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

---

Query: EC:2.7.10.2 (focal adhesion kinase)
44,029 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The common cytokine receptor gamma chain (gamma c), an essential component of the receptors for IL-2, IL-4, IL-7, IL-9, and IL-15, is critical for the development and function of lymphocytes. Recently, a novel lymphokine (IL-21) and its receptor (IL-21R alpha) were described which profoundly affect the growth and activation state of B, T, and NK cells in concert with other lymphokines or stimuli [Parrish-Novak, J., et al. (2000) Nature 408, 57-63]. In this report, we show that gamma c is also a required signaling component of the IL-21 receptor (IL-21R) using the gamma c-deficient X-linked severe combined immunodeficiency (XSCID) lymphoblastoid cell line JT, and JT cells reconstituted with gamma c (JT/gamma c). Moreover, we demonstrate a functional requirement for both gamma c and the gamma c-associated Janus family tyrosine kinase 3 (JAK3) in IL-21-induced proliferation of pro-B-lymphoid cells engineered to express human IL-21R alpha (BaF3/IL-21R alpha). Retroviral-mediated transduction of wild-type gamma c into XSCID JT cells restored function to the IL-21R, as shown by IL-21-induced tyrosine phosphorylation of JAK1 and JAK3, and downstream activation of STAT5, in JT/gamma c cells as well as BaF3/IL-21R alpha and primary splenic B cells. In contrast, IL-21 failed to activate the JAK-STAT pathway in nonreconstituted JT cells. Monoclonal antibodies specific for the gamma c chain effectively inhibited IL-21-induced growth of BaF3/IL-21R alpha cells, supporting a functional role for this molecule in the IL-21R complex. In addition, the specific JAK3 tyrosine kinase inhibitor WHI-P131 significantly reduced IL-21-induced proliferation of BaF3/IL-21R alpha cells. Taken together, these results definitively demonstrate that IL-21-mediated signaling requires the gamma c chain, and indicate that JAK3 is an essential transducer of gamma c-dependent survival and/or mitogenic signals induced by this cytokine.
...
PMID:The common gamma chain (gamma c) is a required signaling component of the IL-21 receptor and supports IL-21-induced cell proliferation via JAK3. 1209 91

Mucus hypersecretion and persistent airway inflammation are common features of various airway diseases, such as asthma, chronic obstructive pulmonary disease, and cystic fibrosis. One key question is: does the associated airway inflammation in these diseases affect mucus production? If so, what is the underlying mechanism? It appears that increased mucus secretion results from increased mucin gene expression and is also frequently accompanied by an increased number of mucous cells (goblet cell hyperplasia/metaplasia) in the airway epithelium. Many studies on mucin gene expression have been directed toward Th2 cytokines such as interleukin (IL)-4, IL-9, and IL-13 because of their known pathophysiological role in allergic airway diseases such as asthma. However, the effect of these cytokines has not been definitely linked to their direct interaction with airway epithelial cells. In our study, we treated highly differentiated cultures of primary human tracheobronchial epithelial (TBE) cells with a panel of cytokines (interleukin-1alpha, 1beta, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 15, 16, 17, 18, and tumor necrosis factor alpha). We found that IL-6 and IL-17 could stimulate the mucin genes, MUC5B and MUC5AC. The Th2 cytokines IL-4, IL-9, and IL-13 did not stimulate MUC5AC or MUC5B in our experiments. A similar stimulation of MUC5B/Muc5b expression by IL-6 and IL-17 was demonstrated in primary monkey and mouse TBE cells. Further investigation of MUC5B expression demonstrated that IL-17's effect is at least partly mediated through IL-6 by a JAK2-dependent autocrine/paracrine loop. Finally, evidence is presented to show that both IL-6 and IL-17 mediate MUC5B expression through the ERK signaling pathway.
...
PMID:Stimulation of airway mucin gene expression by interleukin (IL)-17 through IL-6 paracrine/autocrine loop. 1262 14

Janus kinase 3 (Jak3) is a nonreceptor tyrosine kinase essential for signaling via cytokine receptors that comprise the common gamma-chain (gammac), i.e., the receptors for IL-2, IL-4, IL-7, IL-9, IL-15, and IL-21. Jak3 is preferentially expressed in hemopoietic cells and is up-regulated upon cell differentiation and activation. Despite the importance of Jak3 in lymphoid development and immune function, the mechanisms that govern its expression have not been defined. To gain insight into this issue, we set out to characterize the Jak3 promoter. The 5'-untranslated region of the Jak3 gene is interrupted by a 3515-bp intron. Upstream of this intron and the transcription initiation site, we identified an approximately 1-kb segment that exhibited lymphoid-specific promoter activity and was responsive to TCR signals. Truncation of this fragment revealed that core promoter activity resided in a 267-bp fragment that contains putative Sp-1, AP-1, Ets, Stat, and other binding sites. Mutation of the AP-1 sites significantly diminished, whereas mutation of the Ets sites abolished, the inducibility of the promoter construct. Chromatin immunoprecipitation assays showed that histone acetylation correlates with mRNA expression and that Ets-1/2 binds this region. Thus, transcription factors that bind these sites, especially Ets family members, are likely to be important regulators of Jak3 expression.
...
PMID:Characterization and analysis of the proximal Janus kinase 3 promoter. 1279 34

