Binding of RASGRF1 oligomers (Anborgh et al. 1999) to calcium-activated calmodulin (CALM1:4xCa2+) stimulates GDP to GTP exchange on RAS, resulting in RAS activation (Farnsworth et al. 1995). Binding of RASGRF1 to the GluN2B (GRIN2B, NR2B) subunit of NMDA receptors is needed for activation of RAS downstream of NDMA receptor activation (Krapivinsky et al. 2003).
Activated CaMKII can contribute to activation of RAS/RAF/MAPK signaling by phosphorylation of RAF1 (Salzano et al. 2012).