Palmitoyl Protein Thioesterase 1 (PPT1)

PPT1 is a small glycoprotein involved in the catabolism of lipid-modified proteins during lysosomal degradation. The encoded enzyme removes thioester-linked fatty acyl groups such as palmitate from cysteine residues. Defects in this gene are a cause of infantile neuronal ceroid lipofuscinosis 1 (CLN1, or INCL) and neuronal ceroid lipofuscinosis 4 (CLN4). Two transcript variants encoding different isoforms have been found for this gene.The cDNA predicted a 306-amino acid polypeptide that contains a 25-amino acid signal peptide, 3 N-linked glycosylation sites, and consensus motifs characteristic of thioesterases. Northern blot analysis revealed ubiquitous expression of a single 2.5-kb mRNA, with highest expression in lung, brain, and heart.