SMR3B
Submaxillary gland androgen-regulated protein 3B
Also known as: P-B, PRL3, PROL3, SMR3B_HUMAN
Cross-references: UniProt · Ensembl · Human Protein Atlas · GeneCards · NCBI Gene
Protein identityUniProt · HPA
- UniProt accession
- P02814
- Gene
- SMR3B
- Ensembl
- ENSG00000171201
- Chromosome
- 4
- Canonical length
- 79 aa
- Protein class
- Predicted secreted proteins
- Secretome location
- Secreted to digestive system
OverviewNCBI Gene
Predicted to enable endopeptidase inhibitor activity. Predicted to be involved in cellular response to lipopolysaccharide; negative regulation of peptidase activity; and regulation of sensory perception of pain. Located in extracellular exosome. [provided by Alliance of Genome Resources, Jul 2025]
Canonical amino-acid sequenceUniProt
79 residues, UniProt reviewed canonical sequence.
>P02814|SMR3B
1 MKSLTWILGL WALAACFTPG ESQRGPRGPY PPGPLAPPQP FGPGFVPPPP PPPYGPGRIP
61 PPPPAPYGPG IFPPPPPQPLocalizationUniProt · AlphaFold · HPA
Whether an antibody against SMR3B 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
- Secreted
- Secreted
- Yes
- Transmembrane segments
- 0
- Mean surface accessibility (rSASA)
- 0.65
- Highest tissue expression
- 204,297 nTPM
Expression across tissuesHPA
Tissue
- salivary gland: 204,297 nTPM
- pancreas: 216 nTPM
- heart muscle: 42 nTPM
- placenta: 22 nTPM
- ovary: 19 nTPM
- adrenal gland: 8.5 nTPM
Single-cell type
- salivary acinar cells: 51,729 nCPM
- salivary myoepithelial cells: 8,408 nCPM
- lacrimal acinar cells: 1,169 nCPM
- neutrophils: 677 nCPM
- salivary basal cells: 448 nCPM
- nk-cells: 103 nCPM
Immune cell
- basophil: 0 nTPM
- classical monocyte: 0 nTPM
- eosinophil: 0 nTPM
- gdT-cell: 0 nTPM
- intermediate monocyte: 0 nTPM
- MAIT T-cell: 0 nTPM
Brain region
- midbrain: 1.6 nTPM
- thalamus: 0.7 nTPM
- cerebral cortex: 0.5 nTPM
- hypothalamus: 0.2 nTPM
- choroid plexus: 0.1 nTPM
- amygdala: 0 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)
- 1.74
- gnomAD pLI
- 0.39
- gnomAD missense Z
- -0.88
- DepMap mean gene effect
- -0.37
- DepMap dependency class
- selective
Cancer expressionTCGA
Across TCGA tumor cohorts, this protein is over-expressed in roughly 1% 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 SMR3B as an antibody target. Whether an autoantibody or antibody against SMR3B could matter depends on whether native SMR3B is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.
SMR3B is annotated as secreted, so native SMR3B circulates and is directly accessible to antibodies. Secreted and cell-surface proteins are the autoantibody targets most likely to act like drugs, blocking or depleting the native protein.
Annotation status
The present source text does not explicitly label SMR3B as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.
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