Seroatlas · Human Serome Atlas

SNU13

NHP2-like protein 1

Also known as: 15.5K, FA-1, NH2L1_HUMAN, NHP2L1, SNRNP15-5, SPAG12, SSFA1

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

Protein identityUniProt · HPA

UniProt accession
P55769
Gene
SNU13
Ensembl
ENSG00000100138
Chromosome
22
Canonical length
128 aa
Protein class
Predicted intracellular proteins, Ribosomal proteins

OverviewNCBI Gene

Originally named because of its sequence similarity to the Saccharomyces cerevisiae NHP2 (non-histone protein 2), this protein appears to be a highly conserved nuclear protein that is a component of the [U4/U6.U5] tri-snRNP. It binds to the 5' stem-loop of U4 snRNA. Two transcript variants encoding the same protein have been found for this gene. [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

128 residues, UniProt reviewed canonical sequence.

>P55769|SNU13
     1  MTEADVNPKA YPLADAHLTK KLLDLVQQSC NYKQLRKGAN EATKTLNRGI SEFIVMAADA
    61  EPLEIILHLP LLCEDKNVPY VFVRSKQALG RACGVSRPVI ACSVTIKEGS QLKQQIQSIQ
   121  QSIERLLV

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against SNU13 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)
0.29
Highest tissue expression
211 nTPM

Expression across tissuesHPA

Tissue

  • skeletal muscle: 211 nTPM
  • hypothalamus: 203 nTPM
  • cerebral cortex: 193 nTPM
  • heart muscle: 167 nTPM
  • tongue: 166 nTPM
  • cerebellum: 164 nTPM

Single-cell type

  • late primary spermatocytes: 1,304 nCPM
  • early spermatids: 1,157 nCPM
  • gastric progenitor cells: 637 nCPM
  • oocytes: 580 nCPM
  • esophageal basal cells: 571 nCPM
  • esophageal suprabasal cells: 564 nCPM

Immune cell

  • memory B-cell: 359 nTPM
  • T-reg: 347 nTPM
  • total PBMC: 341 nTPM
  • naive B-cell: 313 nTPM
  • plasmacytoid DC: 289 nTPM
  • naive CD4 T-cell: 267 nTPM

Brain region

  • hypothalamus: 216 nTPM
  • pons: 181 nTPM
  • midbrain: 150 nTPM
  • medulla oblongata: 146 nTPM
  • cerebral cortex: 145 nTPM
  • basal ganglia: 142 nTPM

ReferencesPubMed · IEDB

Publications for SNU13 from three distinct lines of evidence, kept separate because they answer different questions: whether antibodies are directed at the protein, whether a B-cell epitope has been mapped on it, and whether a T-cell epitope has. Each is labelled with its source.

Reference: AutoantibodyPubMed

2 publications

Sources: PubMed — antigen-level antibody evidence from a custom retrieval. Records matching a controlled set of autoantibody terms (the MeSH descriptors Autoantibodies and Autoantigens, with title and abstract term variants) were obtained through NCBI E-utilities, and their titles and abstracts parsed for constructions that direct an antibody at a named protein rather than for co-occurrence. Captured names were resolved against UniProt nomenclature and each antigen adjudicated individually against the source text. Bibliographic records from PubMed and MeSH, U.S. National Library of Medicine; citation metrics from NIH iCite (Hutchins et al., PLoS Biology 2016). Titles link to PubMed; abstracts are not reproduced here. The NLM does not endorse this analysis.

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)
0.66
gnomAD pLI
0.75
DepMap mean gene effect
-2.41
DepMap dependency class
pan

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 6% 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 SNU13 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 SNU13 as an antibody target. Whether an autoantibody or antibody against SNU13 could matter depends on whether native SNU13 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

SNU13 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 SNU13 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/SNU13. 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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