Seroatlas · Human Serome Atlas

APBA2

Amyloid-beta A4 precursor protein-binding family A member 2

Also known as: APBA2_HUMAN, D15S1518E, HsT16821, LIN-10, MGC:14091, MINT2, X11L

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

Protein identityUniProt · HPA

UniProt accession
Q99767
Gene
APBA2
Ensembl
ENSG00000034053
Chromosome
15
Canonical length
749 aa
Protein class
Predicted intracellular proteins, Transporters
Subcellular location
Golgi apparatus

OverviewNCBI Gene

The protein encoded by this gene is a member of the X11 protein family. It is a neuronal adapter protein that interacts with the Alzheimer's disease amyloid precursor protein (APP). It stabilizes APP and inhibits production of proteolytic APP fragments including the A beta peptide that is deposited in the brains of Alzheimer's disease patients. This gene product is believed to be involved in signal transduction processes. It is also regarded as a putative vesicular trafficking protein in the brain that can form a complex with the potential to couple synaptic vesicle exocytosis to neuronal cell adhesion. [provided by RefSeq, Jul 2017]

Canonical amino-acid sequenceUniProt

749 residues, UniProt reviewed canonical sequence.

>Q99767|APBA2
     1  MAHRKLESVG SGMLDHRVRP GPVPHSQEPE SEDMELPLEG YVPEGLELAA LRPESPAPEE
    61  QECHNHSPDG DSSSDYVNNT SEEEDYDEGL PEEEEGITYY IRYCPEDDSY LEGMDCNGEE
   121  YLAHSAHPVD TDECQEAVEE WTDSAGPHPH GHEAEGSQDY PDGQLPIPED EPSVLEAHDQ
   181  EEDGHYCASK EGYQDYYPEE ANGNTGASPY RLRRGDGDLE DQEEDIDQIV AEIKMSLSMT
   241  SITSASEASP EHGPEPGPED SVEACPPIKA SCSPSRHEAR PKSLNLLPEA KHPGDPQRGF
   301  KPKTRTPEER LKWPHEQVCN GLEQPRKQQR SDLNGPVDNN NIPETKKVAS FPSFVAVPGP
   361  CEPEDLIDGI IFAANYLGST QLLSERNPSK NIRMMQAQEA VSRVKRMQKA AKIKKKANSE
   421  GDAQTLTEVD LFISTQRIKV LNADTQETMM DHALRTISYI ADIGNIVVLM ARRRMPRSAS
   481  QDCIETTPGA QEGKKQYKMI CHVFESEDAQ LIAQSIGQAF SVAYQEFLRA NGINPEDLSQ
   541  KEYSDIINTQ EMYNDDLIHF SNSENCKELQ LEKHKGEILG VVVVESGWGS ILPTVILANM
   601  MNGGPAARSG KLSIGDQIMS INGTSLVGLP LATCQGIIKG LKNQTQVKLN IVSCPPVTTV
   661  LIKRPDLKYQ LGFSVQNGII CSLMRGGIAE RGGVRVGHRI IEINGQSVVA TAHEKIVQAL
   721  SNSVGEIHMK TMPAAMFRLL TGQETPLYI

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against APBA2 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
Cell surface
Secreted
No
Transmembrane segments
0
Mean surface accessibility (rSASA)
0.49
Highest tissue expression
77 nTPM

Expression across tissuesHPA

Tissue

  • cerebellum: 77 nTPM
  • cerebral cortex: 70 nTPM
  • hippocampal formation: 61 nTPM
  • spinal cord: 47 nTPM
  • amygdala: 44 nTPM
  • midbrain: 39 nTPM

Single-cell type

  • brain excitatory neurons: 183 nCPM
  • oligodendrocyte progenitor cells: 166 nCPM
  • bergmann glia: 164 nCPM
  • astrocytes: 146 nCPM
  • oligodendrocytes: 107 nCPM
  • brain inhibitory neurons: 105 nCPM

Immune cell

  • naive CD8 T-cell: 5 nTPM
  • naive CD4 T-cell: 4.5 nTPM
  • memory CD8 T-cell: 2.8 nTPM
  • total PBMC: 1.7 nTPM
  • memory CD4 T-cell: 1.4 nTPM
  • NK-cell: 1.1 nTPM

Brain region

  • cerebral cortex: 34 nTPM
  • hippocampal formation: 33 nTPM
  • cerebellum: 33 nTPM
  • white matter: 25 nTPM
  • basal ganglia: 24 nTPM
  • amygdala: 23 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)
0.38
gnomAD pLI
0.74
gnomAD missense Z
1.46
DepMap mean gene effect
-0.14
DepMap dependency class
selective

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 APBA2 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 APBA2 as an antibody target. Whether an autoantibody or antibody against APBA2 could matter depends on whether native APBA2 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

APBA2 is annotated at the cell surface, where native APBA2 is exposed to circulating antibodies and is a prime autoantibody target that could block, deplete, or overstimulate it.

Annotation status

The present source text does not explicitly label APBA2 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/APBA2. 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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