IL-21 is a recently described type I cytokine produced by activated CD4(+) T cells that profoundly affects the growth, survival, and functional activation of B, T, and natural killer lymphocytes in concert with other cytokines or activating stimuli. Structurally, IL-21 is predicted to display a 4-helix-bundle-type fold with significant homology to IL-2, IL-4, and IL-15 and mediates its biologic effects through a novel type I cytokine receptor, IL-21R, in conjunction with the common cytokine receptor gamma chain (gammac) of the IL-2, IL-4, IL-7, IL-9, and IL-15 receptors. As a new member of the gammac-dependent cytokine family, there is significant interest in IL-21, in part because of its potential to provide new insights into the immunologic phenotype caused by gammac deficiency. IL-21R knockout mice have been generated that have normal lymphoid cell development yet exhibit impaired production of the immunoglobulin IgG(1) and increased IgE responses after immunization. As expected for cytokines that use gammac, recent studies indicate that IL-21 induces Janus kinase 1 (JAK1) and JAK3 activation to initiate signal transduction, but unlike these other gammac-dependent cytokines, which predominantly activate signal transducer and activator of transcription 5 (STAT5), IL-21 preferentially activates STAT1 and STAT3. IL-21 potently enhances primary antigen responses and the effector functions of T and natural killer cells and stimulates IFN-gamma production alone or in concert with other cytokines. Thus, on the basis of primary structure, receptor composition, and biologic activities, IL-21 is a new IL-2-family cytokine that participates in both innate and adaptive immunity and might be important for the development of a T(H)1 immune response.
...
PMID:IL-21: a novel IL-2-family lymphokine that modulates B, T, and natural killer cell responses. 1465 53

Mice expressing the X-linked immunodeficiency (xid) mutation lack functional Bruton's tyrosine kinase and were shown to be specifically deficient in peritoneal B-1 lymphocytes. We have previously shown that IL-9, a cytokine produced by TH2 lymphocytes, promotes B-1 cell expansion in vivo. To determine whether IL-9 overexpression might compensate the xid mutation for B-1 lymphocyte development, we crossed xid mice with IL-9-transgenic mice. In this model, IL-9 restored normal numbers of mature peritoneal B-1 cells that all belonged to the CD5(-) B-1b subset. Despite this normal B-1 lymphocyte number, IL-9 failed to restore classical functions of B-1 cells, namely, the production of natural IgM Abs, the T15 Id Ab response to phosphorylcholine immunization, and the antipolysaccharide humoral response against Streptococcus pneumoniae. By using bromelain-treated RBC, we showed that the antigenic repertoire of these IL-9-induced B-1b lymphocytes was different from the repertoire of classical CD5(+) B-1a cells, indicating that the lack of B-1 function by B-1b cells is associated with distinct Ag specificities. Taken together, our data show that B-1b cell development can restore the peritoneal B-1 population in xid mice but that these B-1b cells are functionally distinct from CD5(+) B-1a lymphocytes.
...
PMID:IL-9-induced expansion of B-1b cells restores numbers but not function of B-1 lymphocytes in xid mice. 1512 95

Janus tyrosine kinases (JAKs) are cytoplasmic protein tyrosine kinases that play a crucial role in the initial steps of cytokine signaling. JAK3, a member of JAK kinase family of four (JAK1, JAK2, JAK3 and TYK2), is abundantly expressed in lymphoid cells. JAK3 has been found to initiate signaling of interleukin (IL)-2, IL-4, IL-7, IL-9, IL-13 and IL-15. Indispensable role of JAK3 in lymphocyte development and function has been revealed recently. Because of the involvement of JAK3 in T cell activation and proliferation, and the documented genetic evidence for the role of JAK3 in autoimmune or transplant -induced inflammatory disorders, the selective targeting of JAK3 in T cells may potentially be clinically beneficial in T cell-derived pathologic disorders. In this review we discuss inhibitors of JAK3 as a new class of immunomodulatory agents with immunosuppressive, anti-inflammatory, anti-allergic, and anti-leukemic properties. Preclinical data from multiple experimental model systems of autoimmune diabetes, allergy, solid organ transplantation, pancreatic islet transplantation and bone marrow transplantation are discussed in the context of the clinical need for new immunomodulatory agents with such properties.
...
PMID:Targeting Janus kinase 3 in the treatment of leukemia and inflammatory diseases. 1517 21

IL-9 is a multifunctional cytokine secreted by TH2 lymphocytes. Besides its role during immune responses, its growth factor and antiapoptotic activities on multiple transformed cells suggest a potential role in tumorigenesis. Indeed, IL-9 overexpression induces thymic lymphomas in mice, and IL-9 production is associated with Hodgkin disease and HTLV-I transformed T cells in humans. IL-9 activities are mediated by a specific receptor chain that forms a heterodimeric receptor with the common gamma chain also involved in IL-2,4,7,15 and 21 signaling. The IL-9 receptor and common gamma chains associate with JAK1 and JAK3, respectively and trigger the STAT-1, -3 and -5, IRS and RAS-MAPK pathways. Moreover, in vitro, dysregulated IL-9 response can lead to autonomous cell growth and malignant transformation of lymphoid cells associated with constitutive activation of the Jak/STAT pathway.
...
PMID:IL-9 and its receptor: from signal transduction to tumorigenesis. 1562 23

Cytokines are critical in regulating the development and function of diverse cells. Janus kinase 3 (Jak3) is a tyrosine kinase expressed in hematopoietic cells that associates with the common gamma chain (gammac) and is required for signaling for a family of cytokines including interleukin-2 (IL-2), IL-4, IL-7, IL-9, IL-15, and IL-21; deficiency of either Jak3 or gammac results in severe combined immunodeficiency (SCID). While Jak3 is essential for lymphoid-cell development, the potential roles for Jak3 in regulating dendritic cells (DCs) were unclear. Herein, we show that although CD8+CD11c+ splenic DCs are absent in Jak3-/- mice, bone marrow-derived DCs developed normally in vitro from Jak3-/- precursor cells. In fact, the survival of Jak3-/- DCs was enhanced, and they expressed lower levels of proapoptotic proteins. Jak3-/- DCs exhibited normal antigen uptake and up-regulation of costimulatory molecules. However, Jak3-/- DCs produced more IL-12 and IL-10 in response to Toll-like receptor ligands, which correlated with enhanced T helper 1 (Th1) differentiation in vivo. In summary, Jak3 is not essential for DC development but unexpectedly appears to be an important negative regulator. These results may be relevant clinically for patients with SCID who have undergone hematopoietic stem cell transplantation and for patients who might be treated with a Jak3 inhibitor.
...
PMID:Jak3 negatively regulates dendritic-cell cytokine production and survival. 1602 May 5

Constitutive activation of the JAK-STAT pathway is frequent in cancer and contributes to oncogenesis. Here, we took advantage of the Ba/F3 cell line, a murine proB cell line dependent on IL-3 for growth, to analyse mechanisms of constitutive STAT activation in vitro. Cytokine-independent and tumorigenic Ba/F3 cell lines were derived from a two-step selection process. Cells transfected with a defective IL-9 receptor acquire IL-9 responsiveness during a first step of selection, and progress after a second selection step to autonomously growing tumorigenic cells. Microarray analysis pointed to JAK1 overexpression as a key genetic event in this transformation. Overexpression of JAK1 not only increased the sensitivity to IL-9 but also allowed a second selection step toward cytokine-independent growth with constitutive STAT activation. This progression was dependent on a functional FERM and kinase JAK1 domain. Similar results were observed after JAK2, JAK3 and TYK2 overexpression. All autonomous cell lines showed an activation of STAT5, ERK1-2 and AKT but only TYK2-overexpressing cell lines showed a constitutive activation of STAT3. Thus, JAK overexpression can be considered as one of the oncogenic events leading to the constitutive activation of the JAK-STAT pathway.
...
PMID:JAK kinases overexpression promotes in vitro cell transformation. 1787 4

Aberrant signal transduction contributes substantially to leukemogenesis. The Janus kinase 1 (JAK1) gene encodes a cytoplasmic tyrosine kinase that noncovalently associates with a variety of cytokine receptors and plays a nonredundant role in lymphoid cell precursor proliferation, survival, and differentiation. We report that somatic mutations in JAK1 occur in individuals with acute lymphoblastic leukemia (ALL). JAK1 mutations were more prevalent among adult subjects with the T cell precursor ALL, where they accounted for 18% of cases, and were associated with advanced age at diagnosis, poor response to therapy, and overall prognosis. All mutations were missense, and some were predicted to destabilize interdomain interactions controlling the activity of the kinase. Three mutations that were studied promoted JAK1 gain of function and conferred interleukin (IL)-3-independent growth in Ba/F3 cells and/or IL-9-independent resistance to dexamethasone-induced apoptosis in T cell lymphoma BW5147 cells. Such effects were associated with variably enhanced activation of multiple downstream signaling pathways. Leukemic cells with mutated JAK1 alleles shared a gene expression signature characterized by transcriptional up-regulation of genes positively controlled by JAK signaling. Our findings implicate dysregulated JAK1 function in ALL, particularly of T cell origin, and point to this kinase as a target for the development of novel antileukemic drugs.
...
PMID:Somatically acquired JAK1 mutations in adult acute lymphoblastic leukemia. 1836 73


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

---