Dbf4-Dependent Kinase (DDK)-Mediated Proteolysis of CENP-A Prevents Mislocalization of CENP-A in Saccharomyces cerevisiae. Issue 6 (1st June 2020)

• Record Type: Journal Article
• Authors: Eisenstatt, Jessica R; Boeckmann, Lars; Au, Wei-Chun; Garcia, Valerie; Bursch, Levi; Ocampo, Josefina; Costanzo, Michael; Weinreich, Michael; Sclafani, Robert A; Baryshnikova, Anastasia; Myers, Chad L; Boone, Charles; Clark, David J; Baker, Richard; Basrai, Munira A
• Is Part Of: G3. Volume 10:Issue 6(2020)
• Page Start: 2057
• Page End: 2068
• Publication Date: 2020-06-01
• Subjects: Centromere -- Cse4 -- CENP-A -- DDK -- Psh1 -- Cdc7; Genetics -- Research -- Periodicals; Genomics -- Periodicals; Genetics; Genomics; Genes; Genetics -- Research; Genomics; Electronic journals; Periodical; Periodicals; Fulltext; Internet Resources; Periodicals; 572.8
• DOI: 10.1534/g3.120.401131
• Languages: English
• ISSNs: 2160-1836

Abstract

Abstract: The evolutionarily conserved centromeric histone H3 variant (Cse4 in budding yeast, CENP-A in humans) is essential for faithful chromosome segregation. Mislocalization of CENP-A to non-centromeric chromatin contributes to chromosomal instability (CIN) in yeast, fly, and human cells and CENP-A is highly expressed and mislocalized in cancers. Defining mechanisms that prevent mislocalization of CENP-A is an area of active investigation. Ubiquitin-mediated proteolysis of overexpressed Cse4 ( GALCSE4 ) by E3 ubiquitin ligases such as Psh1 prevents mislocalization of Cse4, and psh1 Δ strains display synthetic dosage lethality (SDL) with GALCSE4 . We previously performed a genome-wide screen and identified five alleles of CDC7 and DBF4 that encode the Dbf4 -dependent kinase (DDK) complex, which regulates DNA replication initiation, among the top twelve hits that displayed SDL with GALCSE4 . We determined that cdc7 -7 strains exhibit defects in ubiquitin-mediated proteolysis of Cse4 and show mislocalization of Cse4 . Mutation of MCM5 ( mcm5 -bob1 ) bypasses the requirement of Cdc7 for replication initiation and rescues replication defects in a cdc7 -7 strain. We determined that mcm5 -bob1 does not rescue the SDL and defects in proteolysis of GALCSE4 in a cdc7 -7 strain, suggesting a DNA replication-independent role for Cdc7 in Cse4 proteolysis. The SDL phenotype, defects in ubiquitin-mediated proteolysis, and the mislocalization pattern of Cse4 in a cdc7 -7 psh1 Δ strain were similar to that of cdc7 -7 and psh1 Δ strains, suggesting that Cdc7 regulates Cse4 in a pathway that overlaps with Psh1 . Our results define a DNA replication initiation-independent role of DDK as a regulator of Psh1 -mediated proteolysis of Cse4 to prevent mislocalization of Cse4 .