Upregulation of Jun and Fos family members and permanent JNK activity lead to constitutive AP-1 activation in Theileria-transformed leukocytes.
Theileria parasitises bovine leukocytes and transforms them into proliferating, metastatic tumours, where the infection resembles a leukaemia-like disease. We have studied the signal transduction pathways leading to activation of the transcription factor AP-1 in different transformed leukocytes. Parasite infection leads to an up-regulation of all members of the Jun/Fos family of proteins and surprisingly, this occurs in the absence of any detectable ERK, or p38 MAP kinase activity. In the parasitised B-sarcoma TBL3, AP-1 induction occurs in the absence of any JNK activity. In contrast, in infected macrophage and B-cell lines, AP-1 transcriptional activity is strictly associated with the parasite-induced constitutive activation of JNK and subsequent c-Jun N-terminal phosphorylation. Thus, constant AP-1 transcriptional activity involves both an upregulation in the levels of Jun and Fos proteins and constitutive JNK activation.
Chaussepied
M
M
URA 1960 du CNRS, Département d'Immunologie, Institut Pasteur, Paris, France.
Lallemand
D
D
Moreau
M F
MF
Adamson
R
R
Hall
R
R
Langsley
G
G
D000818:Animals; D001402:B-Lymphocytes / Q000201:enzymology / Q000469:parasitology; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D002417:Cattle; D002478:Cells, Cultured; D004789:Enzyme Activation; D015971:Gene Expression Regulation, Enzymologic; D048031:JNK Mitogen-Activated Protein Kinases; D007962:Leukocytes / Q000201:enzymology / Q000378:metabolism / Q000469:parasitology*; D008213:Lymphocyte Activation; D008264:Macrophages / Q000201:enzymology / Q000469:parasitology; D020928:Mitogen-Activated Protein Kinases; D010766:Phosphorylation; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism*; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism*; D015398:Signal Transduction; D016794:Theileria / Q000235:genetics / Q000502:physiology*; D018808:Transcription Factor AP-1 / Q000378:metabolism*; D015533:Transcriptional Activation; D014407:Tumor Cells, Cultured; D015854:Up-Regulation
D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D018808:Transcription Factor AP-1; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases