Use of a selectable marker regulated by alpha interferon to obtain mutations in the signaling pathway.

Pellegrini, Sandra; John, Joseph F.; Shearer, Moira; Kerr, Ian M.; Stark, George Stark

doi:10.1128/mcb.9.11.4605

Cited by 349 publications

(310 citation statements)

References 55 publications

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“…Thus, IL-8 exerted its inhibitory effects at a later rather than early step in the IFN-mediated pathway. This notion was further supported by the observation that IL-8 had little effect on mRNA expression of the 6-16 gene [15], which can be up-regulated rapidly by IFN treatment [30].…”

Section: Reduction Of Ifn Antiviral Activities By Il-8supporting

confidence: 61%

Potential involvement of IL-8 in the pathogenesis of human cytomegalovirus infection

Murayama

Mukaida

Khabar

et al. 1998

Journal of Leukocyte Biology

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Section: Reduction Of Ifn Antiviral Activities By Il-8supporting

confidence: 61%

Potential involvement of IL-8 in the pathogenesis of human cytomegalovirus infection

Murayama

Mukaida

Khabar

et al. 1998

Journal of Leukocyte Biology

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“…Employing stable cell clones expressing hPNPase old-35 small inhibitory RNA (siRNA) and c-myc, we now provide experimental validation of this hypothesis and establish for the first time the importance of upregulation of in its four variants, U1A (Tyk2-), U3A (STAT1-), U4A (JAK1-) and U5A (IFNAR2-), which have mutations in different molecules involved in the IFN-signaling pathway. 13 As shown in Figure 1C, the upregulation of hPNPase old-35 and downregulation of Myc by IFN-b were observed only in parental 2fTGH cells but not in its mutant clones, which are nonresponsive to type I IFN.…”

Section: Introductionmentioning

confidence: 77%

“…2fTGH cells are wild type in IFN signaling, while its derivates U1A, U3A, U4A and U5A have defects in IFN signaling that could be complemented by expression of TYK2, STAT1, JAK1 or IFNAR2, respectively. 13 Cell growth and viable cell numbers were monitored by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) staining as described. 6 Generation of lentivirus expressing siRNA for hPNPase old-35 Using the software siRNA Target Finder (Ambion, Austin, TX, USA), four potential siRNAs for hPNPase old-35 were designed and the siRNAs were constructed by in vitro transcription using the Silencer siRNA construction kit (Ambion) according to the manufacturer's protocol.…”

Section: Methodsmentioning

confidence: 99%

Defining the mechanism by which IFN-β dowregulates c-myc expression in human melanoma cells: pivotal role for human polynucleotide phosphorylase (hPNPaseold-35)

2006

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Type I interferons (IFN-a/-b) are capable of suppressing c-myc mRNA expression by modulating post-transcriptional processing. However, the molecular mechanism of this phenomenon is poorly understood. We previously established that human polynucleotide phosphorylase (hPNPase old-35 ), a type I IFNinducible 3 0 ,5 0 exoribonuclease involved in mRNA degradation, induces G 1 cell cycle arrest and eventually apoptosis by specifically degrading c-myc mRNA. We now demonstrate a close association between IFN-b-induced hPNPase old-35 upregulation and c-myc downregulation in human melanoma cells. Employing stable melanoma cell clones expressing hPNPase old-35 small inhibitory RNA, we demonstrate that hPNPase old-35 is a key molecule coupled with IFN-b-mediated downregulation of c-myc mRNA. Inhibition of hPNPase old-35 or overexpression of c-myc protects melanoma cells from IFN-bmediated growth inhibition, emphasizing the importance of hPNPase old-35 upregulation and consequent c-myc downregulation in IFN-b-induced growth inhibition and apoptosis induction. In these contexts, targeted overexpression of hPNPase old-35 might be a novel therapeutic strategy for c-myc-overexpressing and IFN-resistant tumors, such as melanomas.

