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ENDOU endonuclease, poly(U) specific [ Homo sapiens (human) ]

Gene ID: 8909, updated on 19-May-2026
Official Symbol
ENDOUprovided by HGNC
Official Full Name
endonuclease, poly(U) specificprovided by HGNC
Primary source
HGNC:HGNC:14369
See related
Ensembl:ENSG00000111405 MIM:606720; AllianceGenome:HGNC:14369
Gene type
protein coding
RefSeq status
REVIEWED
Organism
Homo sapiens
Lineage
Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae; Homo
Also known as
P11; PP11; PRSS26
Summary
This gene encodes a protein with endoribonuclease activity that binds polyuridine-enriched single-stranded RNA. This gene was initially characterized based on its high expression in placenta but was mischaracterized as a serine protease. In mouse, this gene promotes tolerance to self-antigens by regulating B cell activation-induced cell death (AICD). The protein may be useful as a tumor marker. Multiple alternatively spliced transcript variants encoding distinct protein isoforms have been found for this gene. [provided by RefSeq, Jul 2020]
Expression
Biased expression in esophagus (RPKM 34.0), skin (RPKM 9.4) and 1 other tissue See more
Orthologs
all
Try the new Gene page
Try the new Transcripts and proteins table
See ENDOU in Genome Data Viewer
Location:
12q13.11
Exon count:
10
Annotation release Status Assembly Chr Location
RS_2025_08 current GRCh38.p14 (GCF_000001405.40) 12 NC_000012.12 (47709734..47725490, complement)
RS_2025_08 current T2T-CHM13v2.0 (GCF_009914755.1) 12 NC_060936.1 (47671053..47686808, complement)
RS_2024_09 previous assembly GRCh37.p13 (GCF_000001405.25) 12 NC_000012.11 (48103517..48119273, complement)

Chromosome 12 - NC_000012.12Genomic Context describing neighboring genes Neighboring gene STBD1 pseudogene 1 Neighboring gene H3K27ac-H3K4me1 hESC enhancer GRCh37_chr12:48030175-48030714 Neighboring gene ATAC-STARR-seq lymphoblastoid active region 6256 Neighboring gene RNA polymerase II associated protein 3 Neighboring gene H3K27ac hESC enhancers GRCh37_chr12:48099027-48099528 and GRCh37_chr12:48099529-48100028 Neighboring gene ATAC-STARR-seq lymphoblastoid active region 6258 Neighboring gene ATAC-STARR-seq lymphoblastoid active region 6259 Neighboring gene RPAP3 divergent transcript Neighboring gene ATAC-STARR-seq lymphoblastoid silent region 4394 Neighboring gene ATAC-STARR-seq lymphoblastoid silent region 4395 Neighboring gene BRD4-independent group 4 enhancer GRCh37_chr12:48131928-48133127 Neighboring gene ATAC-STARR-seq lymphoblastoid active region 6260 Neighboring gene ATAC-STARR-seq lymphoblastoid active region 6261 Neighboring gene H3K27ac hESC enhancer GRCh37_chr12:48146243-48146784 Neighboring gene Sharpr-MPRA regulatory region 8178 Neighboring gene ATAC-STARR-seq lymphoblastoid active region 6262 Neighboring gene ATAC-STARR-seq lymphoblastoid active region 6263 Neighboring gene Rap guanine nucleotide exchange factor 3 Neighboring gene H3K27ac-H3K4me1 hESC enhancer GRCh37_chr12:48151874-48152542 Neighboring gene H3K4me1 hESC enhancer GRCh37_chr12:48152543-48153211 Neighboring gene H3K4me1 hESC enhancer GRCh37_chr12:48167242-48167748 Neighboring gene H3K4me1 hESC enhancer GRCh37_chr12:48167749-48168253 Neighboring gene solute carrier family 48 member 1 Neighboring gene ATAC-STARR-seq lymphoblastoid silent region 4398 Neighboring gene ATAC-STARR-seq lymphoblastoid silent region 4399 Neighboring gene uncharacterized LOC124902926 Neighboring gene histone deacetylase 7

Go to nucleotide: Graphics FASTA GenBank

  • Project title: Tissue-specific circular RNA induction during human fetal development
  • Description: 35 human fetal samples from 6 tissues (3 - 7 replicates per tissue) collected between 10 and 20 weeks gestational time were sequenced using Illumina TruSeq Stranded Total RNA
  • BioProject: PRJNA270632
  • Publication: PMID 26076956
  • Analysis date: Mon Apr 2 22:54:59 2018

