Seroatlas · Human Serome Atlas

LCN1

Lipocalin-1

Also known as: LCN1_HUMAN, MGC71975, PMFA, TLC, TP, VEGP

Cross-references: UniProt · Ensembl · Human Protein Atlas · GeneCards · NCBI Gene

Protein identityUniProt · HPA

UniProt accession: P31025
Gene: LCN1
Ensembl: ENSG00000160349
Chromosome: 9
Canonical length: 176 aa
Protein class: Cancer-related genes, Plasma proteins, Predicted secreted proteins
Secretome location: Secreted in other tissues
Quaternary structure: Homodimer

OverviewNCBI Gene

This gene encodes a member of the lipocalin family of small secretory proteins. Lipocalins are extracellular transport proteins that bind to a variety of hydrophobic ligands. The encoded protein is the primary lipid binding protein in tears and is overproduced in response to multiple stimuli including infection and stress. The encoded protein may be a marker for chromosome aneuploidy as well as an autoantigen in Sjogren's syndrome. Alternatively spliced transcript variants encoding multiple isoforms have been observed for this gene, and two pseudogenes of this gene are also located on the long arm of chromosome 9. [provided by RefSeq, Nov 2011]

Canonical amino-acid sequenceUniProt

176 residues, UniProt reviewed canonical sequence.

>P31025|LCN1
     1  MKPLLLAVSL GLIAALQAHH LLASDEEIQD VSGTWYLKAM TVDREFPEMN LESVTPMTLT
    61  TLEGGNLEAK VTMLISGRCQ EVKAVLEKTD EPGKYTADGG KHVAYIIRSH VKDHYIFYCE
   121  GELHGKPVRG VKLVGRDPKN NLEALEDFEK AAGARGLSTE SILIPRQSET CSPGSD

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against LCN1 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): 0.33
Highest tissue expression: 13 nTPM

Expression across tissuesHPA

Tissue

esophagus: 13 nTPM
seminal vesicle: 7.5 nTPM
hippocampal formation: 1.9 nTPM
fallopian tube: 1.8 nTPM
pituitary gland: 1.8 nTPM
blood vessel: 1.1 nTPM

Single-cell type

lacrimal acinar cells: 24,712 nCPM
conjunctival goblet cells: 503 nCPM
neutrophils: 258 nCPM
monocytes: 62 nCPM
plasma cells: 45 nCPM
nk-cells: 31 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

hippocampal formation: 1.4 nTPM
cerebral cortex: 0.7 nTPM
white matter: 0.5 nTPM
amygdala: 0.1 nTPM
basal ganglia: 0.1 nTPM
cerebellum: 0.1 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about LCN1.

Disease | ImmuneIEDB

Conditions an epitope on LCN1 was assayed in.

allergic asthma T cell

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): 1.83
gnomAD pLI: 0
gnomAD missense Z: -0.76
DepMap mean gene effect: -0.15
DepMap dependency class: selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 2% 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

InteractionsUniProt · HPA

Protein binding partners of LCN1 in the human serome: UniProt-annotated complex subunits plus reported interactors. Each links to its own Seroatlas record.

LMBR1L

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads LCN1 as an antibody target. Whether an autoantibody or antibody against LCN1 could matter depends on whether native LCN1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

LCN1 is annotated as secreted, so native LCN1 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.

Source-annotated serology context

The source annotations explicitly mention antibody, autoantibody, autoantigen, or autoimmune context. This is biological context, not study-specific reactivity.

The encoded protein may be a marker for chromosome aneuploidy as well as an autoantigen in Sjogren's syndrome.

Loading the interactive Seroatlas protein explorer...