PGAP1

Family: PGAP1

Block: X

Parent Family: No family

Comment

Post-GPI (Glycophosphatidylinositol; Glycosylphosphatidylinositol) attachment to proteins factor 1. The sequences found in this family are similar to PGAP1 (Q765A7_RAT). This is an endoplasmic reticulum membrane protein with a catalytic serine containing motif that is conserved in a number of lipases. PGAP1 functions as a GPI inositol-deacylase; this deacylation is important for the efficient transport of GPI-anchored proteins from the endoplasmic reticulum to the Golgi body. This family consists of several hypothetical bacterial proteins of unknown function. Members of this family have an alpha/beta hydrolase fold. The type VI lipase effectors Tle1-Tle5 secreted by the bacterial type VI secretion system (T6SS) have recently been identified as antibacterial effectors that hydrolyze membrane phospholipids. The Tle1-4 display phospholipase A1 and A2 (PLA1) (PLA2) activities. Tle1 belongs to Duf_2235 family (now T6SS-TLE1), TLE2 to Lipase_3, TLE3 to alpha/ beta hydrolase (now T6SS-TLE3) and here Tle4 belongs to PGAP1. There are two human genes in this family. One is SERAC1. Mutations of SERAC1 causes MEGDEL syndrome, a recessive disorder of dystonia and deafness with encephalopathy and Leigh-like syndrome, impaired oxidative phosphorylation and 3-methylglutaconic aciduria. Clinical features included psychomotor retardation, recurrent infections in infancy, hypoglycemia, spasticity, dystonia, sensorineural deafness, brain atrophy, and lesions on brain imaging. Laboratory studies showed increased serum lactate and alanine, urinary 3-MGA, mitochondrial oxidative phosphorylation defects, abnormal mitochondria, an abnormal phosphatidylglycerol and cardiolipin spectrum in fibroblasts, and abnormal accumulation of unesterified cholesterol within cells.The other is PGAP1 Mutations in PGAP1 causes Mental retardation, autosomal recessive 42 MRT42