Seroatlas · Human Serome Atlas

SNRPA1

U2 small nuclear ribonucleoprotein A'

Also known as: Lea1, RU2A_HUMAN, U2A'

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

Protein identityUniProt · HPA

UniProt accession
P09661
Gene
SNRPA1
Ensembl
ENSG00000131876
Chromosome
15
Canonical length
255 aa
Protein class
Plasma proteins, Predicted intracellular proteins
Subcellular location
Nucleoplasm,Nuclear speckles,Nuclear bodies

OverviewNCBI Gene

Enables RNA binding activity. Involved in mRNA splicing, via spliceosome and spermatogenesis. Located in nuclear speck. Part of U2-type catalytic step 2 spliceosome and U2-type precatalytic spliceosome. Implicated in connective tissue disease. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

255 residues, UniProt reviewed canonical sequence.

>P09661|SNRPA1
     1  MVKLTAELIE QAAQYTNAVR DRELDLRGYK IPVIENLGAT LDQFDAIDFS DNEIRKLDGF
    61  PLLRRLKTLL VNNNRICRIG EGLDQALPCL TELILTNNSL VELGDLDPLA SLKSLTYLSI
   121  LRNPVTNKKH YRLYVIYKVP QVRVLDFQKV KLKERQEAEK MFKGKRGAQL AKDIARRSKT
   181  FNPGAGLPTD KKKGGPSPGD VEAIKNAIAN ASTLAEVERL KGLLQSGQIP GRERRSGPTD
   241  DGEEEMEEDT VTNGS

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against SNRPA1 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)
0.35
Highest tissue expression
64 nTPM

Expression across tissuesHPA

Tissue

  • bone marrow: 64 nTPM
  • tonsil: 49 nTPM
  • choroid plexus: 39 nTPM
  • lymph node: 39 nTPM
  • testis: 36 nTPM
  • thymus: 35 nTPM

Single-cell type

  • late primary spermatocytes: 323 nCPM
  • migrating cytotrophoblasts: 174 nCPM
  • extravillous trophoblasts: 165 nCPM
  • esophageal basal cells: 147 nCPM
  • cytotrophoblasts: 137 nCPM
  • gastric progenitor cells: 123 nCPM

Immune cell

  • T-reg: 58 nTPM
  • naive CD8 T-cell: 52 nTPM
  • myeloid DC: 52 nTPM
  • memory CD4 T-cell: 51 nTPM
  • MAIT T-cell: 50 nTPM
  • memory CD8 T-cell: 49 nTPM

Brain region

  • choroid plexus: 21 nTPM
  • cerebellum: 18 nTPM
  • thalamus: 17 nTPM
  • white matter: 17 nTPM
  • cerebral cortex: 16 nTPM
  • hippocampal formation: 16 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)
0.22
gnomAD pLI
0.99
gnomAD missense Z
1.87
DepMap mean gene effect
-2.82
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 SNRPA1 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 SNRPA1 as an antibody target. Whether an autoantibody or antibody against SNRPA1 could matter depends on whether native SNRPA1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

SNRPA1 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 SNRPA1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/SNRPA1. 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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