title: Arabidopsis thaliana WAPL is essential for the prophase removal of cohesin during meiosis.
abstract: Sister chromatid cohesion, which is mediated by the cohesin complex, is essential for the proper segregation of chromosomes in mitosis and meiosis. The establishment of stable sister chromatid cohesion occurs during DNA replication and involves acetylation of the complex by the acetyltransferase CTF7. In higher eukaryotes, the majority of cohesin complexes are removed from chromosomes during prophase. Studies in fly and human have shown that this process involves the WAPL mediated opening of the cohesin ring at the junction between the SMC3 ATPase domain and the N-terminal domain of cohesin's α-kleisin subunit. We report here the isolation and detailed characterization of WAPL in Arabidopsis thaliana. We show that Arabidopsis contains two WAPL genes, which share overlapping functions. Plants in which both WAPL genes contain T-DNA insertions show relatively normal growth and development but exhibit a significant reduction in male and female fertility. The removal of cohesin from chromosomes during meiotic prophase is blocked in Atwapl mutants resulting in chromosome bridges, broken chromosomes and uneven chromosome segregation. In contrast, while subtle mitotic alterations are observed in some somatic cells, cohesin complexes appear to be removed normally. Finally, we show that mutations in AtWAPL suppress the lethality associated with inactivation of AtCTF7. Taken together our results demonstrate that WAPL plays a critical role in meiosis and raises the possibility that mechanisms involved in the prophase removal of cohesin may vary between mitosis and meiosis in plants.
authors.affiliation: Department of Chemistry and Biochemistry, Miami University, Oxford, Ohio, United States of America.
authors.forename: Kuntal
authors.initials: K
authors.lastname: De
authors.affiliation: Department of Chemistry and Biochemistry, Miami University, Oxford, Ohio, United States of America.
authors.forename: Lauren
authors.initials: L
authors.lastname: Sterle
authors.affiliation: Department of Chemistry and Biochemistry, Miami University, Oxford, Ohio, United States of America.
authors.forename: Laura
authors.initials: L
authors.lastname: Krueger
authors.affiliation: Department of Chemistry and Biochemistry, Miami University, Oxford, Ohio, United States of America.
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Yang
authors.affiliation: Department of Chemistry and Biochemistry, Miami University, Oxford, Ohio, United States of America.
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Makaroff
mesh_terms: D000123:Acetyltransferases / Q000235:genetics* / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D002453:Cell Cycle; D018797:Cell Cycle Proteins / Q000235:genetics* / Q000378:metabolism*; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism*; D002875:Chromosomes / Q000378:metabolism; D004261:DNA Replication / Q000235:genetics; D006801:Humans; D008540:Meiosis / Q000235:genetics; D008938:Mitosis / Q000235:genetics; D011418:Prophase / Q000235:genetics*; D012854:Sister Chromatid Exchange / Q000235:genetics; D000097722:Cohesins
chemical_list: D000123:Acetyltransferases; D029681:Arabidopsis Proteins; D018797:Cell Cycle Proteins; D002868:Chromosomal Proteins, Non-Histone; D000097722:Cohesins; C000595120:WAPL protein, Arabidopsis; C583922:CTF7 protein, Arabidopsis