Seroatlas · Human Serome Atlas

LRFN3

Leucine-rich repeat and fibronectin type-III domain-containing protein 3

Also known as: FIGLER1, LRFN3_HUMAN, MGC2656, SALM4

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

Protein identityUniProt · HPA

UniProt accession
Q9BTN0
Gene
LRFN3
Ensembl
ENSG00000126243
Chromosome
19
Canonical length
628 aa
Protein class
Predicted membrane proteins

OverviewNCBI Gene

Predicted to be involved in regulation of presynapse assembly; regulation of synaptic membrane adhesion; and synaptic membrane adhesion. Predicted to be located in plasma membrane. Predicted to be active in cell surface; glutamatergic synapse; and synaptic membrane. [provided by Alliance of Genome Resources, Apr 2025]

Canonical amino-acid sequenceUniProt

628 residues, UniProt reviewed canonical sequence.

>Q9BTN0|LRFN3
     1  MAILPLLLCL LPLAPASSPP QSATPSPCPR RCRCQTQSLP LSVLCPGAGL LFVPPSLDRR
    61  AAELRLADNF IASVRRRDLA NMTGLLHLSL SRNTIRHVAA GAFADLRALR ALHLDGNRLT
   121  SLGEGQLRGL VNLRHLILSN NQLAALAAGA LDDCAETLED LDLSYNNLEQ LPWEALGRLG
   181  NVNTLGLDHN LLASVPAGAF SRLHKLARLD MTSNRLTTIP PDPLFSRLPL LARPRGSPAS
   241  ALVLAFGGNP LHCNCELVWL RRLAREDDLE ACASPPALGG RYFWAVGEEE FVCEPPVVTH
   301  RSPPLAVPAG RPAALRCRAV GDPEPRVRWV SPQGRLLGNS SRARAFPNGT LELLVTEPGD
   361  GGIFTCIAAN AAGEATAAVE LTVGPPPPPQ LANSTSCDPP RDGDPDALTP PSAASASAKV
   421  ADTGPPTDRG VQVTEHGATA ALVQWPDQRP IPGIRMYQIQ YNSSADDILV YRMIPAESRS
   481  FLLTDLASGR TYDLCVLAVY EDSATGLTAT RPVGCARFST EPALRPCGAP HAPFLGGTMI
   541  IALGGVIVAS VLVFIFVLLM RYKVHGGQPP GKAKIPAPVS SVCSQTNGAL GPTPTPAPPA
   601  PEPAALRAHT VVQLDCEPWG PGHEPVGP

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against LRFN3 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
Cell surface
Secreted
No
Transmembrane segments
1
Mean surface accessibility (rSASA)
0.4
Highest tissue expression
9.4 nTPM

Expression across tissuesHPA

Tissue

  • pituitary gland: 9.4 nTPM
  • cerebral cortex: 9 nTPM
  • ovary: 8.5 nTPM
  • blood vessel: 8.2 nTPM
  • endometrium: 7.9 nTPM
  • cervix: 6.9 nTPM

Single-cell type

  • hepatic stellate cells: 19 nCPM
  • pancreatic islet cells: 10 nCPM
  • alveolar cells type 1: 8.5 nCPM
  • prostatic club cells: 8.2 nCPM
  • foveolar cells: 8 nCPM
  • salivary duct cells: 7.8 nCPM

Immune cell

  • gdT-cell: 0.5 nTPM
  • MAIT T-cell: 0.5 nTPM
  • memory CD8 T-cell: 0.5 nTPM
  • memory CD4 T-cell: 0.4 nTPM
  • naive CD4 T-cell: 0.3 nTPM
  • T-reg: 0.3 nTPM

Brain region

  • cerebral cortex: 25 nTPM
  • cerebellum: 22 nTPM
  • hippocampal formation: 21 nTPM
  • amygdala: 21 nTPM
  • basal ganglia: 18 nTPM
  • thalamus: 18 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)
0.27
gnomAD pLI
0.97
gnomAD missense Z
2.24
DepMap mean gene effect
-0.05
DepMap dependency class
selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 7% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads LRFN3 as an antibody target. Whether an autoantibody or antibody against LRFN3 could matter depends on whether native LRFN3 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

LRFN3 is annotated at the cell surface, where native LRFN3 is exposed to circulating antibodies and is a prime autoantibody target that could block, deplete, or overstimulate it.

Annotation status

The present source text does not explicitly label LRFN3 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/LRFN3. Study-independent annotations aggregated from UniProt, Human Protein Atlas, PubMed, IEDB, Pfam, InterPro, Gene Ontology, AlphaFold, gnomAD, DepMap, ClinVar, TCGA. Catalog release seroatlas-reviewed-human-uniprot-20260313.

Seroatlas is the reference for exploring autoantibody and antibody serology at the human-protein level: the autoreactome and human serome, multiplex serology (HuProt, HuScan, VirScan, PhIP-Seq).

© 2026 · Seroatlas, Discover Oregon LLC · Terms of use

Loading the interactive Seroatlas protein explorer...