Related articles in PubMed

  1. Homology of placental protein 11 and pea seed albumin 2 with vitronectin. Jenne D. Biochem Biophys Res Commun, 1991 May 15. PMID 1710108
  2. (1)H, (13)C and (15)N backbone resonance assignment of the calcium-activated EndoU endoribonuclease. Malard F, et al. Biomol NMR Assign, 2024 Dec. PMID 39249657, Free PMC Article
  3. The tumor marker human placental protein 11 is an endoribonuclease. Laneve P, et al. J Biol Chem, 2008 Dec 12. PMID 18936097, Free PMC Article
  4. Cloning and expression of a cDNA encoding human placental protein 11, a putative serine protease with diagnostic significance as a tumor marker. Grundmann U, et al. DNA Cell Biol, 1990 May. PMID 2350438
  5. Immunohistochemical detection of pregnancy-specific protein (SP1) and placenta-specific tissue proteins (PP5, PP10, PP11 and PP12) in ovarian adenocarcinomas. Inaba N, et al. Oncodev Biol Med, 1982. PMID 6755403

See all (17) citations in PubMed

GeneRIFs: Gene References Into Functions

What's a GeneRIF?
  1. [1]H, [13]C and [15]N backbone resonance assignment of the calcium-activated EndoU endoribonuclease.
    Title: (1)H, (13)C and (15)N backbone resonance assignment of the calcium-activated EndoU endoribonuclease.
  2. Poly(U)-specific endoribonuclease ENDOU promotes translation of human CHOP mRNA by releasing uORF element-mediated inhibition.
    Title: Poly(U)-specific endoribonuclease ENDOU promotes translation of human CHOP mRNA by releasing uORF element-mediated inhibition.
  3. Connecting the dots on vertical transmission of SARS-CoV-2 using protein-protein interaction network analysis - Potential roles of placental ACE2 and ENDOU.
    Title: Connecting the dots on vertical transmission of SARS-CoV-2 using protein-protein interaction network analysis - Potential roles of placental ACE2 and ENDOU.
  4. Clinical trial of gene-disease association and gene-environment interaction. (HuGE Navigator)
    Title: Personalized smoking cessation: interactions between nicotine dose, dependence and quit-success genotype score.
  5. human placental protein 11 is an endoribonuclease
    Title: The tumor marker human placental protein 11 is an endoribonuclease.
Submit: New GeneRIF Correction

Find tests for this gene in the NIH Genetic Testing Registry (GTR)

Review eQTL and phenotype association data in this region using PheGenI

See variants in ClinVar

See studies and variants in dbVar

See Variation Viewer (GRCh37.p13)

Products Interactant Other Gene Complex Source Pubs Description

Markers

Homology

Clone Names

  • MGC133268

Gene Ontology Provided by GOA

Function Evidence Code Pubs
enables RNA binding IDA
Inferred from Direct Assay
more info
 PubMed 
enables RNA endonuclease activity IBA
Inferred from Biological aspect of Ancestor
more info
  
enables RNA endonuclease activity IDA
Inferred from Direct Assay
more info
 PubMed 
enables RNA endonuclease activity IEA
Inferred from Electronic Annotation
more info
  
enables RNA endonuclease activity IGI
Inferred from Genetic Interaction
more info
 PubMed 
enables RNA nuclease activity IEA
Inferred from Electronic Annotation
more info
  
enables growth factor activity NAS
Non-traceable Author Statement
more info
 PubMed 
enables manganese ion binding TAS
Traceable Author Statement
more info
 PubMed 
enables polysaccharide binding IEA
Inferred from Electronic Annotation
more info
  
enables scavenger receptor activity IEA
Inferred from Electronic Annotation
more info
  
NOT enables serine-type peptidase activity IDA
Inferred from Direct Assay
more info
 PubMed 
enables serine-type peptidase activity IDA
Inferred from Direct Assay
more info
 PubMed 
Process Evidence Code Pubs
involved_in female pregnancy IEP
Inferred from Expression Pattern
more info
 PubMed 
involved_in immune response IEA
Inferred from Electronic Annotation
more info
  
involved_in negative regulation of lipid catabolic process IGI
Inferred from Genetic Interaction
more info
 PubMed 
involved_in post-transcriptional gene silencing IGI
Inferred from Genetic Interaction
more info
 PubMed 
involved_in proteolysis IDA
Inferred from Direct Assay
more info
 PubMed 
involved_in signal transduction IEA
Inferred from Electronic Annotation
more info
  
involved_in vesicle-mediated transport IEA
Inferred from Electronic Annotation
more info
  
