 140- and 70-kDa molecules. Next, we investigated the mechanism of IL-4-induced signal transduction in colon cancer cells. After stimulation with IL-4, a 170-kDa band was primarily phosphorylated within 1 min of exposure and was identified as insulin receptor substrate-1. In addition, by immunoprecipitation assay, three other phosphorylated bands were identified as
JAK1
,
JAK2
, and Tyk2 tyrosine kinases. The phosphorylation of
JAK1
and
JAK2
was induced by IL-4 stimulation; however, Tyk2 was constitutively phosphorylated, and IL-4 treatment further augmented this phosphorylation. The kinetics and in vitro kinase assays demonstrated that
JAK1
,
JAK2
, and Tyk2 were phosphorylated within minutes and that
JAK1
and
JAK2
were activated after IL-4 exposure. Contrary to observations in immune cells.
JAK3
mRNA was neither detected in colon cancer cells nor did IL-4 treatment cause phosphorylation of
JAK3
. These data indicate that in colon carcinoma cells
JAK1
,
JAK2
, Tyk2, and insulin receptor substrate-1 are phosphorylated after IL-4 stimulation. In addition, as is the case in lymphoid cells, IL-4 activated and phosphorylated signal transducers and activators of transcription (IL-4-STAT or STAT-6) protein in both colon cancer cell lines. These results indicate that the IL-4R complex is composed of different subunits in different tissues and shares a component with the IL-13R complex. In addition, we demonstrate for the first time that like its family members (e.g. IL-3 and GM-CSF), IL-4 can phosphorylate and activate JAK-2 kinase.
...
PMID:Receptors for interleukin (IL)-4 do not associate with the common gamma chain, and IL-4 induces the phosphorylation of JAK2 tyrosine kinase in human colon carcinoma cells. 853 May 27
X-linked severe combined immunodeficiency (XSCID) is a lethal disease caused by a defect in the gene encoding the common
gamma chain
(gamma-c) of the receptor for interleukin-2 (IL-2), IL-4, IL-7, IL-9, and IL-15. Allogeneic bone marrow transplantation, the current therapy of choice for this defect, is often complicated by graft-versus-host disease and/or incomplete reconstitution of B-lymphocyte functions. Correction of the gene defect at the level of the autologous lymphohematopoietic progenitors could therefore represent an improvement in the medical management of these patients. To study the feasibility of a gene therapy approach for XSCID, a retroviral vector expressing gamma-c was used to transduce Epstein-Barr virus-transformed B-cell lines derived from patients with XSCID. After transduction, XSCID cells newly expressed gamma-c on the cell surface at levels comparable to those observed on B-cell lines obtained from normal donors. Moreover, the reconstituted gamma-c restored function to the IL-2 and IL-4 receptors as shown by signal transduction mediated by phosphorylation of the
JAK1
and
JAK3
members of the Janus family of tyrosine kinases and by restoration of cellular proliferation in response to IL-2.
...
PMID:Retroviral-mediated gene correction for X-linked severe combined immunodeficiency. 860 22
Mutations affecting the expression of the Janus family kinase
JAK3
were recently shown to be responsible for autosomal recessive severe combined immunodeficiency (SCID).
JAK3
-deficient patients present with a clinical phenotype virtually indistinguishable from boys affected by X-linked SCID, a disease caused by genetic defects of the common
gamma chain
(gamma c) that is a shared component of the receptors for IL-2, IL-4, IL-7, IL-9, and IL-15. The specific interaction of
JAK3
and gamma c represents the biochemical basis for the similarities between these two immunodeficiencies. Both forms of SCID are characterized by recurrent, severe infections leading to death in infancy unless successfully treated by allogeneic bone marrow transplantation. Because of the potentially lethal complications associated with allogeneic bone marrow transplantation and the frequent lack of suitable marrow donors, the development of alternative forms of therapy is highly desirable. To this end, we investigated a retroviral-mediated gene correction approach for
JAK3
-deficiency. A vector carrying a copy of
JAK3
cDNA was constructed and used to transduce B cell lines derived from patients with
JAK3
-deficient SCID. We demonstrate restoration of
JAK3
expression and phosphorylation upon IL-2 and IL-4 stimulation. Furthermore, patients' cells transduced with
JAK3
acquired the ability to proliferate normally in response to IL-2. These data indicate that the biological defects of
JAK3
-deficient cells can be efficiently corrected in vitro by retroviral-mediated gene transfer, thus providing the basis for future investigation of gene therapy as treatment for
JAK3
-deficient SCID.
