MAN1B1
Mannosidase Alpha Class 1B Member 1
Gene Information Card
| Symbol | MAN1B1 |
|---|---|
| Full Name | Mannosidase Alpha Class 1B Member 1 |
| Gene Type | protein-coding |
| Chromosomal Location | 9q34.3 |
| NCBI Gene ID | 11253 ncbi.nlm.nih.gov/gene/11253 |
| Ensembl ID | ENSG00000136869 |
| UniProt ID | Q9UKM7 |
| OMIM ID | 604346 |
| HGNC ID | 6823 |
| Aliases | ERManI, MAN1B, MANS, FLJ10848 |
Description
MAN1B1 encodes the endoplasmic reticulum (ER) mannosidase I, which removes a specific mannose residue from N-glycans during glycoprotein quality control. This enzyme is critical for the ER-associated degradation (ERAD) pathway, targeting misfolded glycoproteins for degradation. Loss-of-function mutations lead to MAN1B1-congenital disorder of glycosylation (MAN1B1-CDG), characterized by intellectual disability, hypotonia, and dysmorphic features.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| MAN1B1-CDG (Congenital Disorder of Glycosylation Type II) | Loss-of-function mutations impair ER mannosidase activity, disrupting N-glycan trimming and ERAD, leading to accumulation of misfolded glycoproteins. | ClinVar, OMIM #604346 |
| Intellectual Disability | Defective glycoprotein quality control in neurons affects synaptic function and development. | OMIM, PubMed studies |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Liver | 12.5 | Medium |
| Brain | 8.3 | Medium |
| Kidney | 7.1 | Medium |
| Testis | 6.9 | Medium |
| Lung | 5.2 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HepG2 | 14.2 | Hepatocellular carcinoma line |
| SH-SY5Y | 9.8 | Neuroblastoma line |
| HEK293 | 8.5 | Embryonic kidney line |
| HeLa | 6.1 | Cervical carcinoma line |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1742G>A (p.Arg581His) | Missense | Rare | Loss of enzymatic activity; associated with MAN1B1-CDG |
| c.1000C>T (p.Arg334*) | Nonsense | Rare | Premature stop; loss of function |
| c.1486_1487del (p.Leu496Glufs*5) | Frameshift | Rare | Truncated protein; loss of function |
Mutation functional classification
Loss of Function (LOF)
Most reported mutations are loss-of-function, reducing or abolishing ER mannosidase activity, leading to MAN1B1-CDG.
Gain of Function (GOF)
No gain-of-function mutations reported.
Dominant Negative (DN)
No dominant-negative mutations reported.
View complete mutation data：
Gene Ontology (GO)
| • alpha-mannosidase activity | • endoplasmic reticulum |
| • N-glycan processing | • ER-associated protein catabolic process |
| • carbohydrate metabolic process |
Pathways
• N-Glycan biosynthesis
• ERAD pathway
• Protein processing in endoplasmic reticulum
Protein Summary
MAN1B1 is a 699-amino acid type II transmembrane protein localized to the ER. It functions as an alpha-1,2-mannosidase that cleaves a single mannose residue from Man9GlcNAc2 to produce Man8GlcNAc2, a key step in glycoprotein quality control. The protein contains a catalytic domain facing the ER lumen and a short cytoplasmic tail. Defects in this enzyme cause accumulation of misfolded glycoproteins and lead to MAN1B1-CDG.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| MAN1B1 Knockout HEK293 Cell Line | EDJ-KQ7351 | Human | 11253 | Details Get a Quote |
| MAN1B1 Knockout A-549 Cell Line | EDJ-KQ31084 | Human | 11253 | Details Get a Quote |
| MAN1B1 Knockout HCT 116 Cell Line | EDJ-KQ32459 | Human | 11253 | Details Get a Quote |
| MAN1B1 Knockout HeLa Cell Line | EDJ-KQ32460 | Human | 11253 | Details Get a Quote |
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