ID IGHM_HUMAN Reviewed; 474 AA. AC P01871; A0A075B6N9; A0A0G2JQL4; P04220; P20769; DT 21-JUL-1986, integrated into UniProtKB/Swiss-Prot. DT 03-MAY-2023, sequence version 5. DT 27-MAR-2024, entry version 214. DE RecName: Full=Immunoglobulin heavy constant mu {ECO:0000303|PubMed:11340299, ECO:0000303|Ref.14}; DE AltName: Full=Ig mu chain C region {ECO:0000305}; DE AltName: Full=Ig mu chain C region BOT {ECO:0000305|PubMed:6425189}; DE AltName: Full=Ig mu chain C region GAL {ECO:0000305|PubMed:4803843}; DE AltName: Full=Ig mu chain C region OU {ECO:0000305|PubMed:4742735}; GN Name=IGHM {ECO:0000303|PubMed:11340299, ECO:0000303|Ref.14}; OS Homo sapiens (Human). OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; OC Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae; OC Homo. OX NCBI_TaxID=9606; RN [1] RP PROTEIN SEQUENCE. RX PubMed=4803843; RA Watanabe S., Barnikol H.U., Horn J., Bertram J., Hilschmann N.; RT "The primary structure of a monoclonal IgM-immunoglobulin (macroglobulin RT Gal.), II: the amino acid sequence of the H-chain (mu-type), subgroup H RT III. Architecture of the complete IgM-molecule."; RL Hoppe-Seyler's Z. Physiol. Chem. 354:1505-1509(1973). RN [2] RP SEQUENCE REVISION. RX PubMed=6777162; DOI=10.1111/j.1432-1033.1980.tb06103.x; RA Mihaesco E., Barnikol-Watanabe S., Barnikol H.U., Mihaesco C., RA Hilschmann N.; RT "The primary structure of the constant part of mu-chain-disease protein RT BOT."; RL Eur. J. Biochem. 111:275-286(1980). RN [3] RP PROTEIN SEQUENCE, DISULFIDE BONDS, GLYCOSYLATION AT ASN-272 AND ASN-279, RP AND GLYCOSYLATION AT ASN-440 (ISOFORM 1). RX PubMed=4742735; DOI=10.1126/science.182.4109.287; RA Putnam F.W., Florent G., Paul C., Shinoda T., Shimizu A.; RT "Complete amino acid sequence of the Mu heavy chain of a human IgM RT immunoglobulin."; RL Science 182:287-291(1973). RN [4] RP NUCLEOTIDE SEQUENCE [GENOMIC DNA] (ISOFORM 1), NUCLEOTIDE SEQUENCE [GENOMIC RP DNA] OF 435-472 (ISOFORM 2), AND VARIANTS LEU-40 AND VAL-414 DEL. RX PubMed=2505237; DOI=10.1093/nar/17.15.6412; RA Dorai H., Gillies S.D.; RT "The complete nucleotide sequence of a human immunoglobulin genomic C mu RT gene."; RL Nucleic Acids Res. 17:6412-6412(1989). RN [5] RP NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 2), AND VARIANT SER-191. RX PubMed=2115996; DOI=10.1093/nar/18.14.4278; RA Friedlander R.M., Nussenzweig M.C., Leder P.; RT "Complete nucleotide sequence of the membrane form of the human IgM heavy RT chain."; RL Nucleic Acids Res. 18:4278-4278(1990). RN [6] RP NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 1). RA Calvo B.F., Schlom J., Kashmiri S.; RT "Complete nucleotide sequence of a cDNA encoding human IgM heavy chain RT constant domains."; RL Submitted (DEC-1990) to the EMBL/GenBank/DDBJ databases. RN [7] RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA] (IMGT ALLELE IGHM*04). RX PubMed=12508121; DOI=10.1038/nature01348; RA Heilig R., Eckenberg R., Petit J.-L., Fonknechten N., Da Silva C., RA Cattolico L., Levy M., Barbe V., De Berardinis V., Ureta-Vidal A., RA Pelletier E., Vico V., Anthouard V., Rowen L., Madan A., Qin S., Sun H., RA Du H., Pepin K., Artiguenave F., Robert C., Cruaud C., Bruels T., RA Jaillon O., Friedlander L., Samson G., Brottier P., Cure S., Segurens B., RA Aniere F., Samain S., Crespeau H., Abbasi N., Aiach N., Boscus D., RA Dickhoff R., Dors M., Dubois I., Friedman C., Gouyvenoux M., James R., RA Madan A., Mairey-Estrada B., Mangenot S., Martins N., Menard M., Oztas S., RA Ratcliffe A., Shaffer T., Trask B., Vacherie B., Bellemere C., Belser C., RA Besnard-Gonnet M., Bartol-Mavel D., Boutard M., Briez-Silla S., RA Combette S., Dufosse-Laurent V., Ferron C., Lechaplais C., Louesse C., RA Muselet D., Magdelenat G., Pateau E., Petit E., Sirvain-Trukniewicz P., RA Trybou A., Vega-Czarny N., Bataille E., Bluet E., Bordelais I., Dubois M., RA Dumont C., Guerin T., Haffray S., Hammadi R., Muanga J., Pellouin V., RA Robert D., Wunderle E., Gauguet G., Roy A., Sainte-Marthe L., Verdier J., RA Verdier-Discala C., Hillier L.W., Fulton L., McPherson J., Matsuda F., RA Wilson R., Scarpelli C., Gyapay G., Wincker P., Saurin W., Quetier F., RA Waterston R., Hood L., Weissenbach J.; RT "The DNA sequence and analysis of human chromosome 14."; RL Nature 421:601-607(2003). RN [8] RP PROTEIN SEQUENCE OF 104-453, AND VARIANT GLY-215. RX PubMed=6425189; DOI=10.1515/bchm2.1984.365.1.105; RA Barnikol-Watanabe S., Mihaesco E., Mihaesco C., Barnikol H.U., RA Hilschmann N.; RT "The primary structure of mu-chain-disease protein BOT. Peculiar amino-acid RT sequence of the N-terminal 42 positions."; RL Hoppe-Seyler's Z. Physiol. Chem. 365:105-118(1984). RN [9] RP NUCLEOTIDE SEQUENCE [MRNA] OF 298-386 AND 436-452 (ISOFORM 1). RX PubMed=6777778; DOI=10.1073/pnas.77.10.6027; RA Dolby T.W., Devuono J., Croce C.M.; RT "Cloning and partial nucleotide sequence of human immunoglobulin mu chain RT cDNA from B cells and mouse-human hybridomas."; RL Proc. Natl. Acad. Sci. U.S.A. 77:6027-6031(1980). RN [10] RP NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 339-472 (ISOFORM 2), AND VARIANTS RP VAL-414 DEL AND ASP-418. RX PubMed=6795593; DOI=10.1093/nar/9.18.4509; RA Rabbitts T.H., Forster A., Milstein C.P.; RT "Human immunoglobulin heavy chain genes: evolutionary comparisons of C mu, RT C delta and C gamma genes and associated switch sequences."; RL Nucleic Acids Res. 9:4509-4524(1981). RN [11] RP FUNCTION. RX PubMed=3137579; DOI=10.1073/pnas.85.18.6914; RA Tisch R., Roifman C.M., Hozumi N.; RT "Functional differences between immunoglobulins M and D expressed on the RT surface of an immature B-cell line."; RL Proc. Natl. Acad. Sci. U.S.A. 85:6914-6918(1988). RN [12] RP SUBUNIT (ISOFORM 1), AND DISULFIDE BOND WITH JCHAIN (ISOFORM 1). RX PubMed=1472500; DOI=10.1021/bi00165a014; RA Frutiger S., Hughes G.J., Paquet N., Luethy R., Jaton J.-C.; RT "Disulfide bond assignment in human J chain and its covalent pairing with RT immunoglobulin M."; RL Biochemistry 31:12643-12647(1992). RN [13] RP NOMENCLATURE. RX PubMed=11340299; DOI=10.1159/000049189; RA Lefranc M.P.; RT "Nomenclature of the human immunoglobulin heavy (IGH) genes."; RL Exp. Clin. Immunogenet. 18:100-116(2001). RN [14] RP NOMENCLATURE. RA Lefranc M.P., Lefranc G.; RT "The Immunoglobulin FactsBook."; RL (In) Lefranc M.P., Lefranc G. (eds.); RL The Immunoglobulin FactsBook., pp.1-458, Academic Press, London. (2001). RN [15] RP FUNCTION (ISOFORM 1), SUBUNIT (ISOFORM 1), AND INTERACTION WITH C1Q RP (ISOFORM 1). RX PubMed=12847249; DOI=10.4049/jimmunol.171.2.812; RA Kishore U., Gupta S.K., Perdikoulis M.V., Kojouharova M.S., Urban B.C., RA Reid K.B.; RT "Modular organization of the carboxyl-terminal, globular head region of RT human C1q A, B, and C chains."; RL J. Immunol. 171:812-820(2003). RN [16] RP GLYCOSYLATION [LARGE SCALE ANALYSIS] AT ASN-46. RC TISSUE=Plasma; RX PubMed=14760718; DOI=10.1002/pmic.200300556; RA Bunkenborg J., Pilch B.J., Podtelejnikov A.V., Wisniewski J.R.; RT "Screening for N-glycosylated proteins by liquid chromatography mass RT spectrometry."; RL Proteomics 4:454-465(2004). RN [17] RP REVIEW. RX PubMed=16895553; DOI=10.1111/j.1365-2567.2006.02386.x; RA Geisberger R., Lamers M., Achatz G.; RT "The riddle of the dual expression of IgM and IgD."; RL Immunology 118:429-437(2006). RN [18] RP REVIEW ON SOMATIC HYPERMUTATION. RX PubMed=17576170; DOI=10.1146/annurev.genet.41.110306.130340; RA Teng G., Papavasiliou F.N.; RT "Immunoglobulin somatic hypermutation."; RL Annu. Rev. Genet. 41:107-120(2007). RN [19] RP FUNCTION (ISOFORM 1), SUBUNIT (ISOFORM 1), AND INTERACTION WITH C1Q RP (ISOFORM 1). RX PubMed=19006321; DOI=10.1021/bi801131h; RA Gadjeva M.G., Rouseva M.M., Zlatarova A.S., Reid K.B., Kishore U., RA Kojouharova M.S.; RT "Interaction of human C1q with IgG and IgM: revisited."; RL Biochemistry 47:13093-13102(2008). RN [20] RP GLYCOSYLATION [LARGE SCALE ANALYSIS] AT ASN-46 AND ASN-279. RC TISSUE=Liver; RX PubMed=19159218; DOI=10.1021/pr8008012; RA Chen R., Jiang X., Sun D., Han G., Wang F., Ye M., Wang L., Zou H.; RT "Glycoproteomics analysis of human liver tissue by combination of multiple RT enzyme digestion and hydrazide chemistry."; RL J. Proteome Res. 8:651-661(2009). RN [21] RP GLYCOSYLATION AT ASN-46 AND ASN-209. RX PubMed=19139490; DOI=10.1074/mcp.m800504-mcp200; RA Jia W., Lu Z., Fu Y., Wang H.P., Wang L.H., Chi H., Yuan Z.F., Zheng Z.B., RA Song L.N., Han H.H., Liang Y.M., Wang J.L., Cai Y., Zhang Y.K., Deng Y.L., RA Ying W.T., He S.M., Qian X.H.; RT "A strategy for precise and large scale identification of core fucosylated RT glycoproteins."; RL Mol. Cell. Proteomics 8:913-923(2009). RN [22] RP REVIEW ON IMMUNOGLOBULINS. RX PubMed=20176268; DOI=10.1016/j.jaci.2009.09.046; RA Schroeder H.W. Jr., Cavacini L.; RT "Structure and function of immunoglobulins."; RL J. Allergy Clin. Immunol. 125:S41-S52(2010). RN [23] RP IDENTIFICATION BY MASS SPECTROMETRY [LARGE SCALE ANALYSIS]. RX PubMed=21269460; DOI=10.1186/1752-0509-5-17; RA Burkard T.R., Planyavsky M., Kaupe I., Breitwieser F.P., Buerckstuemmer T., RA Bennett K.L., Superti-Furga G., Colinge J.; RT "Initial characterization of the human central proteome."; RL BMC Syst. Biol. 5:17-17(2011). RN [24] RP REVIEW ON FUNCTION. RX PubMed=22158414; DOI=10.1038/nri3128; RA McHeyzer-Williams M., Okitsu S., Wang N., McHeyzer-Williams L.; RT "Molecular programming of B cell memory."; RL Nat. Rev. Immunol. 