title: The tumor suppressor death-associated protein kinase targets to TCR-stimulated NF-kappa B activation.
abstract: Death-associated protein kinase (DAPK) is a unique multidomain kinase acting both as a tumor suppressor and an apoptosis inducer. The molecular mechanism underlying the effector function of DAPK is not fully understood, while the role of DAPK in T lymphocyte activation is mostly unknown. DAPK was activated after TCR stimulation. Through the expression of a dominant-negative and a constitutively active form of DAPK in T cells, we found that DAPK negatively regulated T cell activation. DAPK markedly affected T cell proliferation and IL-2 production. We identified TCR-induced NF-kappaB activation as a target of DAPK. In contrast, IL-1beta- and TNF-alpha-triggered NF-kappaB activation was not affected by DAPK. We further found that DAPK selectively modulated the TCR-induced translocation of protein kinase Ctheta, Bcl-10, and IkappaB kinase into membrane rafts. Notably, the effect of DAPK on the raft entry was specific for the NF-kappaB pathway, as other raft-associated molecules, such as linker for activation of T cells, were not affected. Our results clearly demonstrate that DAPK is a novel regulator targeted to TCR-activated NF-kappaB and T cell activation.
authors.affiliation: Institute of Immunology, College of Medicine, National Taiwan University, Taipei, Taiwan.
authors.forename: Ya-Ting
authors.initials: YT
authors.lastname: Chuang
authors.forename: Li-Wen
authors.initials: LW
authors.lastname: Fang
authors.forename: Ming-Hsien
authors.initials: MH
authors.lastname: Lin-Feng
authors.forename: Ruey-Hwa
authors.initials: RH
authors.lastname: Chen
authors.forename: Ming-Zong
authors.initials: MZ
authors.lastname: Lai
mesh_terms: D000818:Animals; D051017:Apoptosis Regulatory Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology*; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology*; D002478:Cells, Cultured; D064550:Death-Associated Protein Kinases; D015536:Down-Regulation / Q000235:genetics / Q000276:immunology*; D018390:Gene Targeting; D006801:Humans; D019169:Jurkat Cells; D008213:Lymphocyte Activation / Q000235:genetics / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D010766:Phosphorylation; D034741:RNA, Small Interfering / Q000235:genetics; D011948:Receptors, Antigen, T-Cell / Q000502:physiology*; D015398:Signal Transduction / Q000235:genetics / Q000276:immunology; D013601:T-Lymphocytes / Q000201:enzymology* / Q000276:immunology / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology*
chemical_list: D051017:Apoptosis Regulatory Proteins; D016328:NF-kappa B; D034741:RNA, Small Interfering; D011948:Receptors, Antigen, T-Cell; D025521:Tumor Suppressor Proteins; D064550:Death-Associated Protein Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases