LAB-1 antagonizes the Aurora B kinase in C. elegans.
Genes Dev
; 22(20): 2869-85, 2008 Oct 15.
Article
em En
| MEDLINE
| ID: mdl-18923084
ABSTRACT
The Shugoshin/Aurora circuitry that controls the timely release of cohesins from sister chromatids in meiosis and mitosis is widely conserved among eukaryotes, although little is known about its function in organisms whose chromosomes lack a localized centromere. Here we show that Caenorhabditis elegans chromosomes rely on an alternative mechanism to protect meiotic cohesin that is shugoshin-independent and instead involves the activity of a new chromosome-associated protein named LAB-1 (Long Arm of the Bivalent). LAB-1 preserves meiotic sister chromatid cohesion by restricting the localization of the C. elegans Aurora B kinase, AIR-2, to the interface between homologs via the activity of the PP1/Glc7 phosphatase GSP-2. The localization of LAB-1 to chromosomes of dividing embryos and the suppression of mitotic-specific defects in air-2 mutant embryos with reduced LAB-1 activity support a global role of LAB-1 in antagonizing AIR-2 in both meiosis and mitosis. Although the localization of a GFP fusion and the analysis of mutants and RNAi-mediated knockdowns downplay a role for the C. elegans shugoshin protein in cohesin protection, shugoshin nevertheless helps to ensure the high fidelity of chromosome segregation at metaphase I. We propose that, in C. elegans, a LAB-1-mediated mechanism evolved to offset the challenges of providing protection against separase activity throughout a larger chromosome area.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas Cromossômicas não Histona
/
Proteínas Serina-Treonina Quinases
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Regulação da Expressão Gênica no Desenvolvimento
/
Proteínas de Caenorhabditis elegans
Idioma:
En
Revista:
Genes Dev
Ano de publicação:
2008
Tipo de documento:
Article