HAPLN1: Hyaluronan and Proteoglycan Link Protein 1
Key extracellular matrix component in cartilage and neural development
Gene Information Card
| Symbol | HAPLN1 |
|---|---|
| Full Name | Hyaluronan and Proteoglycan Link Protein 1 |
| Gene Type | protein-coding |
| Chromosomal Location | 5q14.3 |
| NCBI Gene ID | 1404 ncbi.nlm.nih.gov/gene/1404 |
| Ensembl ID | ENSG00000145632 |
| UniProt ID | P10915 |
| OMIM ID | 115435 |
| HGNC ID | 4810 |
| Aliases | CRTL1, LP, LP1, proteoglycan link protein |
Description
HAPLN1 encodes hyaluronan and proteoglycan link protein 1, a key extracellular matrix component that stabilizes aggregates of hyaluronic acid and proteoglycans (e.g., aggrecan) in cartilage. It is essential for chondrogenesis, neural crest cell migration, and maintenance of the perineuronal net in the central nervous system. Mutations or dysregulation are linked to skeletal dysplasias and osteoarthritis.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Osteoarthritis | Reduced HAPLN1 expression leads to impaired cartilage matrix stability and increased degradation. | ClinVar, OMIM |
| Spinal cord injury | Upregulation of HAPLN1 in reactive astrocytes contributes to glial scar formation and inhibits axonal regeneration. | NCBI Gene, PubMed |
| Skeletal dysplasia (e.g., spondyloepiphyseal dysplasia) | Loss-of-function mutations disrupt cartilage proteoglycan aggregation, causing abnormal bone development. | OMIM, ClinVar |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Cartilage | 12.5 | High |
| Brain | 8.3 | Medium |
| Spinal cord | 7.1 | Medium |
| Lung | 2.4 | Low |
| Heart | 1.8 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Chondrocytes | 15.2 | Primary cartilage cells |
| Astrocytes | 9.8 | Reactive astrocytes in CNS |
| Fibroblasts | 3.5 | Low expression |
| HEK293 | 0.2 | Negligible |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.256C>T (p.Arg86Cys) | Missense | <0.01% | Reduced protein stability; associated with skeletal dysplasia |
| c.403G>A (p.Gly135Ser) | Missense | <0.01% | Impaired hyaluronan binding; linked to osteoarthritis risk |
| c.1A>G (p.Met1Val) | Start loss | <0.01% | Loss of translation; severe skeletal phenotype |
Mutation functional classification
Loss of Function (LOF)
Missense and start-loss mutations that reduce or abolish protein function, leading to impaired cartilage matrix assembly.
Gain of Function (GOF)
Not reported.
Dominant Negative (DN)
Not reported.
View complete mutation data：
Gene Ontology (GO)
| • extracellular matrix structural constituent | • hyaluronic acid binding |
| • proteoglycan binding | • extracellular space |
| • extracellular matrix | • cartilage development |
| • central nervous system development | • cell adhesion |
Pathways
• ECM-receptor interaction (KEGG: hsa04512)
• Proteoglycans in cancer (KEGG: hsa05205)
• Aggrecan and hyaluronan metabolism (Reactome: R-HSA-216083)
Protein Summary
HAPLN1 encodes a 340-amino-acid protein (link protein 1) that contains an N-terminal signal peptide, a hyaluronan-binding domain, and a C-terminal domain that interacts with proteoglycans. It stabilizes the non-covalent interaction between hyaluronic acid and aggrecan in cartilage, forming large aggregates that provide compressive resistance. In the CNS, it is a component of perineuronal nets and modulates synaptic plasticity.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| HAPLN1 Knockout HEK293 Cell Line | EDJ-KQ4346 | Human | 1404 | Details Get a Quote |
| HAPLN1 Knockout HeLa Cell Line | EDJ-KQ52984 | Human | 1404 | Details Get a Quote |
| HAPLN1 Knockout A-549 Cell Line | EDJ-KQ61451 | Human | 1404 | Details Get a Quote |
| HAPLN1 Knockout HCT 116 Cell Line | EDJ-KQ69948 | Human | 1404 | Details Get a Quote |
Displaying Records 1 To 4 Of 4 Records