...
PMID:In vitro correction of JAK3-deficient severe combined immunodeficiency by retroviral-mediated gene transduction. 867 91
Interleukin-9 (IL-9), a T-cell-derived cytokine, interacts with a specific receptor associated with the IL-2 receptor
gamma chain
. In this report, we analyze the functional domains of the human IL-9 receptor transfected into mouse lymphoid cell lines. Three different functions were examined: growth stimulation in factor-dependent pro-B Ba/F3 cells, protection against dexamethasone-induced apoptosis, and Ly-6A2 induction in BW5147 lymphoma cells. The results indicated that a single tyrosine, at position 116 in the cytoplasmic domain, was required for all three activities. In addition, we observed that human IL-9 reduced the proliferation rate of transfected BW5147 cells, an effect also dependent on the same tyrosine. This amino acid was necessary for IL-9-mediated tyrosine phosphorylation of the receptor and for STAT activation but not for IRS-2/4PS activation or for
JAK1
phosphorylation, which depended on a domain closer to the plasma membrane. We also showed that
JAK1
was constitutively associated with the IL-9 receptor. Activated STAT complexes induced by IL-9 were found to contain STAT1, STAT3, and STAT5 transcription factors. Moreover, sequence homologies between human IL-9 receptor tyrosine 116 and tyrosines (of other receptors activating STAT3 and STAT5 were observed. Taken together, these data indicate that a single tyrosine of the IL-9 receptor, required for activation of three different STAT proteins, is necessary for distinct activities of this cytokine, including proliferative responses.
...
PMID:A single tyrosine of the interleukin-9 (IL-9) receptor is required for STAT activation, antiapoptotic activity, and growth regulation by IL-9. 875 28
Cytokines that bind to the interleukin-2 (IL-2) receptor common
gamma chain
(gamma c), including IL-2, IL-4, IL-7, IL-9, and IL-15, are important for the growth and differentiation of T and B lymphocytes, natural killer cells, macrophages, and monocytes. These cytokines have overlapping biological effects that in part result from the use of the shared receptor subunit gamma c. Recently it has become clear that these cytokines activate a number of important intracellular signaling molecules, including the Janus kinases
JAK1
and
JAK3
and members of the transcription factor family of signal transducers and activators of transcription (STATs). The discovery of these signaling pathways has led to important new insights into their role in lymphocyte maturation, as it has emerged that mutations in the genes encoding both gamma c and
JAK3
result in similar forms of severe combined immunodeficiency (SCID). In this review we examine the structure and function of cytokine receptors and the signaling pathways involved in their regulation of gene expression. Furthermore, we discuss recent advances that have led to a better understanding of how cytokines elicit intracellular responses, as well as their role in normal lymphoid development.
...
PMID:Signaling by IL-2 and related cytokines: JAKs, STATs, and relationship to immunodeficiency. 886 27
Both IL-2 and IL-4 bind to receptors containing the common
gamma chain
and
JAK3
. Although
JAK3
is required for proper lymphoid development, the precise roles of this kinase in IL-2 and IL-4 signaling in lymphocytes have not been defined. Here, we have studied IL-2 and IL-4 signaling in B cell lines lacking
JAK3
. Although IL-2-induced phosphorylation of IL-2R beta,
JAK1
, and STAT5 all required the presence of
JAK3
, IL-4-mediated phosphorylation of
JAK1
, STAT6, and insulin receptor substrates 1 and 2 did not. However, IL-4-induced effects were clearly improved following
JAK3
expression. These data indicate that IL-4 signaling occurs in the absence of of
JAK3
, but is comparatively inefficient. These findings may help in understanding the pathogenesis of the immunodeficiency that occurs with mutations of
JAK3
and may suggest a mechanism for the pleiotropic effects of IL-4.
...
PMID:Signaling via IL-2 and IL-4 in JAK3-deficient severe combined immunodeficiency lymphocytes: JAK3-dependent and independent pathways. 898 19
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