Cells respond to changes in their environment, or to mitogenic events at the cell surface by generating signals. Intracellular signals induced as a result, pass from the cell surface to the nucleus via a multitude of mediators, and terminate in cellular proliferation, differentiation or even cell death. Protein phosphorylation is an integral part of signal transduction, and protein kinases are important second messengers in signal transduction pathways. Binding of SV40 to its receptor on CV-1 cells induced signals that led to the upregulation of the primary response genes, c-myc and c-jun. The major histocompatibility complex class I proteins are an essential component of the SV40 receptor. Antibodies against the MHC class I proteins also led to the upregulation of c-myc and c-jun. The serine/threonine kinase Raf and the mitogen activated protein kinases (or MAPK), are highly conserved and play an integral role in signal transduction. Along with the GTP-binding protein p21Ras, the activation of Raf and MAPK form a central paradigm of cell signaling in eukaryotic cell. Activation of protein kinase C, another serine/threonine kinase has also been implied in certain systems. A study of the signaling pathways been elicited by extracellular SV40 imply protein kinase C to be involved in the upregulation of c-myc and c-jun, but provide no evidence for the involvement of either Raf, or MAPK. Antibodies against the MHC class I proteins, on the other hand, indicate the activation of protein kinase C, Raf and MAPK. Moreover, experimental data suggests the anti-class I-induced activation of protein kinase C to be dependent on tyrosine kinases that lie upstream of protein kinase C. Analysis of the signaling pathways being evoked by SV40 and antibodies against class I proteins suggests the existence of separate and distinct signaling pathways being induced by SV4O, and anti-MHC class I antibodies in CV-1 cells.
| Identifer | oai:union.ndltd.org:UMASS/oai:scholarworks.umass.edu:dissertations-7628 |
| Date | 01 January 1996 |
| Creators | Dangoria, Nandita Sinha |
| Publisher | ScholarWorks@UMass Amherst |
| Source Sets | University of Massachusetts, Amherst |
| Language | English |
| Detected Language | English |
| Type | text |
| Source | Doctoral Dissertations Available from Proquest |
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