Postmitotic G1 phase survivin drives mitogen-independent cell division of B lymphocytes.

Amit Singh, Matthew H Spitzer, Jaimy P Joy, Mary Kaileh, Xiang Qiu, Garry P Nolan, Ranjan Sen

Proceedings of the National Academy of Sciences of the United States of America 2022 May 03

filter terms:

B and T lymphocytes of the adaptive immune system undergo proliferative bursts to generate pools of antigen-specific cells for effective immunity. Here we show that in contrast to the canonical view that G1 progression signals are essential after mitosis to reenter S phase, B lymphocytes sustain several rounds of mitogen-independent cell division following the first mitosis. Such division appears to be driven by unique characteristics of the postmitotic G1 phase that has features of S and G2/M phases. Birc5 (survivin), a protein associated with chromosome segregation in G2/M, is expressed in the G1 phase of divided B cells and is necessary for mitogen-independent divisions. The partially active G1 phase and propensity for apoptosis inherited after each division may underlie rapid proliferation and cell death, which are hallmarks of B cell proliferative responses.

Citation

Amit Singh, Matthew H Spitzer, Jaimy P Joy, Mary Kaileh, Xiang Qiu, Garry P Nolan, Ranjan Sen. Postmitotic G1 phase survivin drives mitogen-independent cell division of B lymphocytes. Proceedings of the National Academy of Sciences of the United States of America. 2022 May 03;119(18):e2115567119