TY - JOUR TI - Conformational change within the extracellular domain of B cell receptor in B cell activation upon antigen binding AU - Shen, Zhixun AU - Liu, Sichen AU - Li, Xinxin AU - Wan, Zhengpeng AU - Mao, Youxiang AU - Chen, Chunlai AU - Liu, Wanli A2 - Chakraborty, Arup K A2 - Dustin, Michael L A2 - Tolar, Pavel A2 - Alarcon, Balbino VL - 8 PY - 2019 DA - 2019/07/10 SP - e42271 C1 - eLife 2019;8:e42271 DO - 10.7554/eLife.42271 UR - https://doi.org/10.7554/eLife.42271 AB - B lymphocytes use B cell receptors (BCRs) to recognize antigens. It is still not clear how BCR transduces antigen-specific physical signals upon binding across cell membrane for the conversion to chemical signals, triggering downstream signaling cascades. It is hypothesized that through a series of conformational changes within BCR, antigen engagement in the extracellular domain of BCR is transduced to its intracellular domain. By combining site-specific labeling methodology and FRET-based assay, we monitored conformational changes in the extracellular domains within BCR upon antigen engagement. Conformational changes within heavy chain of membrane-bound immunoglobulin (mIg), as well as conformational changes in the spatial relationship between mIg and Igβ were observed. These conformational changes were correlated with the strength of BCR activation and were distinct in IgM- and IgG-BCR. These findings provide molecular mechanisms to explain the fundamental aspects of BCR activation and a framework to investigate ligand-induced molecular events in immune receptors. KW - B cell receptor KW - BCR activation KW - conformational change KW - FRET JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -