The function of RCE1 (Ras converting CAAX endopeptidase 1, ENSG00000173653) is as follows. Protease involved in the processing of a variety of prenylated proteins containing the C-terminal CAAX motif, where C is a cysteine modified with an isoprenoid lipid, A is an aliphatic amino acid and X is any C-terminal amino acid. Proteolytically removes the C- terminal three residues of farnesylated and geranylated proteins, leaving the prenylated cysteine as the new C-terminus. Is able to process K-Ras, N-Ras, H-Ras, RAP1B and G-gamma-1 (PubMed:10085068). {ECO:0000269|PubMed:10085068, ECO:0000269|PubMed:11038283, ECO:0000269|PubMed:19188362}.