Regulatory subunit of protein phosphatase 1 (PP1c) that acts as a M-Ras/MRAS effector and participates in MAPK pathway activation. Upon M-Ras/MRAS activation, targets PP1c to specifically dephosphorylate the 'Ser-259' inhibitory site of RAF1 kinase and stimulate RAF1 activity at specialized signaling complexes. Interacts with M-Ras/MRAS, and RAF1. Forms a multiprotein complex with Ras (M-Ras/MRAS), Raf (RAF1) and protein phosphatase 1 (PPP1CA, PPP1CB and PPP1CC). Interacts with ERBIN; disrupts the interaction with RAF1 and Ras, leading to prevent activation of the Ras signaling pathway. Specifically binds K-Ras/KRAS, M-Ras/MRAS and N-Ras/NRAS but not H-Ras/HRAS. Interacts with LZTR1. Translocates from cytoplasm to nucleus upon growth factor stimulation. Belongs to the SHOC2 family.