12:24-34(2012). RN [25] RP IDENTIFICATION BY MASS SPECTROMETRY [LARGE SCALE ANALYSIS]. RC TISSUE=Liver; RX PubMed=24275569; DOI=10.1016/j.jprot.2013.11.014; RA Bian Y., Song C., Cheng K., Dong M., Wang F., Huang J., Sun D., Wang L., RA Ye M., Zou H.; RT "An enzyme assisted RP-RPLC approach for in-depth analysis of human liver RT phosphoproteome."; RL J. Proteomics 96:253-262(2014). RN [26] RP FUNCTION (ISOFORM 1), AND SUBUNIT (ISOFORM 1). RX PubMed=28230186; DOI=10.1038/srep42989; RA Lloyd K.A., Wang J., Urban B.C., Czajkowsky D.M., Pleass R.J.; RT "Glycan-independent binding and internalization of human IgM to FCMR, its RT cognate cellular receptor."; RL Sci. Rep. 7:42989-42989(2017). RN [27] RP SUBUNIT (ISOFORM 1). RX PubMed=30324136; DOI=10.1126/sciadv.aau1199; RA Hiramoto E., Tsutsumi A., Suzuki R., Matsuoka S., Arai S., Kikkawa M., RA Miyazaki T.; RT "The IgM pentamer is an asymmetric pentagon with an open groove that binds RT the AIM protein."; RL Sci. Adv. 4:eaau1199-eaau1199(2018). RN [28] RP X-RAY CRYSTALLOGRAPHY (2.70 ANGSTROMS) OF 1-104, AND DISULFIDE BONDS. RX PubMed=11587642; DOI=10.1016/s0969-2126(01)00630-x; RA Graille M., Stura E.A., Housden N.G., Beckingham J.A., Bottomley S.P., RA Beale D., Taussig M.J., Sutton B.J., Gore M.G., Charbonnier J.B.; RT "Complex between Peptostreptococcus magnus protein L and a human antibody RT reveals structural convergence in the interaction modes of Fab binding RT proteins."; RL Structure 9:679-687(2001). RN [29] RP X-RAY CRYSTALLOGRAPHY (2.60 ANGSTROMS) OF 1-106, GLYCOSYLATION AT ASN-46, RP AND DISULFIDE BONDS. RX PubMed=16422668; DOI=10.1042/bj20051739; RA Ramsland P.A., Terzyan S.S., Cloud G., Bourne C.R., Farrugia W., RA Tribbick G., Geysen H.M., Moomaw C.R., Slaughter C.A., Edmundson A.B.; RT "Crystal structure of a glycosylated Fab from an IgM cryoglobulin with RT properties of a natural proteolytic antibody."; RL Biochem. J. 395:473-481(2006). RN [30] RP STRUCTURE BY ELECTRON MICROSCOPY (3.40 ANGSTROMS) OF 106-453 IN COMPLEX RP WITH JCHAIN AND SECRETORY COMPONENT OF PIGR (ISOFORM 1), DISULFIDE BONDS, RP GLYCOSYLATION (ISOFORM 1), SUBUNIT (ISOFORM 1), DOMAIN (ISOFORM 1), AND RP FUNCTION (ISOFORM 1). RX PubMed=32029689; DOI=10.1126/science.aaz5425; RA Li Y., Wang G., Li N., Wang Y., Zhu Q., Chu H., Wu W., Tan Y., Tan Y., RA Yu F., Su X.D., Gao N., Xiao J.; RT "Structural insights into immunoglobulin M."; RL Science 367:1014-1017(2020). RN [31] RP STRUCTURE BY ELECTRON MICROSCOPY (3.30 ANGSTROMS) OF 1-433 (ISOFORM 2) IN RP COMPLEX WITH CD79A AND CD79B, DISULFIDE BONDS, GLYCOSYLATION AT ASN-209; RP ASN-272 AND ASN-279, CHARACTERIZATION OF IGM BCR, FUNCTION (ISOFORM 2), RP SUBUNIT (ISOFORM 2), DOMAIN (ISOFORM 2), AND MUTAGENESIS OF GLN-364; RP GLN-370; THR-407; THR-410; ASP-430; GLU-442; THR-450; PHE-454; PHE-458 AND RP TYR-464. RX PubMed=35981043; DOI=10.1126/science.abo3923; RA Su Q., Chen M., Shi Y., Zhang X., Huang G., Huang B., Liu D., Liu Z., RA Shi Y.; RT "Cryo-EM structure of the human IgM B cell receptor."; RL Science 377:875-880(2022). RN [32] RP STRUCTURE BY ELECTRON MICROSCOPY (3.18 ANGSTROMS) OF 222-453 IN COMPLEX RP WITH FCMR, AND SUBUNIT (ISOFORM 1). RX PubMed=36949194; DOI=10.1038/s41586-023-05835-w; RA Li Y., Shen H., Zhang R., Ji C., Wang Y., Su C., Xiao J.; RT "Immunoglobulin M perception by FcmuR."; RL Nature 615:907-912(2023). RN [33] RP STRUCTURE BY ELECTRON MICROSCOPY (3.10 ANGSTROMS) OF 223-446 (ISOFORM 1) IN RP COMPLEX WITH FCMR, DOMAIN (ISOFORM 1), SUBUNIT (ISOFORM 1), AND FUNCTION RP (ISOFORM 1). RX PubMed=37095205; DOI=10.1038/s41594-023-00985-x; RA Chen Q., Menon R.P., Masino L., Tolar P., Rosenthal P.B.; RT "Structural basis for Fc receptor recognition of immunoglobulin M."; RL Nat. Struct. Mol. Biol. 0:0-0(2023). RN [34] RP INVOLVEMENT IN AGM1. RX PubMed=8890099; DOI=10.1056/nejm199611143352003; RA Yel L., Minegishi Y., Coustan-Smith E., Buckley R.H., Trubel H., RA Pachman L.M., Kitchingman G.R., Campana D., Rohrer J., Conley M.E.; RT "Mutations in the mu heavy-chain gene in patients with RT agammaglobulinemia."; RL N. Engl. J. Med. 335:1486-1493(1996). CC -!- FUNCTION: Constant region of immunoglobulin heavy chains. CC Immunoglobulins, also known as antibodies, are membrane-bound or CC secreted glycoproteins produced by B lymphocytes. In the recognition CC phase of humoral immunity, the membrane-bound immunoglobulins serve as CC receptors which, upon binding of a specific antigen, trigger the clonal CC expansion and differentiation of B lymphocytes into immunoglobulins- CC secreting plasma cells. Secreted immunoglobulins mediate the effector CC phase of humoral immunity, which results in the elimination of bound CC antigens (PubMed:22158414, PubMed:20176268). The antigen binding site CC is formed by the variable domain of one heavy chain, together with that CC of its associated light chain. Thus, each immunoglobulin has two CC antigen binding sites with remarkable affinity for a particular CC antigen. The variable domains are assembled by a process called V-(D)-J CC rearrangement and can then be subjected to somatic hypermutations CC which, after exposure to antigen and selection, allow affinity CC maturation for a particular antigen (PubMed:17576170, PubMed:20176268). CC {ECO:0000303|PubMed:17576170, ECO:0000303|PubMed:20176268, CC ECO:0000303|PubMed:22158414}. CC -!