GANAB: Glucosidase II Alpha Subunit
A key enzyme in glycoprotein processing and associated with polycystic kidney disease
Gene Information Card
| Symbol | GANAB |
|---|---|
| Full Name | Glucosidase II Alpha Subunit |
| Gene Type | protein-coding |
| Chromosomal Location | 11q12.3 |
| NCBI Gene ID | 23193 ncbi.nlm.nih.gov/gene/23193 |
| Ensembl ID | ENSG00000149131 |
| UniProt ID | Q14697 |
| OMIM ID | 104160 |
| HGNC ID | 4138 |
| Aliases | G2AN, GIIA, GLU2A, KIAA0088 |
Description
The GANAB gene encodes the alpha subunit of glucosidase II, an endoplasmic reticulum (ER) enzyme that cleaves the two innermost glucose residues from N-linked glycoproteins. This processing step is critical for proper glycoprotein folding, quality control, and trafficking. Mutations in GANAB are associated with autosomal dominant polycystic kidney disease (ADPKD) and polycystic liver disease.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Autosomal dominant polycystic kidney disease (ADPKD) | Loss-of-function mutations in GANAB impair glucosidase II activity, leading to defective maturation of polycystin-1 (PC1) and polycystin-2 (PC2), key proteins in renal tubular cilia, resulting in cyst formation. | ClinVar, OMIM |
| Polycystic liver disease | Similar mechanism as ADPKD; defective glycoprotein processing affects hepatocyte function and bile duct development. | OMIM |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Liver | 12.5 | Medium |
| Kidney | 8.3 | Medium |
| Pancreas | 7.1 | Medium |
| Small intestine | 6.9 | Medium |
| Brain | 5.2 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HepG2 | 14.2 | Hepatocellular carcinoma cell line |
| HEK 293 | 10.5 | Embryonic kidney cells |
| A549 | 8.8 | Lung carcinoma cells |
| K562 | 6.1 | Leukemia cells |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.796C>T (p.Arg266*) | Nonsense | Rare | Loss of function; truncation of glucosidase II alpha subunit |
| c.1072G>A (p.Gly358Arg) | Missense | Rare | Impaired enzymatic activity; associated with ADPKD |
| c.1462_1463del (p.Leu488Valfs*2) | Frameshift | Rare | Loss of function; premature stop codon |
Mutation functional classification
Loss of Function (LOF)
Most GANAB mutations are loss-of-function, reducing glucosidase II activity and impairing glycoprotein quality control.
Gain of Function (GOF)
No gain-of-function mutations reported.
Dominant Negative (DN)
Some missense mutations may exert dominant-negative effects by interfering with the wild-type enzyme complex.
View complete mutation data：
Gene Ontology (GO)
| • endoplasmic reticulum (GO:0005783) | • mannosyl-oligosaccharide glucosidase activity (GO:0004573) |
| • protein N-linked glycosylation (GO:0006487) | • ER-associated misfolded protein catabolic process (GO:0030433) |
Pathways
• REACT:21369 - N-glycan trimming in the ER
• REACT:21370 - Quality control of glycoprotein folding
• KEGG:00510 - N-Glycan biosynthesis
Protein Summary
Glucosidase II alpha subunit (GANAB) is a 966-amino acid protein localized to the endoplasmic reticulum. It forms a heterodimeric complex with the beta subunit (PRKCSH) to catalyze the sequential removal of two glucose residues from N-linked oligosaccharides. This step is essential for glycoprotein folding and for the recognition of misfolded proteins by the ER quality control machinery. Defects in GANAB lead to accumulation of improperly processed glycoproteins, contributing to cystogenesis in kidney and liver.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| GANAB Knockout HEK293 Cell Line | EDJ-KQ2622 | Human | 23193 | Details Get a Quote |
| GANAB Knockout HCT 116 Cell Line | EDJ-KQ21990 | Human | 23193 | Details Get a Quote |
| GANAB Knockout A-549 Cell Line | EDJ-KQ23354 | Human | 23193 | Details Get a Quote |
| GANAB Knockout HeLa Cell Line | EDJ-KQ23355 | Human | 23193 | Details Get a Quote |
