JAK2 is required for induction of the murine DUB-1 gene.
Cytokine receptors activate multiple signal transduction pathways, resulting in the induction of specific target genes. We have recently identified a hematopoietic cell-specific immediate-early gene, DUB-1, that encodes a growth-regulatory deubiquitinating enzyme. The DUB-1 gene contains a 112-bp enhancer element that is specifically induced by the beta c subunit of the interleukin-3 (IL-3) receptor. To investigate the mechanism of DUB-1 induction, we examined the effects of dominant-negative forms of JAK kinases, STAT transcription factors, and Raf-1 in transient transfection assays. In Ba/F3 cells, IL-3 induced a dose-dependent activation of DUB-1-luciferase (luc) and GAS-luc reporter constructs. A dominant-negative form of JAK2 (truncated at amino acid 829) inhibited the induction of DUB-1-luc and GAS-luc by IL-3. A dominant-negative form of STAT5 (truncated at amino acid 650) inhibited the induction of GAS-luc but not DUB-1-luc. A dominant-negative form of Raf-1 inhibited the induction of DUB-1-luc but had no effect on the induction of GAS-luc by IL-3. The requirement for JAK2 in the stimulation of the DUB-1 enhancer was further supported by the suppression of DUB-1 induction in Ba/F3 cells stably expressing the dominant-negative JAK2 polypeptide. We hypothesize that IL-3 activates a JAK2/Raf-1 signaling pathway that is required for DUB-1 induction and is independent of STAT5.
Jaster
R
R
Division of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts 02115, USA.
Zhu
Y
Y
Pless
M
M
Bhattacharya
S
S
Mathey-Prevot
B
B
D'Andrea
A D
AD
D000818:Animals; D002455:Cell Division; D002478:Cells, Cultured; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D010450:Endopeptidases; D004742:Enhancer Elements, Genetic; D015971:Gene Expression Regulation, Enzymologic; D006131:Growth Inhibitors / Q000096:biosynthesis / Q000235:genetics*; D017874:Immediate-Early Proteins / Q000096:biosynthesis / Q000235:genetics*; D016898:Interferon-alpha / Q000378:metabolism; D007377:Interleukin-3 / Q000378:metabolism; D053614:Janus Kinase 2; D051379:Mice; D008894:Milk Proteins; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D019908:Proto-Oncogene Proteins c-raf; D016185:Receptors, Interleukin-3 / Q000378:metabolism; D050799:STAT5 Transcription Factor; D015398:Signal Transduction; D015534:Trans-Activators / Q000378:metabolism; D014162:Transfection
D004268:DNA-Binding Proteins; D006131:Growth Inhibitors; D017874:Immediate-Early Proteins; D016898:Interferon-alpha; D007377:Interleukin-3; D008894:Milk Proteins; D011518:Proto-Oncogene Proteins; D016185:Receptors, Interleukin-3; D050799:STAT5 Transcription Factor; D015534:Trans-Activators; D004247:DNA; D011505:Protein-Tyrosine Kinases; C507926:Jak2 protein, mouse; D053614:Janus Kinase 2; D017346:Protein Serine-Threonine Kinases; D019908:Proto-Oncogene Proteins c-raf; C099271:Dub1 protein, mouse; D010450:Endopeptidases