- FUNCTION: [Isoform 1]: Constant region of secreted IgM (sIgM), also CC known as the Fc region of IgM antibody. Able to multimerize, forms high CC order polymers, mainly pentamers and occasionally hexamers, providing CC for multivalency and high avidity recognition of antigens CC (PubMed:32029689, PubMed:37095205). Natural sIgM are polyreactive and CC recognize conserved self- and pathogen-derived structures, whereas CC immune sIgM are secreted only upon exposure to pathogens and are CC antigen-specific. Both natural and immune sIgM are required for an CC efficient humoral immune response to infection (By similarity). CC Mediates sIgM effector functions mostly via Fc receptors and the CC complement system. On lymphoid cells binds high-affinity Fc receptor CC FCMR and promotes induction of an efficient neutralizing IgG response CC while maintaining tolerance to self-antigens. Recruits C1q complement CC component to initiate the classical complement pathway, facilitating CC the recognition and neutralization of pathogens by the host. Together CC with C1q and mannose-binding lectin promotes the phagocytosis of CC apoptotic cells by macrophages, ensuring the clearance of potential CC autoimmune epitopes from tissues (PubMed:12847249, PubMed:19006321, CC PubMed:28230186, PubMed:32029689) (By similarity). Involved in mucosal CC immunity. It is transported by transcytosis across mucosal epithelium CC by PIGR and secreted on the apical side in complex with PIGR secretory CC component to scan mucosal lining for pathogens. IgM-antigen complexes CC undergo FCMR-mediated retrotranscytosis across mucosal M cells toward CC antigen-presenting cells in mucosal lymphoid tissues (PubMed:32029689) CC (By similarity). {ECO:0000250|UniProtKB:P01872, CC ECO:0000269|PubMed:12847249, ECO:0000269|PubMed:19006321, CC ECO:0000269|PubMed:28230186, ECO:0000269|PubMed:32029689, CC ECO:0000269|PubMed:37095205}. CC -!- FUNCTION: [Isoform 2]: Constant region of membrane-bound IgM, part of CC the B cell receptor complex (BCR). IgM BCR provides constitutive tonic CC signaling for B cell survival. Mediates pre-BCR signaling that CC regulates B cell selection and rearrangement of Ig genes via allelic CC exclusion. {ECO:0000250|UniProtKB:P01872, ECO:0000269|PubMed:35981043}. CC -!- SUBUNIT: The basic structural unit of both sIgM and mIgM molecules CC consists of two identical heavy chains and two identical light chains; CC disulfide-linked. N-terminal variable regions of the heavy and light CC chains form the antigen binding sites, whereas the C-terminal constant CC regions of the heavy chains interact with immune receptors to mediate CC effector functions. {ECO:0000269|PubMed:32029689, CC ECO:0000269|PubMed:35981043}. CC -!- SUBUNIT: [Isoform 1]: Part of IgM antibody. Forms high order oligomers, CC homopentamers stabilized by the JCHAIN and homohexamers that lack CC JCHAIN. The oligomerization amplifies an inherently low affinity of IgM CC antibodies for the antigen by multi-point attachment (avidity). CC Adjacent IgM protomers associate via interchain disulfide links to form CC an asymmetric pentameric structure with a 50 degree gap. A single copy CC of JCHAIN is covalently linked to the first and the fifth IgM monomers CC via interchain disulfide bonds thus closing the pentamer ring. Only CC JCHAIN-containing IgM binds PIGR secretory component (via D1-CDR1 CC region); this interaction is a prerequisite for IgM transcytosis across CC mucosal epithelium (PubMed:1472500, PubMed:30324136, PubMed:32029689, CC PubMed:36949194). Pentameric sIgM interacts (via CH4 domain) with FCRM CC (via Ig-like domain); the interaction is glycan-independent and CC multivalent theoretically involving up to eight binding sites for the CC IgM pentamer (PubMed:37095205, PubMed:36949194, PubMed:28230186). CC Interacts with FCAMR; this interaction facilitates the endocytosis of CC IgM-coated microbes or IgM-antigen immune complexes (By similarity). CC Antigen-bound IgM (via the Fc region) binds to globular domains of C1q CC component of the complement system, all three modules C1QA, C1QB and CC C1QC being involved in IgM binding; this interaction is multivalent CC (PubMed:12847249, PubMed:19006321). Pentameric sIgM (via Fc region) CC interacts with CD5L (via SRCR2) through interchain disulfide-linkages; CC this interaction protects CD5L from renal excretion and provides for CC high levels of CD5L in circulation (By similarity). CC {ECO:0000250|UniProtKB:P01872, ECO:0000269|PubMed:12847249, CC ECO:0000269|PubMed:1472500, ECO:0000269|PubMed:19006321, CC ECO:0000269|PubMed:28230186, ECO:0000269|PubMed:30324136, CC ECO:0000269|PubMed:32029689, ECO:0000269|PubMed:36949194, CC ECO:0000269|PubMed:37095205}. CC -!- SUBUNIT: [Isoform 2]: Part of IgM B cell receptor complex on pre-B CC cells, immature and mature B cells. The BCR complex consists of one CC membrane-bound IgM molecule responsible for antigen binding, non- CC covalently associated with CD79A and CD79B signaling chains. CC {ECO:0000269|PubMed:35981043}. CC -!- SUBCELLULAR LOCATION: [Isoform 1]: Secreted. Note=During CC differentiation, B-lymphocytes switch from expression of membrane-bound CC IgM to secretion of IgM. {ECO:0000305}. CC -!- SUBCELLULAR LOCATION: [Isoform 2]: Cell membrane; Single-pass membrane CC protein {ECO:0000255}. CC -!