Seroatlas · Human Serome Atlas

IGHM

Immunoglobulin heavy constant mu

Also known as: IGHM_HUMAN

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

Protein identityUniProt · HPA

UniProt accession: P01871
Gene: IGHM
Ensembl: ENSG00000211899
Chromosome: 14
Canonical length: 474 aa
Protein class: Disease related genes, Immunoglobulin genes, Plasma proteins, Predicted intracellular proteins, Predicted membrane proteins, Predicted secreted proteins
Secretome location: Immunoglobulin genes
Quaternary structure: Homohexamer

OverviewNCBI Gene

Immunoglobulins (Ig) are the antigen recognition molecules of B cells. An Ig molecule is made up of 2 identical heavy chains and 2 identical light chains (see MIM 147200) joined by disulfide bonds so that each heavy chain is linked to a light chain and the 2 heavy chains are linked together. Each Ig heavy chain has an N-terminal variable (V) region containing the antigen-binding site and a C-terminal constant (C) region, encoded by an individual C region gene, that determines the isotype of the antibody and provides effector or signaling functions. The heavy chain V region is encoded by 1 each of 3 types of genes: V genes (see MIM 147070), joining (J) genes (see MIM 147010), and diversity (D) genes (see MIM 146910). The C region genes are clustered downstream of the V region genes within the heavy chain locus on chromosome 14. The IGHM gene encodes the C region of the mu heavy chain, which defines the IgM isotype. Naive B cells express the transmembrane forms of IgM and IgD (see IGHD; MIM 1471770) on their surface. During an antibody response, activated B cells can switch to the expression of individual downstream heavy chain C region genes by a process of somatic recombination known as isotype switching. In addition, secreted Ig forms that act as antibodies can be produced by alternative RNA processing of the heavy chain C region sequences. Although the membrane forms of all Ig isotypes are monomeric, secreted IgM forms pentamers, and occasionally hexamers, in plasma (summary by Janeway et al., 2005).[supplied by OMIM, Aug 2010]

Canonical amino-acid sequenceUniProt

474 residues, UniProt reviewed canonical sequence.

>P01871|IGHM
     1  GSASAPTLFP LVSCENSPSD TSSVAVGCLA QDFLPDSITF SWKYKNNSDI SSTRGFPSVL
    61  RGGKYAATSQ VLLPSKDVMQ GTDEHVVCKV QHPNGNKEKN VPLPVIAELP PKVSVFVPPR
   121  DGFFGNPRKS KLICQATGFS PRQIQVSWLR EGKQVGSGVT TDQVQAEAKE SGPTTYKVTS
   181  TLTIKESDWL GQSMFTCRVD HRGLTFQQNA SSMCVPDQDT AIRVFAIPPS FASIFLTKST
   241  KLTCLVTDLT TYDSVTISWT RQNGEAVKTH TNISESHPNA TFSAVGEASI CEDDWNSGER
   301  FTCTVTHTDL PSPLKQTISR PKGVALHRPD VYLLPPAREQ LNLRESATIT CLVTGFSPAD
   361  VFVQWMQRGQ PLSPEKYVTS APMPEPQAPG RYFAHSILTV SEEEWNTGET YTCVVAHEAL
   421  PNRVTERTVD KSTEGEVSAD EEGFENLWAT ASTFIVLFLL SLFYSTTVTL FKVK

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against IGHM 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: Cell surface
Secreted: No
Transmembrane segments: 0
Highest tissue expression: 3,965 nTPM

Expression across tissuesHPA

Tissue

spleen: 3,965 nTPM
lymph node: 2,995 nTPM
small intestine: 1,239 nTPM
duodenum: 1,133 nTPM
stomach: 499 nTPM
tonsil: 466 nTPM

Single-cell type

plasma cells: 486 nCPM
b-cells: 476 nCPM
pdcs: 59 nCPM
thymocytes: 31 nCPM
foveolar cells: 15 nCPM
gastric chief cells: 14 nCPM

Immune cell

naive B-cell: 6,750 nTPM
memory B-cell: 4,294 nTPM
total PBMC: 814 nTPM
plasmacytoid DC: 347 nTPM
neutrophil: 26 nTPM
NK-cell: 12 nTPM

Brain region

choroid plexus: 3.5 nTPM
cerebral cortex: 3.1 nTPM
medulla oblongata: 3 nTPM
spinal cord: 1.7 nTPM
pons: 1.1 nTPM
thalamus: 1.1 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about IGHM.

Disease | AllUniProt

Conditions IGHM is implicated in, by any mechanism.

Agammaglobulinemia 1, autosomal recessive (AGM1) MIM:601495

Disease | GeneticClinVar

6 pathogenic / likely-pathogenic of 10 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

Autosomal recessive agammaglobulinemia 1

Disease | ImmuneIEDB

Conditions an epitope on IGHM was assayed in.

rheumatoid arthritis B cell

OntologyGO

Biological processes

Molecular functions

antigen binding

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

InteractionsUniProt · HPA

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

IGHM is annotated at the cell surface, where native IGHM is exposed to circulating antibodies and is a prime autoantibody target that could block, deplete, or overstimulate it.

Source-annotated serology context

The source annotations explicitly mention antibody, autoantibody, autoantigen, or autoimmune context. This is biological context, not study-specific reactivity.

Each Ig heavy chain has an N-terminal variable (V) region containing the antigen-binding site and a C-terminal constant (C) region, encoded by an individual C region gene, that determines the isotype of the antibody and provides effector or signaling functions.
During an antibody response, activated B cells can switch to the expression of individual downstream heavy chain C region genes by a process of somatic recombination known as isotype switching.
In addition, secreted Ig forms that act as antibodies can be produced by alternative RNA processing of the heavy chain C region sequences.

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