Maintenance of cellular vitamin B₆ levels and mitochondrial oxidative function depend on pyridoxal 5'-phosphate homeostasis protein.

ABSTRACT: Recently, biallelic variants in PLPBP coding for pyridoxal 5'-phosphate homeostasis protein (PLPHP) were identified as a novel cause of early-onset vitamin B₆-dependent epilepsy. The molecular function and precise role of PLPHP in vitamin B₆ metabolism are not well understood. To address these questions, we used PLPHP-deficient patient skin fibroblasts and HEK293 cells and YBL036C (PLPHP ortholog)-deficient yeast. We showed that independent of extracellular B₆ vitamer type (pyridoxine, pyridoxamine, or pyridoxal), intracellular pyridoxal 5'-phosphate (PLP) was lower in PLPHP-deficient fibroblasts and HEK293 cells than controls. Culturing cells with pyridoxine or pyridoxamine led to the concentration-dependent accumulation of pyridoxine 5'-phosphate and pyri

SUBMITTER: Ciapaite J 

PROVIDER: S-EPMC10463200 | biostudies-literature | 2023 Sep

REPOSITORIES: biostudies-literature