- ALTERNATIVE PRODUCTS: CC Event=Alternative splicing; Named isoforms=2; CC Name=2; Synonyms=Membrane-bound, mIgM; CC IsoId=P01871-2; Sequence=Displayed; CC Name=1; Synonyms=Secreted, sIgM; CC IsoId=P01871-1; Sequence=VSP_061838; CC -!- DOMAIN: [Isoform 1]: The C-terminal beta-strands mediate sIgM CC oligomerization. The region encompassing residues Tyr-437 to Met-453 in CC each protomer forms a beta-strand, and the ten strands arrange in two CC five-stranded parallel beta-sheets packed in an antiparallel way, CC reminiscent of beta-sheet amyloid structures. CC {ECO:0000269|PubMed:32029689}. CC -!- DOMAIN: [Isoform 1]: The CH4 domains of pentameric IgM mediate CC multivalent interactions with the Ig-like domain of FCMR, thereby CC facilitating receptor clustering and signaling. CC {ECO:0000269|PubMed:37095205}. CC -!- DOMAIN: [Isoform 2]: The transmembrane helices of two heavy chains and CC CD79A and CD79B chains assembly in a four-helix bundle structure that CC appears to be conserved among different BCR isotypes. CC {ECO:0000269|PubMed:35981043}. CC -!- PTM: N-glycosylated; important for IgM secretion and its localization CC at the plasma membrane. The interaction with FCMR is glycan- CC independent. {ECO:0000269|PubMed:28230186, ECO:0000269|PubMed:32029689, CC ECO:0000269|PubMed:35981043}. CC -!- POLYMORPHISM: There are several alleles. The sequence shown is that of CC IMGT allele IGHM*04. {ECO:0000305}. CC -!- DISEASE: Agammaglobulinemia 1, autosomal recessive (AGM1) [MIM:601495]: CC A primary immunodeficiency characterized by profoundly low or absent CC serum antibodies and low or absent circulating B cells due to an early CC block of B-cell development. Affected individuals develop severe CC infections in the first years of life. {ECO:0000269|PubMed:8890099}. CC Note=The disease is caused by variants affecting the gene represented CC in this entry. CC -!- CAUTION: For an example of a full-length immunoglobulin mu heavy chain CC see AC P0DOX6. {ECO:0000305}. CC -!- SEQUENCE CAUTION: CC Sequence=CAA33065.1; Type=Erroneous initiation; Note=Truncated N-terminus.; Evidence={ECO:0000305}; CC Sequence=CAA33069.1; Type=Erroneous initiation; Note=Truncated N-terminus.; Evidence={ECO:0000305}; CC Sequence=CAA33071.1; Type=Erroneous gene model prediction; Evidence={ECO:0000305}; CC Sequence=CAA34971.1; Type=Erroneous initiation; Note=Extended N-terminus.; Evidence={ECO:0000305}; CC Sequence=CAE82013.1; Type=Erroneous initiation; Note=Truncated N-terminus.; Evidence={ECO:0000305}; CC Sequence=CAE82014.1; Type=Erroneous initiation; Note=Truncated N-terminus.; Evidence={ECO:0000305}; CC -!- WEB RESOURCE: Name=IGHMbase; Note=IGHM mutation db; CC URL="http://structure.bmc.lu.se/idbase/IGHMbase/"; CC --------------------------------------------------------------------------- CC Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms CC Distributed under the Creative Commons Attribution (CC BY 4.0) License CC --------------------------------------------------------------------------- DR EMBL; X14940; CAE82013.1; ALT_INIT; Genomic_DNA. DR EMBL; X14940; CAE82014.1; ALT_INIT; Genomic_DNA. DR EMBL; X14940; CAA33069.1; ALT_INIT; Genomic_DNA. DR EMBL; X14940; CAA33070.1; -; Genomic_DNA. DR EMBL; X14940; CAA33071.1; ALT_SEQ; Genomic_DNA. DR EMBL; X14939; CAA33065.1; ALT_INIT; Genomic_DNA. DR EMBL; X17115; CAA34971.1; ALT_INIT; mRNA. DR EMBL; X57086; CAB37838.1; -; mRNA. DR EMBL; AC244226; -; NOT_ANNOTATED_CDS; Genomic_DNA. DR EMBL; AC245166; -; NOT_ANNOTATED_CDS; Genomic_DNA. DR EMBL; AC246787; -; NOT_ANNOTATED_CDS; Genomic_DNA. DR EMBL; AC247036; -; NOT_ANNOTATED_CDS; Genomic_DNA. DR EMBL; K01310; AAB59422.1; -; Genomic_DNA. DR PIR; A02163; MHHUBT. DR PIR; S14683; S14683. DR PIR; S16510; MHHUM. DR PDB; 1HEZ; X-ray; 2.70 A; B/D=1-104. DR PDB; 2AGJ; X-ray; 2.60 A; H=1-105. DR PDB; 2RCJ; X-ray; -; C/D/G/H/K/L/O/P/S/T=1-326. DR PDB; 6KXS; EM; 3.40 A; A/B/C/D/E/F/G/H/K/L=106-453. DR PDB; 7K0C; EM; 3.30 A; A/B/E/F/G/H/I/J/K/L=103-453. DR PDB; 7QDO; EM; 3.60 A; A/B=105-433. DR PDB; 7WSP; EM; 4.09 A; B/D=106-433. DR PDB; 7XQ8; EM; 3.30 A; C/v=1-433. DR PDB; 7XT6; EM; 3.63 A; B/D=109-433. DR PDB; 7Y09; EM; 3.71 A; A/B/C/D/E/F/G/H/K/L=106-453. DR PDB; 7Y0H; EM; 3.56 A; A/B/C/D/E/F/G/H/K/L=106-453. DR PDB; 7Y0J; EM; 3.62 A; A/B/C/D/E/F/G/H/K/L=106-453. DR PDB; 7YG2; EM; 3.32 A; A/B/C/D/E/F/G/H/K/L=106-453. DR PDB; 7YSG; EM; 3.18 A; A/B/C/D/E/F/G/H/K/L=222-453. DR PDB; 7YTC; EM; 3.39 A; A/B/C/D/E/F/G/H/K/L=222-453. DR PDB; 7YTD; EM; 3.71 A; A/B/C/D/E/F/G/H/K/L=222-452. DR PDB; 8ADY; EM; 5.20 A; C/D/E/F/G/K/N/O/R/T=105-453. DR PDB; 8ADZ; EM; 6.70 A; E/F/G/K/M/N/O/Q/R/S=105-453. DR PDB; 8AE0; EM; 7.10 A; C/D/E/F/G/K/N/O/R/T=105-453. DR PDB; 8AE2; EM; 8.50 A; C/D/E/F/G/K/N/O/R/T=105-453. DR PDB; 8AE3; EM; 6.80 A; C/D/E/F/G/K/N/O/R/T=105-453. DR PDB; 8BPF; EM; 3.50 A; A/B/C/D/E/F/G/H/K/L=106-453. DR PDB; 8BPG; EM; 3.10 A; C/D/E/F=106-453. DR PDB; 8GZN; EM; 3.60 A; A/B/C/D/E/F/G/H/K/L=1-453. DR PDBsum; 1HEZ; -. DR PDBsum; 2AGJ; -. DR PDBsum; 2RCJ; -. DR PDBsum; 6KXS; -. DR PDBsum; 7K0C; -. DR PDBsum; 