ジャーナル: Cell Res / 年: 2020 タイトル: Structural insights into secretory immunoglobulin A and its interaction with a pneumococcal adhesin. 著者: Yuxin Wang / Guopeng Wang / Yaxin Li / Qinyu Zhu / Hao Shen / Ning Gao / Junyu Xiao / 要旨: Secretory Immunoglobulin A (SIgA) is the most abundant antibody at the mucosal surface. It possesses two additional subunits besides IgA: the joining chain (J-chain) and secretory component (SC). SC ...Secretory Immunoglobulin A (SIgA) is the most abundant antibody at the mucosal surface. It possesses two additional subunits besides IgA: the joining chain (J-chain) and secretory component (SC). SC is the ectodomain of the polymeric immunoglobulin receptor (pIgR), which functions to transport IgA to the mucosa. How the J-chain and pIgR/SC facilitate the assembly and secretion of SIgA remains incompletely understood. Furthermore, during the infection of Streptococcus pneumoniae, the pneumococcal adhesin SpsA hijacks pIgR/SC and SIgA to gain entry to human cells and evade host defense. How SpsA targets pIgR/SC and SIgA also remains elusive. Here we report a cryo-electron microscopy structure of the Fc region of IgA1 (Fcα) in complex with the J-chain and SC (Fcα-J-SC), which reveals the organization principle of SIgA. We also present a structure of Fcα-J-SC complexed with SpsA, which uncovers the specific interactions between SpsA and human pIgR/SC. These results advance the molecular understanding of SIgA and shed light on S. pneumoniae pathogenesis.
Interleukin-2,Immunoglobulinheavyconstantalpha1 / IL-2 / T-cell growth factor / TCGF / Ig alpha-1 chain C region / Ig alpha-1 chain C region BUR / Ig ...IL-2 / T-cell growth factor / TCGF / Ig alpha-1 chain C region / Ig alpha-1 chain C region BUR / Ig alpha-1 chain C region TRO
分子量: 31445.693 Da / 分子数: 4 / 由来タイプ: 組換発現 / 由来: (組換発現) Homo sapiens (ヒト) / 遺伝子: IL2, IGHA1 / 発現宿主: Homo sapiens (ヒト) / 参照: UniProt: P60568, UniProt: P01876
#2: タンパク質
ImmunoglobulinJchain / Joining chain of multimeric IgA and IgM
分子量: 19225.762 Da / 分子数: 1 / 由来タイプ: 組換発現 / 由来: (組換発現) Homo sapiens (ヒト) / 遺伝子: JCHAIN, IGCJ, IGJ / 発現宿主: Homo sapiens (ヒト) / 参照: UniProt: P01591
#3: タンパク質
Polymericimmunoglobulinreceptor / Poly-Ig receptor / Hepatocellular carcinoma-associated protein TB6
分子量: 63306.336 Da / 分子数: 1 / 由来タイプ: 組換発現 / 由来: (組換発現) Homo sapiens (ヒト) / 遺伝子: PIGR / 発現宿主: Homo sapiens (ヒト) / 参照: UniProt: P01833
Has protein modification
Y
-
実験情報
-
実験
実験
手法: 電子顕微鏡法
EM実験
試料の集合状態: PARTICLE / 3次元再構成法: 単粒子再構成法
-
試料調製
構成要素
名称: Ternary complex of IgA-Fc with the J chain and pIgR/SC タイプ: COMPLEX / Entity ID: all / 由来: RECOMBINANT
由来(天然)
生物種: Homo sapiens (ヒト)
由来(組換発現)
生物種: Homo sapiens (ヒト)
緩衝液
pH: 7.4
試料
濃度: 0.3 mg/ml / 包埋: NO / シャドウイング: NO / 染色: NO / 凍結: YES