Ig mu chain C region


Ig mu chain C region
Not Available
Gene Name
Amino acid sequence
>lcl|BSEQ0008862|Ig mu chain C region
Number of residues
Molecular Weight
Theoretical pI
Not Available
GO Classification
antigen binding
adaptive immune response / antibacterial humoral response / B cell receptor signaling pathway / complement activation, classical pathway / defense response to Gram-negative bacterium / Fc-epsilon receptor signaling pathway / Fc-gamma receptor signaling pathway involved in phagocytosis / innate immune response / phagocytosis, engulfment / phagocytosis, recognition / positive regulation of B cell activation / receptor-mediated endocytosis
blood microparticle / cell surface / external side of plasma membrane / extracellular exosome / extracellular space / hexameric IgM immunoglobulin complex / integral component of membrane / pentameric IgM immunoglobulin complex / plasma membrane
General Function
Antigen binding
Specific Function
IgM antibodies play an important role in primary defense mechanisms. They have been shown to be involved in early recognition of external invaders like bacteria and viruses, cellular waste and modified self, as well as in recognition and elimination of precancerous and cancerous lesions. The membrane-bound form is found in the majority of normal B-cells alongside with IgD. Membrane-bound IgM induces the phosphorylation of CD79A and CD79B by the Src family of protein tyrosine kinases. It may cause death of cells by apoptosis. It is also found in soluble form, which represents about 30% of the total serum immunoglobulins where it is found almost exclusively as a homopentamer. After the antigen binds to the B-cell receptor, the secreted form is secreted in large amounts.
Pfam Domain Function
Transmembrane Regions
Not Available
Cellular Location
Chromosome Location
Not Available
Not Available
External Identifiers
UniProtKB IDP01871
UniProtKB Entry NameIGHM_HUMAN
General References
  1. Dorai H, Gillies SD: The complete nucleotide sequence of a human immunoglobulin genomic C mu gene. Nucleic Acids Res. 1989 Aug 11;17(15):6412. [Article]
  2. Friedlander RM, Nussenzweig MC, Leder P: Complete nucleotide sequence of the membrane form of the human IgM heavy chain. Nucleic Acids Res. 1990 Jul 25;18(14):4278. [Article]
  3. Watanabe S, Barnikol HU, Horn J, Bertram J, Hilschmann N: [The primary structure of a monoclonal IgM-immunoglobulin (macroglobulin Gal.), II: the amino acid sequence of the H-chain (mu-type), subgroup H III. Architecture of the complete IgM-molecule (author's transl)]. Hoppe Seylers Z Physiol Chem. 1973 Oct-Nov;354(10-11):1505-9. [Article]
  4. Mihaesco E, Barnikol-Watanabe S, Barnikol HU, Mihaesco C, Hilschmann N: The primary structure of the constant part of mu-chain-disease protein BOT. Eur J Biochem. 1980 Oct;111(1):275-86. [Article]
  5. Putnam FW, Florent G, Paul C, Shinoda T, Shimizu A: Complete amino acid sequence of the Mu heavy chain of a human IgM immunoglobulin. Science. 1973 Oct 19;182(4109):287-91. [Article]
  6. Dolby TW, Devuono J, Croce CM: Cloning and partial nucleotide sequence of human immunoglobulin mu chain cDNA from B cells and mouse-human hybridomas. Proc Natl Acad Sci U S A. 1980 Oct;77(10):6027-31. [Article]
  7. Rabbitts TH, Forster A, Milstein CP: Human immunoglobulin heavy chain genes: evolutionary comparisons of C mu, C delta and C gamma genes and associated switch sequences. Nucleic Acids Res. 1981 Sep 25;9(18):4509-24. [Article]
  8. Tisch R, Roifman CM, Hozumi N: Functional differences between immunoglobulins M and D expressed on the surface of an immature B-cell line. Proc Natl Acad Sci U S A. 1988 Sep;85(18):6914-8. [Article]
  9. Yel L, Minegishi Y, Coustan-Smith E, Buckley RH, Trubel H, Pachman LM, Kitchingman GR, Campana D, Rohrer J, Conley ME: Mutations in the mu heavy-chain gene in patients with agammaglobulinemia. N Engl J Med. 1996 Nov 14;335(20):1486-93. [Article]
  10. Geisberger R, Lamers M, Achatz G: The riddle of the dual expression of IgM and IgD. Immunology. 2006 Aug;118(4):429-37. [Article]
  11. Bunkenborg J, Pilch BJ, Podtelejnikov AV, Wisniewski JR: Screening for N-glycosylated proteins by liquid chromatography mass spectrometry. Proteomics. 2004 Feb;4(2):454-65. [Article]
  12. Chen R, Jiang X, Sun D, Han G, Wang F, Ye M, Wang L, Zou H: Glycoproteomics analysis of human liver tissue by combination of multiple enzyme digestion and hydrazide chemistry. J Proteome Res. 2009 Feb;8(2):651-61. doi: 10.1021/pr8008012. [Article]
  13. Jia W, Lu Z, Fu Y, Wang HP, Wang LH, Chi H, Yuan ZF, Zheng ZB, Song LN, Han HH, Liang YM, Wang JL, Cai Y, Zhang YK, Deng YL, Ying WT, He SM, Qian XH: A strategy for precise and large scale identification of core fucosylated glycoproteins. Mol Cell Proteomics. 2009 May;8(5):913-23. doi: 10.1074/mcp.M800504-MCP200. Epub 2009 Jan 12. [Article]
  14. Burkard TR, Planyavsky M, Kaupe I, Breitwieser FP, Burckstummer T, Bennett KL, Superti-Furga G, Colinge J: Initial characterization of the human central proteome. BMC Syst Biol. 2011 Jan 26;5:17. doi: 10.1186/1752-0509-5-17. [Article]
  15. Bian Y, Song C, Cheng K, Dong M, Wang F, Huang J, Sun D, Wang L, Ye M, Zou H: An enzyme assisted RP-RPLC approach for in-depth analysis of human liver phosphoproteome. J Proteomics. 2014 Jan 16;96:253-62. doi: 10.1016/j.jprot.2013.11.014. Epub 2013 Nov 22. [Article]

Drug Relations

Drug Relations
DrugBank IDNameDrug groupPharmacological action?ActionsDetails
DB01593Zincapproved, investigationalunknownDetails
DB14487Zinc acetateapproved, investigationalunknownDetails