Seroatlas · Human Serome Atlas

CASQ1

Calsequestrin-1

Also known as: CASQ, CASQ1_HUMAN, PDIB1

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

Protein identityUniProt · HPA

UniProt accession
P31415
Gene
CASQ1
Ensembl
ENSG00000143318
Chromosome
1
Canonical length
396 aa
Protein class
Disease related genes, Human disease related genes, Potential drug targets, Predicted intracellular proteins, Transporters
Subcellular location
Nucleoplasm,Mitochondria
Secretome location
Intracellular and membrane
Quaternary structure
Homotetramer

OverviewNCBI Gene

This gene encodes the skeletal muscle specific member of the calsequestrin protein family. Calsequestrin functions as a luminal sarcoplasmic reticulum calcium sensor in both cardiac and skeletal muscle cells. This protein, also known as calmitine, functions as a calcium regulator in the mitochondria of skeletal muscle. This protein is absent in patients with Duchenne and Becker types of muscular dystrophy. [provided by RefSeq, Jun 2013]

Canonical amino-acid sequenceUniProt

396 residues, UniProt reviewed canonical sequence.

>P31415|CASQ1
     1  MSATDRMGPR AVPGLRLALL LLLVLGTPKS GVQGQEGLDF PEYDGVDRVI NVNAKNYKNV
    61  FKKYEVLALL YHEPPEDDKA SQRQFEMEEL ILELAAQVLE DKGVGFGLVD SEKDAAVAKK
   121  LGLTEVDSMY VFKGDEVIEY DGEFSADTIV EFLLDVLEDP VELIEGEREL QAFENIEDEI
   181  KLIGYFKSKD SEHYKAFEDA AEEFHPYIPF FATFDSKVAK KLTLKLNEID FYEAFMEEPV
   241  TIPDKPNSEE EIVNFVEEHR RSTLRKLKPE SMYETWEDDM DGIHIVAFAE EADPDGFEFL
   301  ETLKAVAQDN TENPDLSIIW IDPDDFPLLV PYWEKTFDID LSAPQIGVVN VTDADSVWME
   361  MDDEEDLPSA EELEDWLEDV LEGEINTEDD DDDDDD

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against CASQ1 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
Other membrane
Secreted
No
Transmembrane segments
0
Mean surface accessibility (rSASA)
0.33
Highest tissue expression
4,162 nTPM

Expression across tissuesHPA

Tissue

  • skeletal muscle: 4,162 nTPM
  • tongue: 1,767 nTPM
  • retina: 46 nTPM
  • heart muscle: 42 nTPM
  • esophagus: 41 nTPM
  • salivary gland: 16 nTPM

Single-cell type

  • myonuclei: 182 nCPM
  • thymic myoid cells: 48 nCPM
  • rod photoreceptor cells: 28 nCPM
  • cone photoreceptor cells: 23 nCPM
  • syncytiotrophoblasts: 9.6 nCPM
  • retinal ganglion cells: 7.7 nCPM

Immune cell

  • neutrophil: 0.3 nTPM
  • basophil: 0.1 nTPM
  • classical monocyte: 0.1 nTPM
  • eosinophil: 0 nTPM
  • gdT-cell: 0 nTPM
  • intermediate monocyte: 0 nTPM

Brain region

  • cerebral cortex: 10 nTPM
  • hippocampal formation: 9.6 nTPM
  • white matter: 8.9 nTPM
  • basal ganglia: 8.4 nTPM
  • cerebellum: 6 nTPM
  • amygdala: 4.6 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about CASQ1.

Disease | AllUniProt

Conditions CASQ1 is implicated in, by any mechanism.

  • Myopathy, vacuolar, with CASQ1 aggregates (VMCQA) MIM:616231
  • Myopathy, tubular aggregate, 1 (TAM1) MIM:160565

Disease | GeneticClinVar

5 pathogenic / likely-pathogenic of 403 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

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)
1.58
gnomAD pLI
0
gnomAD missense Z
-0.02
DepMap mean gene effect
0.1
DepMap dependency class
none

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 3% 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 CASQ1 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 CASQ1 as an antibody target. Whether an autoantibody or antibody against CASQ1 could matter depends on whether native CASQ1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

CASQ1 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 CASQ1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/CASQ1. 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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