Immunoglobulin heavy constant delta (IGHD)

The protein contains 384 amino acids for an estimated molecular weight of 42353 Da.

 

Constant region of immunoglobulin heavy chains. Immunoglobulins, also known as antibodies, are membrane-bound or secreted glycoproteins produced by B lymphocytes. In the recognition phase of humoral immunity, the membrane-bound immunoglobulins serve as receptors which, upon binding of a specific antigen, trigger the clonal expansion and differentiation of B lymphocytes into immunoglobulins-secreting plasma cells. Secreted immunoglobulins mediate the effector phase of humoral immunity, which results in the elimination of bound antigens (PubMed:22158414, PubMed:20176268). The antigen binding site is formed by the variable domain of one heavy chain, together with that of its associated light chain. Thus, each immunoglobulin has two antigen binding sites with remarkable affinity for a particular antigen. The variable domains are assembled by a process called V-(D)-J rearrangement and can then be subjected to somatic hypermutations which, after exposure to antigen and selection, allow affinity maturation for a particular antigen (PubMed:17576170, PubMed:20176268). IgD is the major antigen receptor isotype on the surface of most peripheral B-cells, where it is coexpressed with IgM. The membrane-bound IgD (mIgD) induces the phosphorylation of CD79A and CD79B by the Src family of protein tyrosine kinases. Soluble IgD (sIgD) concentration in serum below those of IgG, IgA, and IgM but much higher than that of IgE. IgM and IgD molecules present on B cells have identical V regions and a (updated: Oct. 10, 2018)

Protein identification was indicated in the following studies:

  1. D'Alessandro and co-workers. (2017) Red blood cell proteomics update: is there more to discover? Blood Transfus. 15(2), 182-187.

Methods

The following articles were analysed to gather the proteome content of erythrocytes.

The gene or protein list provided in the studies were processed using the ID mapping API of Uniprot in September 2018. The number of proteins identified and mapped without ambiguity in these studies is indicated below.
Only Swiss-Prot entries (reviewed) were considered for protein evidence assignation.

PublicationIdentification 1Uniprot mapping 2Not mapped /
Obsolete
TrEMBLSwiss-Prot
Goodman (2013)2289 (gene list)227853205992269
Lange (2014)123412347281224
Hegedus (2015)2638262202352387
Wilson (2016)165815281702911068
d'Alessandro (2017)18261817201815
Bryk (2017)20902060101081942
Chu (2018)18531804553621387

1 as available in the article and/or in supplementary material
2 uniprot mapping returns all protein isoforms as one entry

The compilation of older studies can be retrieved from the Red Blood Cell Collection database.

The data and differentiation stages presented below come from the proteomic study and analysis performed by our partners of the GReX consortium, more details are available in their published work.

No sequence conservation computed yet.

This protein is annotated as membranous in Gene Ontology, is annotated as membranous in UniProt.


Interpro domains
Total structural coverage: 100%
Model score: 100
No model available.

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No binding partner found

The reference OMIM entry for this protein is 147170

Immunoglobulin: heavy delta chain; ighd

This locus determines the heavy chain of IgD. No idiotypic variation is known. See 147220. The majority of normal B lymphocytes carry two classes of membrane immunoglobulins, IgM and IgD. Wabl et al. (1980) found that in the mouse both IgM and IgD were expressed by a hybrid hamster-mouse subclone that contained only one mouse chromosome 12. Kirsch (1982) has evidence of two IgD heavy chain constant region genes. Brubacher et al. (1989) defined a region around the IGHD gene that has a recombination frequency approximately 50 times higher than expected--a hotspot for recombination. Benger and Cox (1989) found that although there is a high degree of association between most genes of the IGH region, there is a lack of association between the C-delta and the C-gamma-3 (147120) genes. They interpreted this as a possible indication of a hotspot for recombination. By family linkage studies, Benger et al. (1991) demonstrated that there is an unusually high level of recombination between IGHD and IGHG3 (147120), i.e., 3.2%, even though the 2 genes are only 60 kb apart. Ohta and Flajnik (2006) noted that IgD, which has been found in some mammals but not in birds, remains a mysterious molecule and a long-standing bane to immunology students. They identified the frog IgD heavy chain gene, which is located immediately 3-prime of the IgM gene. Frog IgD was expressed predominantly as a transmembrane receptor on splenic IgM-positive cells. Ohta and Flajnik (2006) concluded that IgD is as ancient as IgM. ... More on the omim web site

Subscribe to this protein entry history

Oct. 20, 2018: Protein entry updated
Automatic update: OMIM entry 147170 was added.

Oct. 19, 2018: Additional information
Initial protein addition to the database. This entry was referenced in Bryk and co-workers. (2017).