PIGK

Chr 1p31.1

phosphatidylinositol glycan anchor biosynthesis class K

Aliases:: hGPI8, GPI8, PIG-K
MANE:: ENST00000370812.8

OMIM: 605087 ↗NCBI: 10026 ↗Ensembl ↗

Annotations refreshed 9 hours ago.

Predicted protein structure

AlphaFold predicted structure

PIGK · Q92643

v62025-08-01

Predicted Aligned Error matrix for PIGK — diagonal shows residue index, colour shows pairwise prediction confidence (lower is better) — Predicted Aligned Error

Mean pLDDT

85.1/ 100

Confident

395 residues

Confidence breakdown

Very high(≥ 90)64%
Confident(70–90)12%
Low(50–70)19%
Very low(< 50)5%

Open interactive 3D viewer

AlphaFold (Jumper et al., 2021) · CC BY 4.0

Clinical relevance (Genomics England PanelApp)

Diagnostic Grade (Green)

DDG2P
BIALLELIC, autosomal or pseudoautosomal
Early onset or syndromic epilepsy
BIALLELIC, autosomal or pseudoautosomal
Fetal anomalies
BIALLELIC, autosomal or pseudoautosomal
Intellectual disability
BIALLELIC, autosomal or pseudoautosomal

Disease associations (Open Targets)

neurodevelopmental disorder with hypotonia and cerebellar atrophy, with or without seizures
0.79
neurodegenerative disease
0.48
circadian rhythm
0.37
Abnormal pupillary function
0.29
ocular hypotension
0.29
Abnormal nasolacrimal system morphology
0.29
Abnormality of limbs
0.29
jaw disease
0.27
Abnormality of the immune system
0.26
hereditary disease
0.19

Score is the Open Targets composite evidence score (0-1). Higher = stronger gene-disease association.

Protein function (UniProt)

GPI-anchor transamidase

Catalytic subunit of the glycosylphosphatidylinositol-anchor (GPI-anchor) transamidase (GPI-T) complex that catalyzes the formation of the linkage between a proprotein and a GPI-anchor and participates in GPI anchored protein biosynthesis (PubMed:10793132, PubMed:11483512, PubMed:12582175, PubMed:34576938, PubMed:35165458, PubMed:35551457, PubMed:37684232, PubMed:9356492). Recognizes diverse proproteins at a C-terminal signal peptide (CSP) region that lacks consensus sequence and replaces it with a GPI-anchor via a transamidation reaction (PubMed:35165458, PubMed:35551457, PubMed:37684232). Transamidation catalysis reaction follows a two-phase mechanism (PubMed:37684232). In the acyl-enzyme phase, the carbonyl group of the proproteins's omega-site undergoes a nucleophilic attack forming an enzyme-substrate thioester bond (PubMed:37684232). Followed by a general acid catalysis that allows CSP releasing, regenerating the carbonyl, and forming the acyl-enzyme intermediate (PubMed:37684232). In the GPI-anchor attachment phase, the amino group of the GPI-anchor's ethanolamine phosphate, the one on third mannose (EtNP3), mediates a nucleophilic attack on the carbonyl of the acyl-enzyme intermediate, replacing the CSP, allowing GPI-anchor attachment to the omega-residue, therefore forming the product and freeing the enzyme (PubMed:37684232)