E3 Ligase for CENP-A (Part 1)

Abstract

CENP-A is a centromere-specific histone H3 variant that is required to ensure kinetochore assembly for proper chromosome segregation and its function is highly conserved among different species including budding yeast, Saccharomyces cerevisiae. The budding yeast Saccharomyces cerevisiae has genetically defined point centromeres, unlike other eukaryotes. Although, most eukaryotic centromeres are maintained epigenetically, currently only budding yeast S. cerevisiae centromeres are known to be genetically specified by DNA sequence, The small size and sequence specificity of the budding yeast centromere has made yeast a powerful organism for its study in many aspects. Many post-translational modifications (PTMs) of CENP-A and their functions have been recently reported, and studies with budding yeast are providing insights into the role of CENP-A/Cse4 PTMs in kinetochore structure and function. Multiple functions are controlled especially by ubiquitylation and sumoylation by E3 ligases that control CENP-A protein has initially emerged in the budding yeast as an important regulatory mechanism. Here we focus on what is known about the budding yeast E3 ligases for CENP-A/Cse4 ubiquitylation and sumoylation and their biological functions and significance.