Seroatlas · Human Serome Atlas

CNN1

Calponin-1

Also known as: CNN1_HUMAN, Sm-Calp, SMCC

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

Protein identityUniProt · HPA

UniProt accession: P51911
Gene: CNN1
Ensembl: ENSG00000130176
Chromosome: 19
Canonical length: 297 aa
Protein class: Cancer-related genes, Predicted intracellular proteins
Subcellular location: Actin filaments

OverviewNCBI Gene

Predicted to enable actin filament binding activity. Involved in negative regulation of vascular associated smooth muscle cell proliferation. Located in cytoskeleton. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

297 residues, UniProt reviewed canonical sequence.

>P51911|CNN1
     1  MSSAHFNRGP AYGLSAEVKN KLAQKYDHQR EQELREWIEG VTGRRIGNNF MDGLKDGIIL
    61  CEFINKLQPG SVKKINESTQ NWHQLENIGN FIKAITKYGV KPHDIFEAND LFENTNHTQV
   121  QSTLLALASM AKTKGNKVNV GVKYAEKQER KFEPGKLREG RNIIGLQMGT NKFASQQGMT
   181  AYGTRRHLYD PKLGTDQPLD QATISLQMGT NKGASQAGMT APGTKRQIFE PGLGMEHCDT
   241  LNVSLQMGSN KGASQRGMTV YGLPRQVYDP KYCLTPEYPE LGEPAHNHHA HNYYNSA

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against CNN1 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): 0.48
Highest tissue expression: 2,743 nTPM

Expression across tissuesHPA

Tissue

colon: 2,743 nTPM
blood vessel: 2,087 nTPM
smooth muscle: 2,059 nTPM
endometrium: 1,691 nTPM
urinary bladder: 1,626 nTPM
seminal vesicle: 1,493 nTPM

Single-cell type

smooth muscle cells: 2,791 nCPM
breast myoepithelial cells: 837 nCPM
late spermatids: 741 nCPM
vascular smooth muscle cells: 526 nCPM
decidual stromal cells: 451 nCPM
early spermatids: 450 nCPM

Immune cell

total PBMC: 1.4 nTPM
myeloid DC: 0.1 nTPM
basophil: 0 nTPM
classical monocyte: 0 nTPM
eosinophil: 0 nTPM
gdT-cell: 0 nTPM

Brain region

cerebral cortex: 9.8 nTPM
hypothalamus: 7 nTPM
basal ganglia: 6.6 nTPM
choroid plexus: 4.8 nTPM
midbrain: 3.5 nTPM
hippocampal formation: 3 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): 0.64
gnomAD pLI: 0.14
gnomAD missense Z: 1.21
DepMap mean gene effect: 0.04
DepMap dependency class: selective

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

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads CNN1 as an antibody target. Whether an autoantibody or antibody against CNN1 could matter depends on whether native CNN1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

CNN1 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 CNN1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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