Figure 15-56. The MAP-kinase serine/threonine phosphorylation pathway activated by Ras.

Figure 15-56The MAP-kinase serine/threonine phosphorylation pathway activated by Ras

Multiple such pathways involving structurally and functionally related proteins operate in all eucaryotes, each coupling an extracellular stimulus to a variety of cell outputs. The pathway activated by Ras begins with a MAP-kinase-kinase-kinase called Raf, which activates the MAP-kinase-kinase Mek, which then activates the MAP-kinase called Erk. Erk in turn phosphorylates a variety of downstream proteins, including other kinases, as well as gene regulatory proteins in the nucleus. The resulting changes in gene expression and protein activity cause complex changes in cell behavior.

From: Signaling through Enzyme-Linked Cell-Surface Receptors

Cover of Molecular Biology of the Cell
Molecular Biology of the Cell. 4th edition.
Alberts B, Johnson A, Lewis J, et al.
New York: Garland Science; 2002.
Copyright © 2002, Bruce Alberts, Alexander Johnson, Julian Lewis, Martin Raff, Keith Roberts, and Peter Walter; Copyright © 1983, 1989, 1994, Bruce Alberts, Dennis Bray, Julian Lewis, Martin Raff, Keith Roberts, and James D. Watson .

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