Component Evidence Code Pubs
located_in cytoplasm IDA
Inferred from Direct Assay
more info
 PubMed 
located_in cytoplasm TAS
Traceable Author Statement
more info
 PubMed 
located_in extracellular region IEA
Inferred from Electronic Annotation
more info
  
located_in extracellular region TAS
Traceable Author Statement
more info
 PubMed 
located_in plasma membrane TAS
Traceable Author Statement
more info
 PubMed 
Preferred Names
uridylate-specific endoribonuclease
Names
22 serine protease
26 serine protease
endonuclease, polyU-specific
placental protein 11
poly(U)-specific endoribonuclease
protein endoU

NEW Try the new Transcript table

RefSeqs maintained independently of Annotated Genomes

These reference sequences exist independently of genome builds. Explain

These reference sequences are curated independently of the genome annotation cycle, so their versions may not match the RefSeq versions in the current genome build. Identify version mismatches by comparing the version of the RefSeq in this section to the one reported in Genomic regions, transcripts, and products above.

mRNA and Protein(s)

  1. NM_001172439.2 → NP_001165910.1  uridylate-specific endoribonuclease isoform 1 precursor

    See identical proteins and their annotated locations for NP_001165910.1

    Status: REVIEWED

    Description
    Transcript Variant: This variant (1) represents the longest transcript and encodes the longest protein (isoform 1).
    Source sequence(s)
    AI039727, AK075446, BC069698
    Consensus CDS
    CCDS53785.1
    UniProtKB/Swiss-Prot
    B2RBJ3, B3KQS7, B7Z6E1, P21128, Q2NKJ4
    Related
    ENSP00000397679.3, ENST00000422538.8
    Conserved Domains (3) summary
    smart00201
    Location:86 → 128
    SO; Somatomedin B -like domains
    pfam01033
    Location:22 → 60
    Somatomedin_B; Somatomedin B domain
    pfam09412
    Location:139 → 405
    XendoU; Endoribonuclease XendoU

  2. NM_001172440.2 → NP_001165911.1  uridylate-specific endoribonuclease isoform 3 precursor

    See identical proteins and their annotated locations for NP_001165911.1

    Status: REVIEWED

    Description
    Transcript Variant: This variant (3) lacks two alternate in-frame exons, compared to variant 1. The resulting protein (isoform 3) has a shorter N-terminus, compared to isoform 1.
    Source sequence(s)
    AC004241, AI039727, AK300169, DC381238
    Consensus CDS
    CCDS53784.1
    UniProtKB/Swiss-Prot
    P21128
    Related
    ENSP00000445004.2, ENST00000545824.2
    Conserved Domains (2) summary
    smart00201
    Location:23 → 65
    SO; Somatomedin B -like domains
    pfam09412
    Location:76 → 342
    XendoU; Endoribonuclease XendoU

  3. NM_006025.4 → NP_006016.1  uridylate-specific endoribonuclease isoform 2 precursor

    See identical proteins and their annotated locations for NP_006016.1

    Status: REVIEWED

    Description
    Transcript Variant: This variant (2) lacks an alternate in-frame exon in the 5' coding region, compared to variant 1. The resulting protein (isoform 2) has a shorter N-terminus, compared to isoform 1.
    Source sequence(s)
    AC004241, AI039727, BC111782
    Consensus CDS
    CCDS8754.1
    UniProtKB/Swiss-Prot
    P21128
    Related
    ENSP00000229003.3, ENST00000229003.7
    Conserved Domains (2) summary
    smart00201
    Location:45 → 87
    SO; Somatomedin B -like domains
    pfam09412
    Location:98 → 364
    XendoU; Endoribonuclease XendoU

RefSeqs of Annotated Genomes: GCF_000001405.40-RS_2025_08

The following sections contain reference sequences that belong to a specific genome build. Explain

Reference GRCh38.p14 Primary Assembly

Genomic

  1. NC_000012.12 Reference GRCh38.p14 Primary Assembly

    Range
    47709734..47725490 complement
    Download
    GenBank, FASTA, Sequence Viewer (Graphics)

Alternate T2T-CHM13v2.0

Genomic

  1. NC_060936.1 Alternate T2T-CHM13v2.0

    Range
    47671053..47686808 complement
    Download
    GenBank, FASTA, Sequence Viewer (Graphics)
Nucleotide Protein
Heading Accession and Version
Protein Accession Links
GenPept Link UniProtKB Link
P21128.2 GenPept UniProtKB/Swiss-Prot:P21128

Gene LinkOut

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