Functions of HP1 in preventing chromosomal instability.

Chromosomal instability (CIN), caused by errors in the segregation of chromosomes during mitosis, is a hallmark of many types of cancer. The fidelity of chromosome segregation is governed by a sophisticated cellular signaling network, one crucial orchestrator of which is Heterochromatin protein 1 (HP1). HP1 dynamically localizes to distinct sites at various stages of mitosis, where it regulates key mitotic events ranging from chromosome–microtubule attachment to sister chromatid cohesion to cytokinesis. Our evolving comprehension of HP1's multifaceted role has positioned it as a central protein in the orchestration of mitotic processes. Significance Statement: In recent years, numerous studies have demonstrated a robust correlation between Heterochromatin protein 1 (HP1) and chromosomal instability. While initially recognized as a heterochromatin protein, it is now evident that the HP1 encompasses diverse functions. These include involvement in RNA splicing, sister chromatid cohesion, chromosome segregation, telomere maintenance, DNA repair, and transcriptional regulation. Across various stages of mitosis, HP1 dynamically localizes to distinct cellular sites, where it regulates crucial mitotic processes, such as chromosome‐microtubule attachment, sister chromatid cohesion, and cytokinesis. HP1 emerges as a pivotal component within the intricate network governing the fidelity of chromosome segregation. [ABSTRACT FROM AUTHOR]