Seroatlas · Human Serome Atlas

MSRB1

Methionine-R-sulfoxide reductase B1

Also known as: MSRB1_HUMAN, SELENOR, SELENOX, SelR, SelX, SepR, SEPX1

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

Protein identityUniProt · HPA

UniProt accession: Q9NZV6
Gene: MSRB1
Ensembl: ENSG00000198736
Chromosome: 16
Canonical length: 116 aa
Protein class: Enzymes, Predicted intracellular proteins
Subcellular location: Nucleoplasm

OverviewNCBI Gene

The protein encoded by this gene belongs to the methionine-R-sulfoxide reductase B (MsrB) family. Members of this family function as repair enzymes that protect proteins from oxidative stress by catalyzing the reduction of methionine-R-sulfoxides to methionines. This protein is highly expressed in liver and kidney, and is localized to the nucleus and cytosol. It is the only member of the MsrB family that is a selenoprotein, containing a selenocysteine (Sec) residue at its active site. It also has the highest methionine-R-sulfoxide reductase activity compared to other members containing cysteine in place of Sec. Sec is encoded by the UGA codon, which normally signals translation termination. The 3' UTRs of selenoprotein mRNAs contain a conserved stem-loop structure, designated the Sec insertion sequence (SECIS) element, that is necessary for the recognition of UGA as a Sec codon, rather than as a stop signal. A pseudogene of this locus has been identified on chromosome 19. [provided by RefSeq, Aug 2017]

Canonical amino-acid sequenceUniProt

116 residues, UniProt reviewed canonical sequence.

>Q9NZV6|MSRB1
     1  MSFCSFFGGE VFQNHFEPGV YVCAKCGYEL FSSRSKYAHS SPWPAFTETI HADSVAKRPE
    61  HNRSEALKVS CGKCGNGLGH EFLNDGPKPG QSRFUIFSSS LKFVPKGKET SASQGH

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against MSRB1 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
Highest tissue expression: 255 nTPM

Expression across tissuesHPA

Tissue

liver: 255 nTPM
pancreas: 152 nTPM
bone marrow: 92 nTPM
tongue: 88 nTPM
kidney: 87 nTPM
skeletal muscle: 80 nTPM

Single-cell type

neutrophils: 493 nCPM
hepatocytes: 290 nCPM
esophageal apical cells: 255 nCPM
neutrophil progenitors: 228 nCPM
epididymal efferent duct absorptive cells: 201 nCPM
extravillous trophoblasts: 157 nCPM

Immune cell

neutrophil: 3,078 nTPM
eosinophil: 1,424 nTPM
basophil: 497 nTPM
classical monocyte: 415 nTPM
total PBMC: 228 nTPM
intermediate monocyte: 196 nTPM

Brain region

medulla oblongata: 23 nTPM
thalamus: 21 nTPM
midbrain: 20 nTPM
cerebellum: 19 nTPM
spinal cord: 19 nTPM
basal ganglia: 18 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): 1.13
gnomAD pLI: 0.13
gnomAD missense Z: -0.12
DepMap mean gene effect: -0.09
DepMap dependency class: selective

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

Peptide methionine sulphoxide reductase MrsB domain
Mss4-like superfamily
SelR domain
Methionine-R-sulfoxide reductase B1

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads MSRB1 as an antibody target. Whether an autoantibody or antibody against MSRB1 could matter depends on whether native MSRB1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

MSRB1 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 MSRB1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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