7QDO; -. DR PDBsum; 7WSP; -. DR PDBsum; 7XQ8; -. DR PDBsum; 7XT6; -. DR PDBsum; 7Y09; -. DR PDBsum; 7Y0H; -. DR PDBsum; 7Y0J; -. DR PDBsum; 7YG2; -. DR PDBsum; 7YSG; -. DR PDBsum; 7YTC; -. DR PDBsum; 7YTD; -. DR PDBsum; 8ADY; -. DR PDBsum; 8ADZ; -. DR PDBsum; 8AE0; -. DR PDBsum; 8AE2; -. DR PDBsum; 8AE3; -. DR PDBsum; 8BPF; -. DR PDBsum; 8BPG; -. DR PDBsum; 8GZN; -. DR AlphaFoldDB; P01871; -. DR EMDB; EMD-0782; -. DR EMDB; EMD-13922; -. DR EMDB; EMD-15375; -. DR EMDB; EMD-15376; -. DR EMDB; EMD-15377; -. DR EMDB; EMD-15379; -. DR EMDB; EMD-15380; -. DR EMDB; EMD-16150; -. DR EMDB; EMD-16151; -. DR EMDB; EMD-16152; -. DR EMDB; EMD-22591; -. DR EMDB; EMD-32763; -. DR EMDB; EMD-33440; -. DR EMDB; EMD-33538; -. DR EMDB; EMD-33542; -. DR EMDB; EMD-33547; -. DR EMDB; EMD-33805; -. DR EMDB; EMD-34074; -. DR EMDB; EMD-34085; -. DR EMDB; EMD-34086; -. DR EMDB; EMD-34399; -. DR SMR; P01871; -. DR ComplexPortal; CPX-6911; IgM - Ig kappa immunoglobulin complex, constant regions. DR ComplexPortal; CPX-6922; IgM - Ig lambda 1 immunoglobulin complex, constant regions. DR ComplexPortal; CPX-6923; IgM - Ig lambda 2 immunoglobulin complex, constant regions. DR ComplexPortal; CPX-6925; IgM - Ig lambda 3 immunoglobulin complex, constant regions. DR ComplexPortal; CPX-6926; IgM - Ig lambda 6 immunoglobulin complex, constant regions. DR ComplexPortal; CPX-6927; IgM - Ig lambda 7 immunoglobulin complex, constant regions. DR CORUM; P01871; -. DR IntAct; P01871; 67. DR MINT; P01871; -. DR DrugBank; DB01593; Zinc. DR DrugBank; DB14487; Zinc acetate. DR IMGT_GENE-DB; IGHM; -. DR CarbonylDB; P01871; -. DR GlyConnect; 280; 204 N-Linked glycans (6 sites). DR GlyCosmos; P01871; 6 sites, 237 glycans. DR GlyGen; P01871; 6 sites, 228 N-linked glycans (5 sites), 1 O-linked glycan (1 site). DR iPTMnet; P01871; -. DR PhosphoSitePlus; P01871; -. DR SwissPalm; P01871; -. DR BioMuta; IGHM; -. DR DMDM; 193806374; -. DR CPTAC; non-CPTAC-2676; -. DR jPOST; P01871; -. DR MassIVE; P01871; -. DR PeptideAtlas; P01871; -. DR PRIDE; P01871; -. DR ProteomicsDB; 51498; -. [P01871-1] DR ProteomicsDB; 51499; -. [P01871-2] DR Pumba; P01871; -. DR ABCD; P01871; 17 sequenced antibodies. DR Ensembl; ENST00000390559.6; ENSP00000375001.2; ENSG00000211899.10. [P01871-1] DR Ensembl; ENST00000626472.2; ENSP00000485962.2; ENSG00000282657.3. [P01871-1] DR Ensembl; ENST00000637539.2; ENSP00000490253.1; ENSG00000211899.10. [P01871-2] DR UCSC; uc059gdp.1; human. DR AGR; HGNC:5541; -. DR GeneCards; IGHM; -. DR HGNC; HGNC:5541; IGHM. DR HPA; ENSG00000211899; Group enriched (intestine, lymphoid tissue). DR MalaCards; IGHM; -. DR MIM; 147020; gene. DR MIM; 601495; phenotype. DR neXtProt; NX_P01871; -. DR OpenTargets; ENSG00000211899; -. DR Orphanet; 33110; Autosomal agammaglobulinemia. DR VEuPathDB; HostDB:ENSG00000211899; -. DR GeneTree; ENSGT00940000161491; -. DR InParanoid; P01871; -. DR OMA; CEVHSTE; -. DR PhylomeDB; P01871; -. DR PathwayCommons; P01871; -. DR Reactome; R-HSA-202733; Cell surface interactions at the vascular wall. DR Reactome; R-HSA-5690714; CD22 mediated BCR regulation. DR Reactome; R-HSA-9679191; Potential therapeutics for SARS. DR Reactome; R-HSA-983695; Antigen activates B Cell Receptor (BCR) leading to generation of second messengers. DR SignaLink; P01871; -. DR SIGNOR; P01871; -. DR ChiTaRS; IGHM; human. DR EvolutionaryTrace; P01871; -. DR Pharos; P01871; Tbio. DR PRO; PR:P01871; -. DR Proteomes; UP000005640; Chromosome 14. DR RNAct; P01871; Protein. DR Bgee; ENSG00000211899; Expressed in spleen and 113 other cell types or tissues. DR GO; GO:0072562; C:blood microparticle; HDA:UniProtKB. DR GO; GO:0009986; C:cell surface; IDA:UniProtKB. DR GO; GO:0070062; C:extracellular exosome; HDA:UniProtKB. DR GO; GO:0005615; C:extracellular space; IDA:UniProtKB. DR GO; GO:0071757; C:hexameric IgM immunoglobulin complex; IDA:UniProtKB. DR GO; GO:0071755; C:IgM B cell receptor complex; IDA:UniProtKB. DR GO; GO:0071753; C:IgM immunoglobulin complex; NAS:ComplexPortal. DR GO; GO:0042571; C:immunoglobulin complex, circulating; IBA:GO_Central. DR GO; GO:0071756; C:pentameric IgM immunoglobulin complex; IDA:UniProtKB. DR GO; GO:0005886; C:plasma membrane; TAS:Reactome. DR GO; GO:0003823; F:antigen binding; IBA:GO_Central. DR GO; GO:0002250; P:adaptive immune response; IDA:UniProtKB. DR GO; GO:0019731; P:antibacterial humoral response; IDA:UniProtKB. DR GO; GO:0050853; P:B cell receptor signaling pathway; NAS:ComplexPortal. DR GO; GO:0006958; P:complement activation, classical pathway; IBA:GO_Central. DR GO; GO:0050829; P:defense response to Gram-negative bacterium; IDA:UniProtKB. DR GO; GO:0045087; P:innate immune response; IDA:UniProtKB. DR GO; GO:0002331; P:pre-B cell allelic exclusion; ISS:UniProtKB. DR CDD; cd21819; IgC1_CH1_IgM; 1. DR CDD; cd16093; IgC1_CH2_Mu; 1. DR CDD; cd07696; IgC1_CH3_IgAEM_CH2_IgG; 1. DR CDD; cd05768; IgC1_CH3_IgAGD_CH4_IgAEM; 1. DR Gene3D; 2.60.40.10; Immunoglobulins; 4. DR InterPro; IPR007110; Ig-like_dom. DR InterPro; IPR036179; Ig-like_dom_sf. DR InterPro; IPR013783; Ig-like_fold. DR