Gapk1

Gapk1, also known as Glycine cleavage enzyme P-protein 1, is a protein encoded by the GAPK1 gene in humans. This gene is part of the glycine cleavage system, a multi-enzyme complex crucial for the metabolism of glycine. The glycine cleavage system plays a vital role in various metabolic pathways, including amino acid metabolism, one-carbon metabolism, and the synthesis of purines and heme.

The Gapk1 protein itself is a component of the glycine decarboxylase (GDC) complex, which is responsible for the reversible conversion of glycine to serine. This process involves a series of reactions catalyzed by four distinct proteins: P-protein (glycine decarboxylase), H-protein (aminomethyltransferase), L-protein (dihydrolipoyl dehydrogenase), and T-protein (dihydrolipoyl transacetylase). Gapk1 specifically functions as the P-protein, catalyzing the decarboxylation of glycine, releasing carbon dioxide and forming an aminomethyl-N5,N10-methylenetetrahydrofolate intermediate.

Mutations or dysregulation of Gapk1 or other components of the glycine cleavage system can lead to a range of metabolic disorders, collectively known as glycine encephalopathies. These conditions are often characterized by severe neurological impairments, seizures, and intellectual disability. Understanding the function and regulation of Gapk1 is therefore important for comprehending glycine metabolism and its implications for human health and disease.