Ser68 phosphoregulation is essential for CENP-A deposition, centromere function and viability in mice

Area of Science:

• Cell Biology
• Epigenetics
• Molecular Biology

Background:

• Centromere identity relies on CENP-A (centromere protein A), a histone H3 variant.
• CENP-A deposition at centromeres is a cell-cycle-dependent process.
• Previous research suggested CENP-A Ser68 phosphorylation regulates CENP-A incorporation, but this was recently contested.

Purpose of the Study:

• To investigate the role of CENP-A Ser68 phosphorylation in CENP-A deposition and cell viability.
• To resolve conflicting reports regarding the necessity of Ser68 phosphoregulation for CENP-A loading.

Main Methods:

• Generating mice and cell lines with endogenous CENP-A Ser68 substituted with Gln68 or Glu68.
• Assessing CENP-A deposition at centromeres.
• Evaluating cell viability and organismal lethality.

Main Results:

• Substitution of CENP-A Ser68 with Gln68 or Glu68 significantly impaired CENP-A deposition.
• Mutations in CENP-A Ser68 led to reduced cell viability.
• Mice with corresponding CENP-A mutations were lethal, indicating essential function.

Conclusions:

• Dynamic phosphorylation of CENP-A Ser68 is essential for cell-cycle-dependent CENP-A deposition.
• This phosphorylation event is critical for maintaining cell viability and organismal development.
• The findings reaffirm the importance of Ser68 phosphoregulation in centromere biology.