![]() ![]() Cleveland JL, Jansen HW, Bister K, Fredrickson TN, Morse HC, 3rd, Ihle JN, Rapp UR. ![]() Tyrosine kinase oncogenes abrogate interleukin-3 dependence of murine myeloid cells through signaling pathways involving c-myc: conditional regulation of c-myc transcription by temperature-sensitive v-abl. Cleveland JL, Dean M, Rosenberg N, Wang JY, Rapp UR.The suppression of drug-induced apoptosis by activation of v-ABL protein tyrosine kinase. Protein kinase C-mediated serine phosphorylation directly activates Raf-1 in murine hematopoietic cells. Ras-dependent and -independent pathways target the mitogen-activated protein kinase network in macrophages. Büscher D, Hipskind RA, Krautwald S, Reimann T, Baccarini M.cAMP antagonizes p21ras-directed activation of extracellular signal-regulated kinase 2 and phosphorylation of mSos nucleotide exchange factor. Burgering BM, Pronk GJ, van Weeren PC, Chardin P, Bos JL.Myristylation is required for Tyr-527 dephosphorylation and activation of pp60c-src in mitosis. Activation of c-myc expression by c-Abl is independent of both the DNA binding function of c-Abl and the c-myc EP site. Inhibition of growth and modulation of gene expression in human lung carcinoma in athymic mice by site-selective 8-Cl-cyclic adenosine monophosphate. Ally S, Clair T, Katsaros D, Tortora G, Yokozaki H, Finch RA, Avery TL, Cho-Chung YS.This may not be the complete list of references from this article. The Full Text of this article is available as a PDF (1.4M). In conclusion, these results suggest (i) that Raf-1 participates in v-abl transformation via an Erk-independent pathway by providing a survival signal which complements c-myc in transformation, and (ii) that cAMP agonists might become useful for the treatment of malignancies where abl oncogenes are involved, such as chronic myeloid leukemias. Using estrogen-regulated c-myc and temperature-sensitive Raf-1 mutants, we found that Raf-1 activation could protect cells from c-myc-induced apoptosis. Myc activation has been previously shown to be essential for transformation by oncogenic Abl proteins. v-abl-transformed cells featured high constitutive levels of expression of c-myc, which were not reduced following PKA activation. The diverse biological responses correlated with the status of c-myc gene expression. In contrast to PKA activators, a Mek inhibitor did not induce apoptosis. Overexpression of Raf-1 in v-abl-transformed cells partially protected the cells from apoptosis induced by PKA activation. ![]() PKA activation induced apoptosis in v-abl-transformed cells while reverting v-raf transformation without severe cytopathic effects. Raf inhibition substantially diminished the activities of Erks in v-raf-transformed cells but not in v-abl-transformed cells, indicating that v-abl can activate Erks by a Raf-1-independent pathway. In both cell types the activities of Raf-1 and v-raf were almost completely suppressed after activation of the cyclic AMP-dependent kinase (protein kinase A ), whereas the v-abl kinase was not affected. The activities of the Erks were constitutively elevated in both v-raf- and v-abl-transformed cells. In v-abl-transformed cells the endogenous Raf-1 protein was phosphorylated on tyrosine and displayed high constitutive kinase activity. Raf-1 can activate a transforming signalling cascade comprising the consecutive activation of Mek and extracellular-signal-regulated kinases (Erks). Here we investigate the role of the Raf-1 kinase in transformation by the v-abl oncogene. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |