RRC ID 4220
Author de Carvalho CE, Zaaijer S, Smolikov S, Gu Y, Schumacher JM, Colaiácovo MP.
Title LAB-1 antagonizes the Aurora B kinase in C. elegans.
Journal Genes Dev.
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.
Volume 22(20)
Pages 2869-85
Published 2008-10-15
DOI 10.1101/gad.1691208
PII 22/20/2869
PMID 18923084
PMC PMC2569883
MeSH Adenosine Triphosphatases / metabolism Amino Acid Sequence Animals Aurora Kinase B Aurora Kinases Caenorhabditis elegans Caenorhabditis elegans Proteins / antagonists & inhibitors Caenorhabditis elegans Proteins / genetics Caenorhabditis elegans Proteins / metabolism* Cell Cycle Proteins / metabolism Chromatids / genetics Chromatids / metabolism Chromosomal Proteins, Non-Histone / antagonists & inhibitors Chromosomal Proteins, Non-Histone / genetics Chromosomal Proteins, Non-Histone / metabolism* Chromosome Segregation DNA-Binding Proteins / metabolism Embryo, Nonmammalian / cytology Embryo, Nonmammalian / metabolism Fluorescent Antibody Technique Gene Expression Regulation, Developmental* Immunoglobulin G / immunology Meiosis / physiology Meiotic Prophase I / physiology Mitosis / physiology Molecular Sequence Data Multiprotein Complexes / metabolism Protein-Serine-Threonine Kinases / antagonists & inhibitors* Protein-Serine-Threonine Kinases / genetics Protein-Serine-Threonine Kinases / metabolism RNA, Helminth / genetics RNA, Helminth / metabolism RNA, Messenger / genetics RNA, Messenger / metabolism RNA, Small Interfering / pharmacology Reverse Transcriptase Polymerase Chain Reaction Sequence Homology, Amino Acid Sister Chromatid Exchange
IF 9.462
Times Cited 41
C.elegans tm1791 tm2443 tm2344 tm301 tm3002