InterPro; IPR003006; Ig/MHC_CS. DR InterPro; IPR003597; Ig_C1-set. DR PANTHER; PTHR23411:SF35; IMMUNOGLOBULIN HEAVY CONSTANT MU; 1. DR PANTHER; PTHR23411; TAPASIN; 1. DR Pfam; PF07654; C1-set; 4. DR SMART; SM00407; IGc1; 4. DR SUPFAM; SSF48726; Immunoglobulin; 4. DR PROSITE; PS50835; IG_LIKE; 4. DR PROSITE; PS00290; IG_MHC; 3. DR UCD-2DPAGE; P01871; -. PE 1: Evidence at protein level; KW 3D-structure; Adaptive immunity; Alternative splicing; Cell membrane; KW Direct protein sequencing; Disulfide bond; Glycoprotein; Immunity; KW Immunoglobulin; Immunoglobulin domain; Membrane; Reference proteome; KW Secreted; Transmembrane; Transmembrane helix. FT CHAIN <1..474 FT /note="Immunoglobulin heavy constant mu" FT /id="PRO_0000153619" FT TOPO_DOM 1..450 FT /note="Extracellular" FT /evidence="ECO:0000305" FT TRANSMEM 451..471 FT /note="Helical" FT /evidence="ECO:0000255" FT TOPO_DOM 472..474 FT /note="Cytoplasmic" FT /evidence="ECO:0000305" FT DOMAIN 6..102 FT /note="Ig-like 1" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00114" FT DOMAIN 111..211 FT /note="Ig-like 2" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00114" FT DOMAIN 229..319 FT /note="Ig-like 3" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00114" FT DOMAIN 329..430 FT /note="Ig-like 4" FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00114" FT REGION 1..105 FT /note="CH1" FT REGION 106..217 FT /note="CH2" FT REGION 218..323 FT /note="CH3" FT REGION 324..452 FT /note="CH4" FT CARBOHYD 46 FT /note="N-linked (GlcNAc...) (complex) asparagine" FT /evidence="ECO:0000269|PubMed:14760718, FT ECO:0000269|PubMed:16422668, ECO:0000269|PubMed:19139490, FT ECO:0000269|PubMed:19159218, ECO:0007744|PDB:2AGJ" FT CARBOHYD 209 FT /note="N-linked (GlcNAc...) (complex) asparagine" FT /evidence="ECO:0000269|PubMed:19139490, FT ECO:0000269|PubMed:35981043, ECO:0007744|PDB:7XQ8" FT CARBOHYD 272 FT /note="N-linked (GlcNAc...) asparagine" FT /evidence="ECO:0000269|PubMed:35981043, FT ECO:0000269|PubMed:4742735, ECO:0007744|PDB:7XQ8" FT CARBOHYD 279 FT /note="N-linked (GlcNAc...) asparagine" FT /evidence="ECO:0000269|PubMed:19159218, FT ECO:0000269|PubMed:35981043, ECO:0000269|PubMed:4742735, FT ECO:0007744|PDB:7XQ8" FT DISULFID 14 FT /note="Interchain (with light chain)" FT /evidence="ECO:0000269|PubMed:4742735" FT DISULFID 28..88 FT /evidence="ECO:0000269|PubMed:11587642, FT ECO:0000269|PubMed:16422668, ECO:0007744|PDB:1HEZ, FT ECO:0007744|PDB:2AGJ" FT DISULFID 134..197 FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00114, FT ECO:0000269|PubMed:35981043, ECO:0007744|PDB:7XQ8" FT DISULFID 214 FT /note="Interchain (with heavy chain)" FT /evidence="ECO:0000269|PubMed:4742735" FT DISULFID 244..303 FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00114, FT ECO:0000269|PubMed:32029689, ECO:0000269|PubMed:35981043, FT ECO:0007744|PDB:6KXS, ECO:0007744|PDB:7XQ8" FT DISULFID 291 FT /note="Interchain (with heavy chain of another subunit)" FT /evidence="ECO:0000269|PubMed:32029689, FT ECO:0000269|PubMed:4742735, ECO:0007744|PDB:6KXS" FT DISULFID 351..413 FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00114, FT ECO:0000269|PubMed:32029689, ECO:0000269|PubMed:35981043, FT ECO:0007744|PDB:6KXS, ECO:0007744|PDB:7XQ8" FT DISULFID 413 FT /note="Interchain (with C-194 of CD5L)" FT /evidence="ECO:0000250|UniProtKB:P01872" FT VAR_SEQ 434..474 FT /note="EGEVSADEEGFENLWATASTFIVLFLLSLFYSTTVTLFKVK -> GKPTLYN FT VSLVMSDTAGTCY (in isoform 1)" FT /id="VSP_061838" FT VARIANT 40 FT /note="F -> L (in IMGT allele IGHM*01)" FT /evidence="ECO:0000269|PubMed:2505237" FT /id="VAR_077893" FT VARIANT 191 FT /note="G -> S (in IMGT allele IGHM*03)" FT /evidence="ECO:0000269|PubMed:2115996" FT /id="VAR_003903" FT VARIANT 215 FT /note="V -> G (in dbSNP:rs12365)" FT /evidence="ECO:0000269|PubMed:6425189" FT /id="VAR_003904" FT VARIANT 414 FT /note="Missing (in IMGT allele IGHM*01 IMGT allele FT IGHM*02)" FT /evidence="ECO:0000269|PubMed:2505237, FT ECO:0000269|PubMed:6795593" FT /id="VAR_077894" FT VARIANT 418 FT /note="E -> D (in IMGT allele IGHM*02)" FT /evidence="ECO:0000269|PubMed:6795593" FT /id="VAR_077895" FT MUTAGEN 364 FT /note="Q->A: Has no effect on IgMBCR assembly; when FT associated with A-470." FT /evidence="ECO:0000269|PubMed:35981043" FT MUTAGEN 370 FT /note="Q->A: Has no effect on IgMBCR assembly; when FT associated with A-364." FT /evidence="ECO:0000269|PubMed:35981043" FT MUTAGEN 407 FT /note="T->A: Has little effect on IgMBCR assembly; when FT associated with A-410." FT /evidence="ECO:0000269|PubMed:35981043" FT MUTAGEN 410 FT /note="T->A: Has little effect on IgMBCR assembly; when FT associated with A-407." FT /evidence="ECO:0000269|PubMed:35981043" FT MUTAGEN 430 FT /note="D->A: Blocks IgMBCR assembly; when associated with FT A-442." FT /evidence="ECO:0000269|PubMed:35981043" FT MUTAGEN 442 FT /note="E->A: Blocks IgMBCR assembly; when associated with FT A-430." FT /evidence="ECO:0000269|PubMed:35981043" FT MUTAGEN 450 FT /note="T->A: Blocks IgMBCR assembly; when associated with FT