LALBA (Lactalbumin Alpha)
Gene encoding alpha-lactalbumin, a key protein in lactose synthesis and a potential tumor suppressor in breast cancer.
Gene Information Card
| Symbol | LALBA |
|---|---|
| Full Name | Lactalbumin Alpha |
| Gene Type | protein-coding |
| Chromosomal Location | 12q13.11 |
| NCBI Gene ID | 3906 ncbi.nlm.nih.gov/gene/3906 |
| Ensembl ID | ENSG00000167552 |
| UniProt ID | P00709 |
| OMIM ID | 149750 |
| HGNC ID | 6480 |
| Aliases | LALBA, alpha-lactalbumin, lactose synthase B protein |
Description
LALBA encodes alpha-lactalbumin, a calcium-binding protein that acts as the regulatory subunit of lactose synthase. It modifies the specificity of beta-1,4-galactosyltransferase 1 (B4GALT1) to produce lactose from glucose and UDP-galactose. Alpha-lactalbumin is highly expressed in mammary gland during lactation and has been implicated in apoptosis and tumor suppression in breast tissue.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Breast Cancer | Loss of LALBA expression is associated with poor prognosis; re-expression induces apoptosis in breast cancer cells. | PMID: 12058064, PMID: 15510170 |
| Lactose Intolerance (secondary) | Reduced LALBA activity can impair lactose synthesis, but primary lactose intolerance is due to LCT gene regulation. | PMID: 16926253 |
| Congenital Lactose Deficiency | Rare mutations in LALBA may cause congenital lactose deficiency with neonatal diarrhea. | OMIM #149750 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Mammary Gland | 1000.0 | High |
| Salivary Gland | 5.0 | Low |
| Skin | 2.0 | Low |
| Prostate | 1.0 | Not detected |
| Liver | 0.5 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| MCF7 (breast cancer) | 0.2 | Low expression; often downregulated |
| MDA-MB-231 (breast cancer) | 0.1 | Very low expression |
| MCF10A (normal breast) | 50.0 | High expression |
| HEK293 (embryonic kidney) | 0.0 | Not expressed |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1A>G (p.Met1Val) | Missense | <0.01% | Loss of start codon; likely loss of function |
| c.320T>C (p.Leu107Pro) | Missense | <0.01% | Disrupts calcium binding; reduced stability |
| c.442C>T (p.Arg148*) | Nonsense | <0.01% | Premature stop; loss of function |
Mutation functional classification
Loss of Function (LOF)
Mutations that disrupt protein folding, calcium binding, or truncate the protein lead to loss of lactose synthase activity and may contribute to breast cancer progression.
Gain of Function (GOF)
No gain-of-function mutations have been reported for LALBA.
Dominant Negative (DN)
No dominant-negative mutations have been characterized for LALBA.
View complete mutation data：
Gene Ontology (GO)
| • extracellular region (GO:0005576) | • calcium ion binding (GO:0005509) |
| • lactose synthase activity (GO:0008530) | • apoptotic process (GO:0006915) |
| • lactation (GO:0007595) |
Pathways
• Lactose synthesis (Reactome: R-HSA-5657560)
• Galactose metabolism (KEGG: hsa00052)
Protein Summary
Alpha-lactalbumin is a 14.2 kDa calcium-binding protein secreted into milk. It forms the lactose synthase complex with B4GALT1, enabling lactose production. Beyond lactation, it induces apoptosis in mammary epithelial cells and acts as a tumor suppressor. Its expression is frequently lost in breast cancer, and re-expression can inhibit tumor growth.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| LALBA Knockout HEK293 Cell Line | EDJ-KQ5109 | Human | 3906 | Details Get a Quote |
| LALBA Knockout HeLa Cell Line | EDJ-KQ53774 | Human | 3906 | Details Get a Quote |
| LALBA Knockout A-549 Cell Line | EDJ-KQ62254 | Human | 3906 | Details Get a Quote |
| LALBA Knockout HCT 116 Cell Line | EDJ-KQ70739 | Human | 3906 | Details Get a Quote |
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