Seroatlas · Human Serome Atlas

ALAD

Delta-aminolevulinic acid dehydratase

Also known as: ALADH, HEM2_HUMAN, PBGS

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

Protein identityUniProt · HPA

UniProt accession
P13716
Gene
ALAD
Ensembl
ENSG00000148218
Chromosome
9
Canonical length
330 aa
Protein class
Disease related genes, Enzymes, FDA approved drug targets, Human disease related genes, Metabolic proteins, Plasma proteins, Predicted intracellular proteins
Subcellular location
Cytosol
Quaternary structure
Homooctamer

OverviewNCBI Gene

The ALAD enzyme is composed of 8 identical subunits and catalyzes the condensation of 2 molecules of delta-aminolevulinate to form porphobilinogen (a precursor of heme, cytochromes and other hemoproteins). ALAD catalyzes the second step in the porphyrin and heme biosynthetic pathway; zinc is essential for enzymatic activity. ALAD enzymatic activity is inhibited by lead and a defect in the ALAD structural gene can cause increased sensitivity to lead poisoning and acute hepatic porphyria. Alternative splicing of this gene results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Dec 2015]

Canonical amino-acid sequenceUniProt

330 residues, UniProt reviewed canonical sequence.

>P13716|ALAD
     1  MQPQSVLHSG YFHPLLRAWQ TATTTLNASN LIYPIFVTDV PDDIQPITSL PGVARYGVKR
    61  LEEMLRPLVE EGLRCVLIFG VPSRVPKDER GSAADSEESP AIEAIHLLRK TFPNLLVACD
   121  VCLCPYTSHG HCGLLSENGA FRAEESRQRL AEVALAYAKA GCQVVAPSDM MDGRVEAIKE
   181  ALMAHGLGNR VSVMSYSAKF ASCFYGPFRD AAKSSPAFGD RRCYQLPPGA RGLALRAVDR
   241  DVREGADMLM VKPGMPYLDI VREVKDKHPD LPLAVYHVSG EFAMLWHGAQ AGAFDLKAAV
   301  LEAMTAFRRA GADIIITYYT PQLLQWLKEE

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against ALAD 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
Intracellular
Secreted
No
Transmembrane segments
0
Mean surface accessibility (rSASA)
0.23
Highest tissue expression
196 nTPM

Expression across tissuesHPA

Tissue

  • liver: 196 nTPM
  • adrenal gland: 148 nTPM
  • spinal cord: 111 nTPM
  • midbrain: 105 nTPM
  • salivary gland: 93 nTPM
  • bone marrow: 78 nTPM

Single-cell type

  • erythrocyte progenitors: 311 nCPM
  • adrenal cortex cells: 172 nCPM
  • esophageal apical cells: 110 nCPM
  • esophageal suprabasal cells: 104 nCPM
  • megakaryocyte-erythroid progenitors: 92 nCPM
  • hepatocytes: 84 nCPM

Immune cell

  • eosinophil: 24 nTPM
  • non-classical monocyte: 18 nTPM
  • intermediate monocyte: 16 nTPM
  • myeloid DC: 15 nTPM
  • classical monocyte: 14 nTPM
  • gdT-cell: 11 nTPM

Brain region

  • medulla oblongata: 107 nTPM
  • midbrain: 102 nTPM
  • thalamus: 100 nTPM
  • basal ganglia: 100 nTPM
  • white matter: 100 nTPM
  • spinal cord: 97 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about ALAD.

Disease | AllUniProt

Conditions ALAD is implicated in, by any mechanism.

Disease | GeneticClinVar

6 pathogenic / likely-pathogenic of 215 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

  • Porphobilinogen synthase deficiency

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)
0.87
gnomAD pLI
0
gnomAD missense Z
1.23
DepMap mean gene effect
-0.08
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

  • Aldolase-type TIM barrel
  • Delta-aminolevulinic acid dehydratase
  • Delta-aminolevulinic acid dehydratase, active site
  • Delta-aminolevulinic acid dehydratase

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

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

ALAD 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 ALAD as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/ALAD. 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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