Skip to main content
. Author manuscript; available in PMC: 2011 Mar 23.
Published in final edited form as: Annu Rev Neurosci. 2010;33:221–243. doi: 10.1146/annurev-neuro-060909-153215

Figure 2.

Figure 2

Neurofibromin and cell signaling. Neurofibromin (NF1) is a GTPase activating protein (GAP) that functions as a negative regulator of Ras-MAPK signaling cascade. Guanine-nucleotide exchange factors (GEFs), such as SOS, may counteract the GAP function of NF1. On the other hand, NF1 acts as an activator of adenylate cyclase (AC). Note that the key pathways are grossly simplified in this diagram. For example, phosphatidylinositol 3-kinase (PI3K)-AKT-mTOR cascade is also modulated by NF1, but is omitted in the diagram. Arrows and barred lines indicate activation and suppression, respectively. MEK, mitogen-activated protein kinase or extracellular signal-regulated kinase kinase; NMDAR, N-methyl-D-aspartate receptor; GPCR, G proteincoupled receptor; RTK, receptor tyrosine kinase; PKA, protein kinase A; PKC, protein kinase C; SHP2, Src homology 2-containing tyrosine phosphatase.