A-464." FT /evidence="ECO:0000269|PubMed:35981043" FT MUTAGEN 454 FT /note="F->W: Blocks IgMBCR assembly." FT /evidence="ECO:0000269|PubMed:35981043" FT MUTAGEN 458 FT /note="F->W: Blocks IgMBCR assembly." FT /evidence="ECO:0000269|PubMed:35981043" FT MUTAGEN 464 FT /note="Y->A: Blocks IgMBCR assembly; when associated with FT A-450." FT /evidence="ECO:0000269|PubMed:35981043" FT CONFLICT 128 FT /note="R -> RS (in Ref. 5; CAA34971)" FT /evidence="ECO:0000305" FT CONFLICT 145 FT /note="Q -> E (in Ref. 8; AA sequence)" FT /evidence="ECO:0000305" FT CONFLICT 163..165 FT /note="QVQ -> EVE (in Ref. 8; AA sequence)" FT /evidence="ECO:0000305" FT CONFLICT 220 FT /note="T -> I (in Ref. 6; CAB37838)" FT /evidence="ECO:0000305" FT CONFLICT 263 FT /note="N -> D (in Ref. 8; AA sequence)" FT /evidence="ECO:0000305" FT CONFLICT 296 FT /note="N -> D (in Ref. 8; AA sequence)" FT /evidence="ECO:0000305" FT CONFLICT 438 FT /note="S -> N (in Ref. 10; AAB59422)" FT /evidence="ECO:0000305" FT CONFLICT 440 FT /note="D -> E (in Ref. 10; AAB59422)" FT /evidence="ECO:0000305" FT CONFLICT 449 FT /note="A -> T (in Ref. 10; AAB59422)" FT /evidence="ECO:0000305" FT NON_TER 1 FT STRAND 10..12 FT /evidence="ECO:0007829|PDB:2AGJ" FT STRAND 22..28 FT /evidence="ECO:0007829|PDB:2AGJ" FT STRAND 31..36 FT /evidence="ECO:0007829|PDB:2AGJ" FT STRAND 40..43 FT /evidence="ECO:0007829|PDB:2AGJ" FT STRAND 45..49 FT /evidence="ECO:0007829|PDB:1HEZ" FT STRAND 53..55 FT /evidence="ECO:0007829|PDB:1HEZ" FT STRAND 59..61 FT /evidence="ECO:0007829|PDB:2AGJ" FT STRAND 64..66 FT /evidence="ECO:0007829|PDB:2AGJ" FT STRAND 69..74 FT /evidence="ECO:0007829|PDB:2AGJ" FT HELIX 75..78 FT /evidence="ECO:0007829|PDB:2AGJ" FT STRAND 79..82 FT /evidence="ECO:0007829|PDB:2AGJ" FT STRAND 85..90 FT /evidence="ECO:0007829|PDB:2AGJ" FT STRAND 100..102 FT /evidence="ECO:0007829|PDB:2AGJ" FT STRAND 112..117 FT /evidence="ECO:0007829|PDB:7XQ8" FT TURN 125..128 FT /evidence="ECO:0007829|PDB:7XQ8" FT STRAND 129..137 FT /evidence="ECO:0007829|PDB:7XQ8" FT STRAND 145..150 FT /evidence="ECO:0007829|PDB:7XQ8" FT STRAND 170..173 FT /evidence="ECO:0007829|PDB:7XQ8" FT STRAND 176..185 FT /evidence="ECO:0007829|PDB:7XQ8" FT HELIX 186..189 FT /evidence="ECO:0007829|PDB:7XQ8" FT TURN 190..192 FT /evidence="ECO:0007829|PDB:7XQ8" FT STRAND 195..201 FT /evidence="ECO:0007829|PDB:7XQ8" FT STRAND 204..210 FT /evidence="ECO:0007829|PDB:7XQ8" FT STRAND 223..227 FT /evidence="ECO:0007829|PDB:8BPG" FT HELIX 231..237 FT /evidence="ECO:0007829|PDB:8BPG" FT STRAND 241..248 FT /evidence="ECO:0007829|PDB:8BPG" FT STRAND 257..264 FT /evidence="ECO:0007829|PDB:8BPG" FT STRAND 266..269 FT /evidence="ECO:0007829|PDB:7YSG" FT STRAND 270..274 FT /evidence="ECO:0007829|PDB:7XQ8" FT TURN 278..280 FT /evidence="ECO:0007829|PDB:8BPG" FT STRAND 282..286 FT /evidence="ECO:0007829|PDB:7K0C" FT HELIX 292..297 FT /evidence="ECO:0007829|PDB:8BPG" FT STRAND 301..305 FT /evidence="ECO:0007829|PDB:8BPG" FT STRAND 310..312 FT /evidence="ECO:0007829|PDB:7YSG" FT STRAND 314..318 FT /evidence="ECO:0007829|PDB:8BPG" FT STRAND 330..334 FT /evidence="ECO:0007829|PDB:8BPG" FT HELIX 340..342 FT /evidence="ECO:0007829|PDB:8BPG" FT STRAND 343..345 FT /evidence="ECO:0007829|PDB:8BPG" FT STRAND 347..359 FT /evidence="ECO:0007829|PDB:8BPG" FT STRAND 362..367 FT /evidence="ECO:0007829|PDB:8BPG" FT HELIX 374..376 FT /evidence="ECO:0007829|PDB:8BPG" FT STRAND 377..379 FT /evidence="ECO:0007829|PDB:8BPG" FT STRAND 386..388 FT /evidence="ECO:0007829|PDB:8BPG" FT STRAND 392..400 FT /evidence="ECO:0007829|PDB:8BPG" FT HELIX 402..406 FT /evidence="ECO:0007829|PDB:8BPG" FT STRAND 411..416 FT /evidence="ECO:0007829|PDB:8BPG" FT STRAND 420..423 FT /evidence="ECO:0007829|PDB:8BPG" FT STRAND 426..429 FT /evidence="ECO:0007829|PDB:8BPG" FT STRAND 431..434 FT /evidence="ECO:0007829|PDB:8BPG" FT STRAND 437..440 FT /evidence="ECO:0007829|PDB:7YSG" FT STRAND 442..446 FT /evidence="ECO:0007829|PDB:7YSG" FT STRAND 448..450 FT /evidence="ECO:0007829|PDB:8BPF" FT REGION P01871-1:437..453 FT /note="Important for IgM oligomerization" FT /evidence="ECO:0000269|PubMed:32029689" FT CARBOHYD P01871-1:440 FT /note="N-linked (GlcNAc...) asparagine" FT /evidence="ECO:0000269|PubMed:32029689, FT ECO:0000269|PubMed:4742735, ECO:0007744|PDB:6KXS" FT /id="CAR_000219" FT DISULFID P01871-1:452 FT /note="Interchain (with C-37 or C-91 of JCHAIN)" FT /evidence="ECO:0000269|PubMed:1472500, FT ECO:0000269|PubMed:32029689, ECO:0007744|PDB:6KXS" SQ SEQUENCE 474 AA; 51924 MW; 7A66A47C8810BDF1 CRC64; GSASAPTLFP LVSCENSPSD TSSVAVGCLA QDFLPDSITF SWKYKNNSDI SSTRGFPSVL RGGKYAATSQ VLLPSKDVMQ GTDEHVVCKV QHPNGNKEKN VPLPVIAELP PKVSVFVPPR DGFFGNPRKS KLICQATGFS PRQIQVSWLR EGKQVGSGVT TDQVQAEAKE SGPTTYKVTS TLTIKESDWL GQSMFTCRVD HRGLTFQQNA SSMCVPDQDT AIRVFAIPPS FASIFLTKST KLTCLVTDLT TYDSVTISWT RQNGEAVKTH TNISESHPNA TFSAVGEASI CEDDWNSGER FTCTVTHTDL PSPLKQTISR PKGVALHRPD VYLLPPAREQ LNLRESATIT CLVTGFSPAD VFVQWMQRGQ PLSPEKYVTS APMPEPQAPG RYFAHSILTV SEEEWNTGET YTCVVAHEAL PNRVTERTVD KSTEGEVSAD EEGFENLWAT ASTFIVLFLL SLFYSTTVTL FKVK //