Txk, a member of the non-receptor tyrosine kinase of the Tec family, forms a complex with poly(ADP-ribose) polymerase 1 and elongation factor 1alpha and regulates interferon-gamma gene transcription in Th1 cells.
We have found previously that Txk, a member of the Tec family tyrosine kinases, is involved importantly in T helper 1 (Th1) cytokine production. However, how Txk regulates interferon (IFN)-gamma gene transcription in human T lymphocytes was not fully elucidated. In this study, we identified poly(ADP-ribose) polymerase 1 (PARP1) and elongation factor 1alpha (EF-1alpha) as Txk-associated molecules that bound to the Txk responsive element of the IFN-gamma gene promoter. Txk phosphorylated EF-1alpha and PARP1 formed a complex with them, and bound to the IFN-gamma gene promoter in vitro. In particular, the N terminal region containing the DNA binding domain of PARP1 was important for the trimolecular complex formation involving Txk, EF-1alpha and PARP1. Several mutant Txk which lacked kinase activity were unable to form the trimolecular complex. A PARP1 inhibitor, PJ34, suppressed IFN-gamma but not interleukin (IL)-4 production by normal peripheral blood lymphocytes (PBL). Multi-colour confocal analysis revealed that Txk and EF-1alpha located in the cytoplasm in the resting condition. Upon activation, a complex involving Txk, EF-1alpha and PARP1 was formed and was located in the nucleus. Collectively, Txk in combination with EF-1alpha and PARP1 bound to the IFN-gamma gene promoter, and exerted transcriptional activity on the IFN-gamma gene.
Maruyama
T
T
Departments of Immunology and Medicine, St Marianna University School of Medicine, Kawasaki, Japan.
Nara
K
K
Yoshikawa
H
H
Suzuki
N
N
D002467:Cell Nucleus / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007371:Interferon-gamma / Q000235:genetics*; D015847:Interleukin-4 / Q000378:metabolism; D019169:Jurkat Cells; D008213:Lymphocyte Activation; D018613:Microscopy, Confocal; D020648:Peptide Elongation Factor 1 / Q000378:metabolism*; D010616:Phenanthrenes / Q000494:pharmacology; D000071137:Poly (ADP-Ribose) Polymerase-1; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D018417:Th1 Cells / Q000378:metabolism*; D014158:Transcription, Genetic
C434926:N-(oxo-5,6-dihydrophenanthridin-2-yl)-N,N-dimethylacetamide hydrochloride; D020648:Peptide Elongation Factor 1; D010616:Phenanthrenes; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D015847:Interleukin-4; D007371:Interferon-gamma; C499320:PARP1 protein, human; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases; C089848:Tec protein-tyrosine kinase; D011505:Protein-Tyrosine Kinases