Abstract
The Caenorhabditis elegans anteroposterior axis is established in response to fertilization by sperm. Here we present evidence that RhoA, the guanine nucleotide-exchange factor ECT-2, and the Rho guanosine triphosphatase-activating protein CYK-4 modulate myosin light-chain activity to create a gradient of actomyosin, which establishes the anterior domain. CYK-4 is enriched within sperm, and paternally donated CYK-4 is required for polarity. These data suggest that CYK-4 provides a molecular link between fertilization and polarity establishment in the one-cell embryo. Orthologs of CYK-4 are expressed in sperm of other species, which suggests that this cue may be evolutionarily conserved.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, Non-U.S. Gov't
MeSH terms
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Actomyosin / physiology
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Animals
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Caenorhabditis elegans / embryology*
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Caenorhabditis elegans / physiology
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Caenorhabditis elegans Proteins / analysis
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Caenorhabditis elegans Proteins / genetics
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Caenorhabditis elegans Proteins / physiology*
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Cell Polarity*
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Cytokinesis
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Cytoskeleton / physiology
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Embryo, Nonmammalian / chemistry
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Embryo, Nonmammalian / cytology*
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Embryo, Nonmammalian / physiology
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Female
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Fertilization
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GTPase-Activating Proteins / analysis
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GTPase-Activating Proteins / genetics
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GTPase-Activating Proteins / physiology*
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Guanine Nucleotide Exchange Factors / analysis
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Guanine Nucleotide Exchange Factors / genetics
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Guanine Nucleotide Exchange Factors / physiology
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Male
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Myosin Light Chains / metabolism
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Myosin Type II / analysis
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Organelles / chemistry
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Proteins / analysis
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RNA Interference
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Spermatozoa / chemistry
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Spermatozoa / ultrastructure
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rhoA GTP-Binding Protein / genetics
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rhoA GTP-Binding Protein / physiology
Substances
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CYK-4 protein, C elegans
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Caenorhabditis elegans Proteins
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Ect-2 protein, C elegans
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GTPase-Activating Proteins
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Guanine Nucleotide Exchange Factors
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Myosin Light Chains
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Proteins
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par-6 protein, C elegans
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Actomyosin
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Myosin Type II
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rhoA GTP-Binding Protein