ALG1 Gene: Chitobiosyldiphosphodolichol Beta-Mannosyltransferase
Key enzyme in N-glycosylation; mutations cause congenital disorders of glycosylation (CDG-Ik).
Gene Information Card
| Symbol | ALG1 |
|---|---|
| Full Name | Chitobiosyldiphosphodolichol Beta-Mannosyltransferase |
| Gene Type | Protein coding |
| Chromosomal Location | 16p13.3 |
| NCBI Gene ID | 56052 ncbi.nlm.nih.gov/gene/56052 |
| Ensembl ID | ENSG00000161980 |
| UniProt ID | Q9BT22 |
| OMIM ID | 605907 |
| HGNC ID | 24557 |
| Aliases | HMT-1, HMT1, MAT-1, MAT1, MGC:133276 |
Description
The ALG1 gene encodes a beta-1,4-mannosyltransferase that catalyzes the first mannosylation step in the assembly of the lipid-linked oligosaccharide (LLO) precursor for N-linked glycosylation. This enzyme transfers mannose from GDP-mannose to chitobiosyldiphosphodolichol (GlcNAc2-PP-dolichol) to form Man1GlcNAc2-PP-dolichol. Mutations in ALG1 cause congenital disorder of glycosylation type Ik (CDG-Ik), a multisystem disorder characterized by developmental delay, hypotonia, seizures, and coagulopathy.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Congenital disorder of glycosylation type Ik (CDG-Ik) | Impaired N-glycosylation due to deficient mannosyltransferase activity; reduced LLO intermediate Man1GlcNAc2-PP-dolichol | ClinVar, OMIM |
| ALG1-CDG (CDG-Ik) | Autosomal recessive; loss-of-function mutations lead to underglycosylation of proteins | NCBI Gene, OMIM |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Liver | 12.3 | Medium |
| Brain | 8.7 | Low |
| Heart | 6.5 | Low |
| Kidney | 10.1 | Medium |
| Lung | 7.2 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK293 | 15.4 | High expression |
| HeLa | 9.8 | Medium expression |
| K562 | 6.1 | Low expression |
| HepG2 | 11.2 | Medium expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.773C>T (p.Ser258Leu) | Missense | Common in CDG-Ik | Reduced enzyme activity; impaired mannosylation |
| c.1165G>A (p.Gly389Arg) | Missense | Rare | Loss of function; severe phenotype |
| c.1076_1077del (p.Glu359Glyfs*12) | Frameshift | Rare | Null allele; complete loss of activity |
Mutation functional classification
Loss of Function (LOF)
Most ALG1 mutations are loss-of-function, reducing or abolishing mannosyltransferase activity, leading to underglycosylation.
Gain of Function (GOF)
No gain-of-function mutations reported.
Dominant Negative (DN)
No dominant-negative effects described; disease is autosomal recessive.
View complete mutation data：
Gene Ontology (GO)
Pathways
• N-glycan biosynthesis (KEGG: hsa00510)
• Metabolism of proteins (Reactome: R-HSA-392499)
Protein Summary
ALG1 is a 464-amino acid transmembrane protein localized to the endoplasmic reticulum membrane. It belongs to the glycosyltransferase family 1 and contains a DXD motif essential for catalytic activity. The protein transfers mannose from GDP-mannose to the growing LLO chain. Defects in ALG1 disrupt the early steps of N-glycosylation, leading to accumulation of truncated oligosaccharides and clinical features of CDG-Ik.
Related Services
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|---|---|---|---|---|
| ALG10 Knockout HEK293 Cell Line | EDJ-KQ10257 | Human | 84920 | Details Get a Quote |
| ALG10B Knockout HEK293 Cell Line | EDJ-KQ10409 | Human | 144245 | Details Get a Quote |
| ALG1L2 Knockout HEK293 Cell Line | EDJ-KQ12331 | Human | 644974 | Details Get a Quote |
| ALG12 Knockout HEK293 Cell Line | EDJ-KQ12332 | Human | 79087 | Details Get a Quote |
| ALG12 Knockout A-549 Cell Line | EDJ-KQ41177 | Human | 79087 | Details Get a Quote |
| ALG12 Knockout HCT 116 Cell Line | EDJ-KQ41178 | Human | 79087 | Details Get a Quote |
| ALG12 Knockout HeLa Cell Line | EDJ-KQ41179 | Human | 79087 | Details Get a Quote |
| ALG10 Knockout A-549 Cell Line | EDJ-KQ37474 | Human | 84920 | Details Get a Quote |
| ALG10 Knockout HCT 116 Cell Line | EDJ-KQ37475 | Human | 84920 | Details Get a Quote |
| ALG10 Knockout HeLa Cell Line | EDJ-KQ37476 | Human | 84920 | Details Get a Quote |
| ALG10B Knockout A-549 Cell Line | EDJ-KQ37765 | Human | 144245 | Details Get a Quote |
| ALG10B Knockout HCT 116 Cell Line | EDJ-KQ37766 | Human | 144245 | Details Get a Quote |
| ALG10B Knockout HeLa Cell Line | EDJ-KQ37767 | Human | 144245 | Details Get a Quote |
| ALG1L2 Knockout HeLa Cell Line | EDJ-KQ60578 | Human | 644974 | Details Get a Quote |
| ALG1L2 Knockout A-549 Cell Line | EDJ-KQ69047 | Human | 644974 | Details Get a Quote |
Displaying Records 1 To 15 Of 16 Records
