HAPLN1
Hyaluronan and proteoglycan link protein 1
Also known as: CRTL1, HPLN1_HUMAN
Cross-references: UniProt · Ensembl · Human Protein Atlas · GeneCards · NCBI Gene
Protein identityUniProt · HPA
- UniProt accession
- P10915
- Gene
- HAPLN1
- Ensembl
- ENSG00000145681
- Chromosome
- 5
- Canonical length
- 354 aa
- Protein class
- Predicted secreted proteins
- Subcellular location
- Vesicles
- Secretome location
- Secreted to extracellular matrix
OverviewNCBI Gene
Predicted to enable hyaluronic acid binding activity. Predicted to be an extracellular matrix structural constituent conferring compression resistance. Predicted to be involved in central nervous system development and skeletal system development. Located in collagen-containing extracellular matrix. [provided by Alliance of Genome Resources, Apr 2025]
Canonical amino-acid sequenceUniProt
354 residues, UniProt reviewed canonical sequence.
>P10915|HAPLN1
1 MKSLLLLVLI SICWADHLSD NYTLDHDRAI HIQAENGPHL LVEAEQAKVF SHRGGNVTLP
61 CKFYRDPTAF GSGIHKIRIK WTKLTSDYLK EVDVFVSMGY HKKTYGGYQG RVFLKGGSDS
121 DASLVITDLT LEDYGRYKCE VIEGLEDDTV VVALDLQGVV FPYFPRLGRY NLNFHEAQQA
181 CLDQDAVIAS FDQLYDAWRG GLDWCNAGWL SDGSVQYPIT KPREPCGGQN TVPGVRNYGF
241 WDKDKSRYDV FCFTSNFNGR FYYLIHPTKL TYDEAVQACL NDGAQIAKVG QIFAAWKILG
301 YDRCDAGWLA DGSVRYPISR PRRRCSPTEA AVRFVGFPDK KHKLYGVYCF RAYNLocalizationUniProt · AlphaFold · HPA
Whether an antibody against HAPLN1 can act on the native protein depends on physical access: surface and secreted proteins are reachable by circulating antibodies, intracellular proteins usually are not.
- Antibody reachability
- Secreted
- Secreted
- Yes
- Transmembrane segments
- 0
- Mean surface accessibility (rSASA)
- 0.31
- Highest tissue expression
- 70 nTPM
Expression across tissuesHPA
Tissue
- placenta: 70 nTPM
- rectum: 10 nTPM
- small intestine: 10 nTPM
- colon: 8.5 nTPM
- cerebral cortex: 6.9 nTPM
- duodenum: 6.8 nTPM
Single-cell type
- fibroblasts: 108 nCPM
- pericytes: 24 nCPM
- oligodendrocyte progenitor cells: 17 nCPM
- granulosa cells: 15 nCPM
- brain inhibitory neurons: 14 nCPM
- migrating cytotrophoblasts: 5.5 nCPM
Immune cell
- basophil: 0 nTPM
- classical monocyte: 0 nTPM
- eosinophil: 0 nTPM
- gdT-cell: 0 nTPM
- intermediate monocyte: 0 nTPM
- MAIT T-cell: 0 nTPM
Brain region
- hypothalamus: 6.2 nTPM
- cerebellum: 2.9 nTPM
- cerebral cortex: 2.7 nTPM
- medulla oblongata: 2.6 nTPM
- midbrain: 2.6 nTPM
- basal ganglia: 2.2 nTPM
Genetic constraint and essentialitygnomAD · DepMap
Does the body need this protein intact? Low LOEUF or a strong DepMap dependency means loss or blockade of the protein is likely to be felt.
- gnomAD LOEUF (loss-of-function intolerance)
- 0.49
- gnomAD pLI
- 0.6
- gnomAD missense Z
- 0.41
- DepMap mean gene effect
- -0.06
- DepMap dependency class
- selective
Cancer expressionTCGA
Across TCGA tumor cohorts, this protein is over-expressed in roughly 4% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).
OntologyGO
Biological processes
Molecular functions
Cellular components
Protein domainsUniProt · Pfam · InterPro
KeywordsUniProt
Antibody and autoantibody relevanceSeroatlas analysis
Seroatlas reads HAPLN1 as an antibody target. Whether an autoantibody or antibody against HAPLN1 could matter depends on whether native HAPLN1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.
HAPLN1 is annotated as secreted, so native HAPLN1 circulates and is directly accessible to antibodies. Secreted and cell-surface proteins are the autoantibody targets most likely to act like drugs, blocking or depleting the native protein.
Annotation status
The present source text does not explicitly label HAPLN1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.
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