Mammalian SGO2 appears at the inner centromere domain and redistributes depending on tension across centromeres during meiosis II and mitosis.
Shugoshin (SGO) is a family of proteins that protect centromeric cohesin complexes from release during mitotic prophase and from degradation during meiosis I. Two mammalian SGO paralogues - SGO1 and SGO2 - have been identified, but their distribution and function during mammalian meiosis have not been reported. Here, we analysed the expression of SGO2 during male mouse meiosis and mitosis. During meiosis I, SGO2 accumulates at centromeres during diplotene, and colocalizes differentially with the cohesin subunits RAD21 and REC8 at metaphase I centromeres. However, SGO2 and RAD21 change their relative distributions during telophase I when sister-kinetochore association is lost. During meiosis II, SGO2 shows a striking tension-dependent redistribution within centromeres throughout chromosome congression during prometaphase II, as it does during mitosis. We propose a model by which the redistribution of SGO2 would unmask cohesive centromere proteins, which would be then released or cleaved by separase, to trigger chromatid segregation to opposite poles.
Gómez
Rocío
R
Unidad de Biología Celular, Departamento de Biología, Universidad Autónoma de Madrid, Madrid, Spain.
Valdeolmillos
Ana
A
Parra
María Teresa
MT
Viera
Alberto
A
Carreiro
Candelas
C
Roncal
Fernando
F
Rufas
Julio S
JS
Barbero
José L
JL
Suja
José A
JA
D000818:Animals; D018797:Cell Cycle Proteins / Q000378:metabolism*; D002503:Centromere / Q000378:metabolism*; D004268:DNA-Binding Proteins; D005455:Fluorescent Antibody Technique; D008297:Male; D008540:Meiosis / Q000502:physiology*; D051379:Mice; D009687:Nuclear Proteins / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism; D013090:Spermatocytes / Q000502:physiology*
D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D010750:Phosphoproteins; C465862:Rad21 protein, mouse; C465863:Rec8 protein, mouse