Converts the prephenate produced from the shikimate-chorismate pathway into phenylalanine (PubMed:17726025). Together with GCR1 and GPA1, required for blue light-mediated synthesis of phenylpyruvate and subsequently of phenylalanine (Phe), in etiolated seedlings (PubMed:16415218). H(+) + L-arogenate = CO2 + H2O + L-phenylalanine Amino-acid biosynthesis; L-phenylalanine biosynthesis; L-phenylalanine from L-arogenate: step 1/1. May interact with GPA1. Expressed in roots, leaves, stems, flowers and siliques. Lack of Phe and Tyr accumulation after blue light irradiation of etiolated seedlings. Has no detectable prehenate dehydratase activity. Was reported to be a cytosolic prephenate dehydratase interacting with a G-protein alpha-subunit.