Seroatlas · Human Serome Atlas

SMPD1

Sphingomyelin phosphodiesterase

Also known as: ASM, ASM_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
P17405
Gene
SMPD1
Ensembl
ENSG00000166311
Chromosome
11
Canonical length
631 aa
Protein class
Disease related genes, Enzymes, Human disease related genes, Metabolic proteins, Potential drug targets, Predicted intracellular proteins, Predicted secreted proteins
Secretome location
Secreted to blood

OverviewNCBI Gene

The protein encoded by this gene is a lysosomal acid sphingomyelinase that converts sphingomyelin to ceramide. The encoded protein also has phospholipase C activity. Defects in this gene are a cause of Niemann-Pick disease type A (NPA) and Niemann-Pick disease type B (NPB). Multiple transcript variants encoding different isoforms have been identified. [provided by RefSeq, Jul 2010]

Canonical amino-acid sequenceUniProt

631 residues, UniProt reviewed canonical sequence.

>P17405|SMPD1
     1  MPRYGASLRQ SCPRSGREQG QDGTAGAPGL LWMGLVLALA LALALALALS DSRVLWAPAE
    61  AHPLSPQGHP ARLHRIVPRL RDVFGWGNLT CPICKGLFTA INLGLKKEPN VARVGSVAIK
   121  LCNLLKIAPP AVCQSIVHLF EDDMVEVWRR SVLSPSEACG LLLGSTCGHW DIFSSWNISL
   181  PTVPKPPPKP PSPPAPGAPV SRILFLTDLH WDHDYLEGTD PDCADPLCCR RGSGLPPASR
   241  PGAGYWGEYS KCDLPLRTLE SLLSGLGPAG PFDMVYWTGD IPAHDVWHQT RQDQLRALTT
   301  VTALVRKFLG PVPVYPAVGN HESTPVNSFP PPFIEGNHSS RWLYEAMAKA WEPWLPAEAL
   361  RTLRIGGFYA LSPYPGLRLI SLNMNFCSRE NFWLLINSTD PAGQLQWLVG ELQAAEDRGD
   421  KVHIIGHIPP GHCLKSWSWN YYRIVARYEN TLAAQFFGHT HVDEFEVFYD EETLSRPLAV
   481  AFLAPSATTY IGLNPGYRVY QIDGNYSGSS HVVLDHETYI LNLTQANIPG AIPHWQLLYR
   541  ARETYGLPNT LPTAWHNLVY RMRGDMQLFQ TFWFLYHKGH PPSEPCGTPC RLATLCAQLS
   601  ARADSPALCR HLMPDGSLPE AQSLWPRPLF C

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against SMPD1 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)
0.27
Highest tissue expression
90 nTPM

Expression across tissuesHPA

Tissue

  • liver: 90 nTPM
  • kidney: 73 nTPM
  • heart muscle: 53 nTPM
  • pituitary gland: 41 nTPM
  • skin: 37 nTPM
  • skeletal muscle: 37 nTPM

Single-cell type

  • late spermatids: 366 nCPM
  • platelets: 133 nCPM
  • esophageal apical cells: 127 nCPM
  • hepatocytes: 84 nCPM
  • colonocytes: 79 nCPM
  • alveolar cells type 1: 70 nCPM

Immune cell

  • naive CD8 T-cell: 10 nTPM
  • naive CD4 T-cell: 10 nTPM
  • NK-cell: 6.6 nTPM
  • gdT-cell: 6.4 nTPM
  • memory CD4 T-cell: 5.5 nTPM
  • MAIT T-cell: 5 nTPM

Brain region

  • thalamus: 55 nTPM
  • white matter: 53 nTPM
  • cerebellum: 50 nTPM
  • basal ganglia: 48 nTPM
  • cerebral cortex: 47 nTPM
  • pons: 47 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about SMPD1.

Disease | AllUniProt

Conditions SMPD1 is implicated in, by any mechanism.

Disease | GeneticClinVar

384 pathogenic / likely-pathogenic of 1,199 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

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)
1.09
gnomAD pLI
0
gnomAD missense Z
-0.1
DepMap mean gene effect
0.04
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

InteractionsUniProt · HPA

Protein binding partners of SMPD1 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 SMPD1 as an antibody target. Whether an autoantibody or antibody against SMPD1 could matter depends on whether native SMPD1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

SMPD1 is annotated as secreted, so native SMPD1 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 SMPD1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/SMPD1. 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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