Seroatlas · Human Serome Atlas

SPPL2C

Signal peptide peptidase-like 2C

Also known as: IMP5, SPP2C_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
Q8IUH8
Gene
SPPL2C
Ensembl
ENSG00000185294
Chromosome
17
Canonical length
684 aa
Protein class
Enzymes, Predicted membrane proteins

OverviewNCBI Gene

Enables protein homodimerization activity. Predicted to be involved in several processes, including acrosome assembly; fusion of sperm to egg plasma membrane involved in single fertilization; and membrane protein intracellular domain proteolysis. Located in cytoplasmic side of endoplasmic reticulum membrane and lumenal side of endoplasmic reticulum membrane. [provided by Alliance of Genome Resources, Apr 2025]

Canonical amino-acid sequenceUniProt

684 residues, UniProt reviewed canonical sequence.

>Q8IUH8|SPPL2C
     1  MACLGFLLPV GFLLLISTVA GGKYGVAHVV SENWSKDYCI LFSSDYITLP RDLHHAPLLP
    61  LYDGTKAPWC PGEDSPHQAQ LRSPSQRPLR QTTAMVMRGN CSFHTKGWLA QGQGAHGLLI
   121  VSRVSDQQCS DTTLAPQDPR QPLADLTIPV AMLHYADMLD ILSHTRGEAV VRVAMYAPPE
   181  PIIDYNMLVI FILAVGTVAA GGYWAGLTEA NRLQRRRARR GGGSGGHHQL QEAAAAEGAQ
   241  KEDNEDIPVD FTPAMTGVVV TLSCSLMLLL YFFYDHFVYV TIGIFGLGAG IGLYSCLSPL
   301  VCRLSLRQYQ RPPHSLWASL PLPLLLLASL CATVIIFWVA YRNEDRWAWL LQDTLGISYC
   361  LFVLHRVRLP TLKNCSSFLL ALLAFDVFFV FVTPFFTKTG ESIMAQVALG PAESSSHERL
   421  PMVLKVPRLR VSALTLCSQP FSILGFGDIV VPGFLVAYCC RFDVQVCSRQ IYFVACTVAY
   481  AVGLLVTFMA MVLMQMGQPA LLYLVSSTLL TSLAVAACRQ ELSLFWTGQG RAKMCGLGCA
   541  PSAGSRQKQE GAADAHTAST LERGTSRGAG DLDSNPGEDT TEIVTISENE ATNPEDRSDS
   601  SEGWSDAHLD PNELPFIPPG ASEELMPLMP MAMLIPLMPL MPPPSELGHV HAQAQAHETG
   661  LPWAGLHKRK GLKVRKSMST QAPL

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against SPPL2C 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
9
Mean surface accessibility (rSASA)
0.42
Highest tissue expression
36 nTPM

Expression across tissuesHPA

Tissue

  • testis: 36 nTPM
  • cerebellum: 1.7 nTPM
  • pituitary gland: 0.4 nTPM
  • cerebral cortex: 0.3 nTPM
  • amygdala: 0.2 nTPM
  • basal ganglia: 0.1 nTPM

Single-cell type

  • late spermatids: 0.2 nCPM
  • adipocytes: 0 nCPM
  • adrenal cortex cells: 0 nCPM
  • adrenal medulla cells: 0 nCPM
  • alveolar cells type 1: 0 nCPM
  • alveolar cells type 2: 0 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

  • amygdala: 0.7 nTPM
  • cerebral cortex: 0.7 nTPM
  • cerebellum: 0.5 nTPM
  • hippocampal formation: 0.4 nTPM
  • thalamus: 0.4 nTPM
  • white matter: 0.4 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)
1.03
gnomAD pLI
0
gnomAD missense Z
0.19
DepMap mean gene effect
-0.14
DepMap dependency class
selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 3% 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 SPPL2C 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 SPPL2C as an antibody target. Whether an autoantibody or antibody against SPPL2C could matter depends on whether native SPPL2C is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

SPPL2C 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 SPPL2C as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/SPPL2C. 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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