Pyrroline-5-carboxylate reductase 1, mitochondrial (PYCR1)

Pyrroline-5-carboxylate reductase 1, mitochondrial (PYCR1), is a mitochondrial oxidoreductase enzyme that catalyzes the NAD(P)H-dependent conversion of pyrroline-5-carboxylate (P5C) to L-proline—the final step in proline biosynthesis[1][4][5][6]. PYCR1 is essential for cellular amino acid metabolism, redox homeostasis, and mitochondrial integrity[1][3]. Upregulated in several cancers, PYCR1 supports tumor cell proliferation, stress resistance, and extracellular matrix production[2][3][7]. Loss-of-function mutations in PYCR1 cause autosomal recessive cutis laxa by impairing collagen synthesis[3][5]. Recent studies highlight PYCR1 as a potential prognostic biomarker and emerging therapeutic target for malignancies, especially where proline metabolism is dysregulated[2][3][7].

Other names

Pyrroline-5-carboxylate reductase 1, mitochondrialPYCR1P5C reductase 1P5CR 1P5CARCL2BARCL3BPIG45PP222PRO3PYCRproliferation-inducing protein 45

Targeted inhibition reduces proline biosynthesis, impeding cancer cell growth and invasiveness[2][3]. Inhibition can alter redox balance and sensitize cells to oxidative stress and chemotherapy[2].