Seroatlas · Human Serome Atlas

MZB1

Marginal zone B- and B1-cell-specific protein

Also known as: HSPC190, MEDA-7, MGC29506, MZB1_HUMAN, PACAP, pERp1

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

Protein identityUniProt · HPA

UniProt accession: Q8WU39
Gene: MZB1
Ensembl: ENSG00000170476
Chromosome: 5
Canonical length: 189 aa
Protein class: Predicted secreted proteins
Subcellular location: Golgi apparatus
Secretome location: Secreted to blood

OverviewNCBI Gene

Involved in positive regulation of cell population proliferation. Located in cytoplasm and extracellular region. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

189 residues, UniProt reviewed canonical sequence.

>Q8WU39|MZB1
     1  MRLSLPLLLL LLGAWAIPGG LGDRAPLTAT APQLDDEEMY SAHMPAHLRC DACRAVAYQM
    61  WQNLAKAETK LHTSNSGGRR ELSELVYTDV LDRSCSRNWQ DYGVREVDQV KRLTGPGLSE
   121  GPEPSISVMV TGGPWPTRLS RTCLHYLGEF GEDQIYEAHQ QGRGALEALL CGGPQGACSE
   181  KVSATREEL

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against MZB1 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): 0.4
Highest tissue expression: 215 nTPM

Expression across tissuesHPA

Tissue

spleen: 215 nTPM
thymus: 137 nTPM
lymph node: 116 nTPM
tonsil: 110 nTPM
duodenum: 85 nTPM
appendix: 82 nTPM

Single-cell type

plasma cells: 4,017 nCPM
pdcs: 466 nCPM
gastric chief cells: 159 nCPM
thymocytes: 154 nCPM
foveolar cells: 94 nCPM
parietal cells: 69 nCPM

Immune cell

plasmacytoid DC: 571 nTPM
memory B-cell: 161 nTPM
naive B-cell: 76 nTPM
total PBMC: 26 nTPM
neutrophil: 3.1 nTPM
MAIT T-cell: 3 nTPM

Brain region

cerebral cortex: 1 nTPM
spinal cord: 0.7 nTPM
white matter: 0.5 nTPM
choroid plexus: 0.4 nTPM
thalamus: 0.2 nTPM
basal ganglia: 0.1 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): 1.49
gnomAD pLI: 0
gnomAD missense Z: 0.41
DepMap mean gene effect: 0.01
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

Cellular components

Protein domainsUniProt · Pfam · InterPro

Domain of unknown function DUF3456
TLR4 regulator and MIR-interacting MSAP
Marginal zone B- and B1-cell-specific protein

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of MZB1 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 MZB1 as an antibody target. Whether an autoantibody or antibody against MZB1 could matter depends on whether native MZB1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

MZB1 is annotated as secreted, so native MZB1 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 MZB1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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