Seroatlas · Human Serome Atlas

LDLRAD4

Low-density lipoprotein receptor class A domain-containing protein 4

Also known as: C18orf1, LRAD4_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
O15165
Gene
LDLRAD4
Ensembl
ENSG00000168675
Chromosome
18
Canonical length
306 aa
Protein class
Predicted intracellular proteins, Predicted membrane proteins
Subcellular location
Vesicles

OverviewNCBI Gene

Enables R-SMAD binding activity. Involved in negative regulation of cell migration; negative regulation of epithelial to mesenchymal transition; and negative regulation of transmembrane receptor protein serine/threonine kinase signaling pathway. Located in early endosome membrane. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

306 residues, UniProt reviewed canonical sequence.

>O15165|LDLRAD4
     1  MPEAGFQATN AFTECKFTCT SGKCLYLGSL VCNQQNDCGD NSDEENCLLV TEHPPPGIFN
    61  SELEFAQIII IVVVVTVMVV VIVCLLNHYK VSTRSFINRP NQSRRREDGL PQEGCLWPSD
   121  SAAPRLGASE IMHAPRSRDR FTAPSFIQRD RFSRFQPTYP YVQHEIDLPP TISLSDGEEP
   181  PPYQGPCTLQ LRDPEQQMEL NRESVRAPPN RTIFDSDLID IAMYSGGPCP PSSNSGISAS
   241  TCSSNGRMEG PPPTYSEVMG HHPGASFLHH QRSNAHRGSR LQFQQNNAES TIVPIKGKDR
   301  KPGNLV

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against LDLRAD4 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
Other membrane
Secreted
No
Transmembrane segments
1
Mean surface accessibility (rSASA)
0.64
Highest tissue expression
56 nTPM

Expression across tissuesHPA

Tissue

  • spinal cord: 56 nTPM
  • thymus: 42 nTPM
  • midbrain: 36 nTPM
  • basal ganglia: 31 nTPM
  • hippocampal formation: 27 nTPM
  • heart muscle: 20 nTPM

Single-cell type

  • choroid plexus epithelial cells: 2,113 nCPM
  • microglia: 1,784 nCPM
  • cone photoreceptor cells: 1,706 nCPM
  • thymocytes: 1,652 nCPM
  • prostatic glandular cells: 1,046 nCPM
  • somatotrophs: 995 nCPM

Immune cell

  • basophil: 13 nTPM
  • neutrophil: 12 nTPM
  • NK-cell: 9.1 nTPM
  • non-classical monocyte: 8.5 nTPM
  • naive CD4 T-cell: 8.1 nTPM
  • intermediate monocyte: 7.7 nTPM

Brain region

  • medulla oblongata: 153 nTPM
  • thalamus: 149 nTPM
  • choroid plexus: 131 nTPM
  • pons: 129 nTPM
  • basal ganglia: 128 nTPM
  • white matter: 127 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)
0.54
gnomAD pLI
0.62
gnomAD missense Z
1.57
DepMap mean gene effect
0.08
DepMap dependency class
none

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 5% 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 LDLRAD4 in the human serome: UniProt-annotated complex subunits plus reported interactors. Each links to its own Seroatlas record.

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads LDLRAD4 as an antibody target. Whether an autoantibody or antibody against LDLRAD4 could matter depends on whether native LDLRAD4 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

LDLRAD4 is annotated as predominantly intracellular. Intracellular proteins are common autoantibody markers, becoming visible to the immune system after cell injury or altered processing, but are usually markers of disease rather than direct drivers.

Annotation status

The present source text does not explicitly label LDLRAD4 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/LDLRAD4. 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).

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