Pyrroline-5-Carboxylate Reductase 1 (PYCR1)

PYCR1 catalyzes the NAD(P)H-dependent conversion of pyrroline-5-carboxylate to proline. This enzyme may also play a physiologic role in the generation of NADP(+) in some cell types. The protein forms a homopolymer and localizes to the mitochondrion. Alternate splicing results in two transcript variants encoding different isoforms.The 1,810-bp cDNA hybridized to a 1.85-kb mRNA in samples from human cell lines and predicated a 319-amino acid, 33.4-kD protein.PYCR1 protein colocalized with various mitochondrial markers, including delta-1-pyrroline-5-carboxylate synthetase (P5CS), which also belongs to the proline metabolic pathway. Knockdown of the orthologous genes in Xenopus and zebrafish led to epidermal hypoplasia and blistering that was accompanied by a massive increase in apoptosis.