Seroatlas · Human Serome Atlas

PTTG1

Securin

Also known as: EAP1, ECRAR, HPTTG, PTTG, PTTG1_HUMAN, securin, TUTR1

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

Protein identityUniProt · HPA

UniProt accession
O95997
Gene
PTTG1
Ensembl
ENSG00000164611
Chromosome
5
Canonical length
202 aa
Protein class
Cancer-related genes, Predicted intracellular proteins
Subcellular location
Nucleoli,Cytosol

OverviewNCBI Gene

The encoded protein is a homolog of yeast securin proteins, which prevent separins from promoting sister chromatid separation. It is an anaphase-promoting complex (APC) substrate that associates with a separin until activation of the APC. The gene product has transforming activity in vitro and tumorigenic activity in vivo, and the gene is highly expressed in various tumors. The gene product contains 2 PXXP motifs, which are required for its transforming and tumorigenic activities, as well as for its stimulation of basic fibroblast growth factor expression. It also contains a destruction box (D box) that is required for its degradation by the APC. The acidic C-terminal region of the encoded protein can act as a transactivation domain. The gene product is mainly a cytosolic protein, although it partially localizes in the nucleus. Three transcript variants encoding the same protein have been found for this gene. [provided by RefSeq, Sep 2013]

Canonical amino-acid sequenceUniProt

202 residues, UniProt reviewed canonical sequence.

>O95997|PTTG1
     1  MATLIYVDKE NGEPGTRVVA KDGLKLGSGP SIKALDGRSQ VSTPRFGKTF DAPPALPKAT
    61  RKALGTVNRA TEKSVKTKGP LKQKQPSFSA KKMTEKTVKA KSSVPASDDA YPEIEKFFPF
   121  NPLDFESFDL PEEHQIAHLP LSGVPLMILD EERELEKLFQ LGPPSPVKMP SPPWESNLLQ
   181  SPSSILSTLD VELPPVCCDI DI

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against PTTG1 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)
0.69
Highest tissue expression
164 nTPM

Expression across tissuesHPA

Tissue

  • testis: 164 nTPM
  • bone marrow: 151 nTPM
  • tonsil: 135 nTPM
  • thymus: 118 nTPM
  • lymph node: 76 nTPM
  • thyroid gland: 74 nTPM

Single-cell type

  • late primary spermatocytes: 1,846 nCPM
  • early spermatids: 623 nCPM
  • esophageal basal cells: 520 nCPM
  • oocytes: 336 nCPM
  • gastric progenitor cells: 308 nCPM
  • basal keratinocytes: 253 nCPM

Immune cell

  • T-reg: 219 nTPM
  • memory CD8 T-cell: 61 nTPM
  • memory CD4 T-cell: 53 nTPM
  • naive CD8 T-cell: 32 nTPM
  • memory B-cell: 31 nTPM
  • gdT-cell: 26 nTPM

Brain region

  • hippocampal formation: 9.9 nTPM
  • cerebral cortex: 8.4 nTPM
  • hypothalamus: 7.2 nTPM
  • basal ganglia: 4.8 nTPM
  • thalamus: 4.6 nTPM
  • pons: 3.6 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)
1.41
gnomAD pLI
0
gnomAD missense Z
0.96
DepMap mean gene effect
-0.61
DepMap dependency class
common

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 PTTG1 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 PTTG1 as an antibody target. Whether an autoantibody or antibody against PTTG1 could matter depends on whether native PTTG1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

PTTG1 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 PTTG1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/PTTG1. 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...