TableEdit

Wang, J, Beauchemin, M and Bertrand, R (2011) Bcl-xL phosphorylation at Ser49 by polo kinase 3 during cell cycle progression and checkpoints. Cell. Signal. 23:2030-8

Functional analysis of a Bcl-xL phosphorylation mutant series has revealed that cells expressing Bcl-xL(Ser49Ala) mutant are less stable at G2 checkpoint after DNA damage and enter cytokinesis more slowly after microtubule poisoning, than cells expressing wild-type Bcl-xL. These effects of Bcl-xL(Ser49Ala) mutant seem to be separable from Bcl-xL function in apoptosis. Bcl-xL(Ser49) phosphorylation is cell cycle-dependent. In synchronized cells, phospho-Bcl-xL(Ser49) appears during the S phase and G2, whereas it disappears rapidly in early mitosis during prometaphase, metaphase and early anaphase, and re-appears during telophase and cytokinesis. During DNA damage-induced G2 arrest, an important pool of phospho-Bcl-xL(Ser49) accumulates in centrosomes which act as essential decision centers for progression from G2 to mitosis. During telophase/cytokinesis, phospho-Bcl-xL(Ser49) is found with dynein motor protein. In a series of in vitro kinase assays, specific small interfering RNA and pharmacological inhibition experiments, polo kinase 3 (PLK3) was implicated in Bcl-xL(Ser49) phosphorylation. These data indicate that, during G2 checkpoint, phospho-Bcl-xL(Ser49) is another downstream target of PLK3, acting to stabilize G2 arrest. Bcl-xL phosphorylation at Ser49 also correlates with essential PLK3 activity and function, enabling cytokinesis and mitotic exit.

PubMed PMC3708862 Online version:10.1016/j.cellsig.2011.07.017

Cell Cycle Proteins/metabolism; Cell Line; Cell Nucleus Division; Cyclin B1/metabolism; Cytokinesis; DNA Damage; G2 Phase Cell Cycle Checkpoints; Histones/metabolism; Humans; Phosphorylation; Protein Transport; Protein-Serine-Threonine Kinases/metabolism; Proto-Oncogene Proteins/metabolism; Serine/metabolism; bcl-X Protein/metabolism