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“…Cell Culture-Parental 2C4 cells and mutant U4A, ␥2A, and U1D cells were derived as described previously (40,41,49). Cells were grown in Dulbecco's modified Eagle's medium supplemented with 10% (v/v) heat-inactivated fetal calf serum.…”

Section: Methodsmentioning

confidence: 99%

Janus Kinase-dependent Activation of Insulin Receptor Substrate 1 in Response to Interleukin-4, Oncostatin M, and the Interferons

Burfoot

Rogers

Watling

et al. 1997

Journal of Biological Chemistry

115

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In addition to a role in response to insulin and insulinlike growth factors, insulin receptor substrate 1 (IRS-1) is phosphorylated in response to IL-4, the interferons (IFNs) and oncostatin M (OSM). Here mutant cell lines lacking JAK1, JAK2, or Tyk2 were used to determine the role(s) of the Janus kinase (JAK) family of protein-tyrosine kinases in IRS-1 phophorylation. 32D cells, which do not express IRS proteins, were analyzed for any requirement for these proteins in response to the IFNs. For the mutant human fibrosarcoma cell lines, phosphorylation of IRS-1 through the insulin-like growth factor receptor is independent of JAK1, JAK2, or Tyk2. In contrast, phosphorylation of IRS-1 mediated by the Type I IFNs, IL-4, and OSM is JAK-dependent. For the ␣␤-IFNs, activation of IRS-1 is dependent on JAK1 and Tyk2, consistent with the interdependence of these kinases in the IFN-␣␤ response. Neither IRS-1 nor IRS-2 was detectably activated by IFN-␥. Consistent with this, activation of neither IRS proteins appears to be an absolute requirement for an antiproliferative or an antiviral response to the IFNs. For IL-4 and OSM phosphorylation of IRS-1 in the human fibrosarcoma cells is largely dependent on JAK1 but can also be mediated through Tyk2 or JAK2. Activation of phosphatidylinositol 3 -kinase in response to IL-4 and OSM, at least, was also JAK-dependent. The JAKs are, therefore, required not only for STAT activation but also for the activation, through a variety of different types of cytokine receptor, of an additional signaling pathway(s) through IRS-1 and phosphatidylinositol 3 -kinase.Receptors that have an intrinsic tyrosine kinase domain recruit and activate a variety of signal transducers. Insulin receptor substrate 1 (IRS-1) 1 is a cytosolic protein of ϳ180 kDa in mass that is tyrosyl-phosphorylated at multiple sites through activated insulin and insulin-like growth factor 1 (IGF-1) receptors (1, 2). An L(X) 4 NPXY(p)XSXP motif has been identified in the insulin receptor as being important for the recruitment of the IRS proteins. IRS-1 contains multiple YMXM and YXXM tyrosine motifs, which when phosphorylated can recruit Src homology 2 domain-containing proteins, including the p85␣ regulatory subunit of PI 3Ј-kinase, SHP-2, Grb-2, Crk, and Nck (3, 4). Phosphorylated IRS-1, therefore, can mediate a variety of responses including a mitogenic response and activation of PI 3Ј-kinase.Common themes involving the role of tyrosine kinases and proteins with Src homology 2 domains have emerged to describe broadly the mechanism of signal transduction by many growth factors and cytokines. Signal transduction pathways utilizing the JAK (Janus kinase) family of protein-tyrosine kinases and the STATs (signal transducers and activators of transcription) are activated in response to polypeptide ligands including many cytokines, some growth factors and the interferons (IFNs). STAT activation mediated through the JAKs occurs in receptor complexes at the cell membrane. There are four known mammalian JAKs: JAK1, JAK2, JAK3, and T...

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Use of a selectable marker regulated by alpha interferon to obtain mutations in the signaling pathway.

Abstract: We have selected mutations in genes encoding components of the signaling pathway for alpha interferon (IFN-a)

Cited by 349 publications

References 55 publications

Potential involvement of IL-8 in the pathogenesis of human cytomegalovirus infection

Potential involvement of IL-8 in the pathogenesis of human cytomegalovirus infection

Defining the mechanism by which IFN-β dowregulates c-myc expression in human melanoma cells: pivotal role for human polynucleotide phosphorylase (hPNPaseold-35)

Janus Kinase-dependent Activation of Insulin Receptor Substrate 1 in Response to Interleukin-4, Oncostatin M, and the Interferons

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