CBX8 Interacts with Chromatin PTEN and is Involved in Regulating Mitotic Progression

Overview

Journal Cell Prolif

Date 2021 Sep 30

PMID 34592789

Citations 4

Authors

Byeong Hyeok Choi

Tania Marlyn Colon

Eunji Lee

Ziyue Kou

Wei Dai

Affiliations

Soon will be listed here.

Abstract

Objectives: Besides its role in regulating phosphatidylinositol-3 kinase (PI3K) signalling in the cytosol, PTEN also has a nuclear function. In this study, we attempted to understand the mechanism of chromatin PTEN in suppressing chromosomal instability during cell division.

Materials And Methods: Immunocoprecipitation, ectopic expression, and deletional analyses were used to identify the physical interaction between Chromobox Homolog protein 8 (CBX8) and PTEN, as well as the functional domain(s) of PTEN mediating the interaction. Cell synchronization followed by immunoblotting was employed to study cell cycle regulation of CBX8 and the functional interaction between chromatin PTEN and CBX8. Small interfering RNAs (siRNAs) were used to study the role of PTEN and CBX8 in modulating histone epigenetic markers during the cell cycle.

Results: Polycomb group (PcG) proteins including CBXs function to repress gene expression in a wide range of organisms including mammals. We recently showed that PTEN interacted with CBX8, a component of Polycomb Repressing Complex 1 (PRC1), and that CBX8 co-localized with PTEN in the nucleus. CBX8 levels were high, coinciding with its phosphorylation in mitosis. Phosphorylation of CBX8 was associated with monoubiquitinated PTEN and phosphorylated-BubR1 on chromatin. Moreover, CBX8 played an important role in cell proliferation and mitotic progression. Significantly, downregulation of either PTEN or CBX8 induced H3K27Me3 epigenetic marker in mitotic cells.

Conclusion: CBX8 is a new component that physically interacts with chromatin PTEN, playing an important role in regulating mitotic progression.

Citing Articles

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Meng Q, Li L, Wang L Front Oncol. 2022; 12:881262.

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CBX8 interacts with chromatin PTEN and is involved in regulating mitotic progression.

Choi B, Colon T, Lee E, Kou Z, Dai W Cell Prolif. 2021; 54(11):e13110.

PMID: 34592789 PMC: 8560621. DOI: 10.1111/cpr.13110.

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