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Title | Structure of the human secretory immunoglobulin M core. |
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Journal, issue, pages | Structure, Vol. 29, Issue 6, Page 564-571.e3, Year 2021 |
Publish date | Jun 3, 2021 |
![]() | Nikit Kumar / Christopher P Arthur / Claudio Ciferri / Marissa L Matsumoto / ![]() |
PubMed Abstract | Immunoglobulins (Ig) A and M are the only human antibodies that form oligomers and undergo transcytosis to mucosal secretions via the polymeric Ig receptor (pIgR). When complexed with the J-chain (JC) ...Immunoglobulins (Ig) A and M are the only human antibodies that form oligomers and undergo transcytosis to mucosal secretions via the polymeric Ig receptor (pIgR). When complexed with the J-chain (JC) and the secretory component (SC) of pIgR, secretory IgA and IgM (sIgA and sIgM) play critical roles in host-pathogen defense. Recently, we determined the structure of sIgA-Fc which elucidated the mechanism of polymeric IgA assembly and revealed an extensive binding interface between IgA-Fc, JC, and SC. Despite low sequence identity shared with IgA-Fc, IgM-Fc also undergoes JC-mediated assembly and binds pIgR. Here, we report the structure of sIgM-Fc and carryout a systematic comparison to sIgA-Fc. Our structural analysis reveals a remarkably conserved mechanism of JC-templated oligomerization and SC recognition of both IgM and IgA through a highly conserved network of interactions. These studies reveal the structurally conserved features of sIgM and sIgA required for function in mucosal immunity. |
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Methods | EM (single particle) |
Resolution | 3.3 Å |
Structure data | EMDB-22591, PDB-7k0c: |
Source |
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![]() | IMMUNE SYSTEM / Immunoglobulin M |