EXTL2: Exostosin Like Glycosyltransferase 2
A key enzyme in heparan sulfate biosynthesis and its role in developmental disorders and cancer
Gene Information Card
| Symbol | EXTL2 |
|---|---|
| Full Name | Exostosin Like Glycosyltransferase 2 |
| Gene Type | Protein coding |
| Chromosomal Location | 1p21.2 |
| NCBI Gene ID | 2135 ncbi.nlm.nih.gov/gene/2135 |
| Ensembl ID | ENSG00000162692 |
| UniProt ID | Q9UBQ6 |
| OMIM ID | 602411 |
| HGNC ID | 3515 |
| Aliases | EXTL2, EXT-like 2, EXTL, EXTL2_HUMAN |
Description
EXTL2 encodes a member of the exostosin (EXT) family of glycosyltransferases. The protein is a type II transmembrane glycoprotein localized to the Golgi apparatus and functions as an alpha-1,4-N-acetylhexosaminyltransferase involved in the initiation and elongation of heparan sulfate chains. It transfers N-acetylglucosamine to the tetrasaccharide linker region during heparan sulfate biosynthesis. Mutations in EXTL2 are associated with hereditary multiple exostoses and certain cancers.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Hereditary Multiple Exostoses (HME) | Loss-of-function mutations impair heparan sulfate elongation, leading to abnormal bone growth | OMIM #133701 |
| Exostosis | Defective glycosyltransferase activity disrupts cartilage development | ClinVar |
| Colorectal Cancer | Somatic mutations and altered expression contribute to tumor progression | COSMIC |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Liver | 8.2 | Medium |
| Kidney | 6.5 | Medium |
| Brain | 3.1 | Low |
| Heart | 2.8 | Low |
| Lung | 4.0 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HepG2 | 7.9 | Hepatocellular carcinoma cell line |
| HEK 293 | 5.2 | Embryonic kidney cells |
| A549 | 3.8 | Lung carcinoma cells |
| MCF7 | 2.1 | Breast cancer cells |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1015C>T (p.Arg339*) | Nonsense | 0.01% | Loss of function; truncated protein |
| c.1246G>A (p.Gly416Arg) | Missense | 0.005% | Reduced enzymatic activity |
| c.1489_1490del (p.Leu497fs) | Frameshift | 0.002% | Loss of function |
Mutation functional classification
Loss of Function (LOF)
Nonsense and frameshift mutations that truncate or destabilize the protein, reducing heparan sulfate synthesis.
Gain of Function (GOF)
Not reported in EXTL2.
Dominant Negative (DN)
Not reported in EXTL2.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Heparan sulfate biosynthesis (Reactome: R-HSA-2022928)
• Glycosaminoglycan metabolism (KEGG: hsa00532)
Protein Summary
EXTL2 is a 330-amino acid type II transmembrane protein localized to the Golgi. It catalyzes the transfer of N-acetylglucosamine to the tetrasaccharide linker during heparan sulfate chain initiation. The protein contains a conserved glycosyltransferase domain and is essential for normal heparan sulfate production. Loss-of-function mutations lead to reduced heparan sulfate levels, contributing to exostosis formation and tumorigenesis.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| EXTL2 Knockout HEK293 Cell Line | EDJ-KQ4565 | Human | 2135 | Details Get a Quote |
| EXTL2 Knockout A-549 Cell Line | EDJ-KQ27212 | Human | 2135 | Details Get a Quote |
| EXTL2 Knockout HCT 116 Cell Line | EDJ-KQ27213 | Human | 2135 | Details Get a Quote |
| EXTL2 Knockout HeLa Cell Line | EDJ-KQ27214 | Human | 2135 | Details Get a Quote |
