Related Experiment Video
Updated: Jun 19, 2026

Measuring Endoplasmic Reticulum Stress and Unfolded Protein Response in HIV-1 Infected T-Cells and Analyzing its Role in HIV-1 Replication
Published on: June 14, 2024
53BP1 represses mitotic catastrophe in syncytia elicited by the HIV-1 envelope
J-L Perfettini1, R Nardacci, C Séror
1INSERM U, Villejuif, France.
Abstract:
p53 binding protein-1 (53BP1) participates in checkpoint signaling during the DNA damage response (DDR) and during mitosis. In this study we report that 53BP1 aggregates in nuclear foci within syncytia elicited by the human immunodeficiency virus (HIV)-1 envelope. 53BP1 aggregation occurs as a consequence of nuclear fusion (karyogamy (KG)). It colocalizes partially with the promyelomonocytic leukemia protein (PML), and the ataxia telangiectasia mutated kinase (ATM), the two components of the DDR that mediate apoptosis induced by the HIV-1 envelope. ATM-dependent phosphorylation of 53BP1 on serines 25 and 1778 (53BP1S25P and 53BP1S1778P) occurs at these DNA damage foci. 53BP1S25P was also detected in syncytia present in the lymph nodes or frontal brain sections from HIV-1-infected carriers, as well as in peripheral blood mononucleated cells from HIV-1-infected individuals, correlating with viral load. Knockdown of 53BP1 caused HIV-1 envelope-induced syncytia to enter abnormal mitoses, leading to their selective destruction through mitochondrion-dependent and caspase-dependent pathways. In conclusion, depletion of 53BP1 triggers the demise of HIV-1-elicited syncytia through mitotic catastrophe.
More Related Videos
Related Concept Videos
Inhibitors of Virion Maturation and Assembly
Separation of Sister Chromatids
At the onset of anaphase, separase, a proteolytic enzyme, is...
Negative Regulator Molecules
Replicative Cell Senescence
Anaphase Promoting Complex
The Spindle Assembly Checkpoint
Many proteins function together to control the spindle assembly checkpoint. Mutations affecting these proteins may allow cells to proceed into anaphase prematurely, resulting in the...

