Abstract
Much of the patterning of early C. elegans embryos involves a series of Notch interactions that occur in rapid succession and have distinct outcomes; however, none of the targets for these interactions have been identified. We show that the REF-1 family of bHLH transcription factors is a major target of Notch signaling in all these interactions and that most examples of Notch-mediated transcriptional repression can be attributed to REF-1 activities. The REF-1 family is expressed and has similar functions in both Notch-dependent and Notch-independent pathways, and this dual mode of deployment is used repeatedly to pattern the embryo. REF-1 proteins are unusual in that they contain two different bHLH domains and lack the distinguishing characteristics of Hairy/Enhancer of Split (HES) bHLH proteins that are Notch targets in other systems. Our results show that the highly divergent REF-1 proteins are nonetheless HES-like bHLH effectors of Notch signaling.
Publication types
-
Comparative Study
-
Research Support, N.I.H., Extramural
-
Research Support, Non-U.S. Gov't
-
Research Support, U.S. Gov't, P.H.S.
MeSH terms
-
Age Factors
-
Animals
-
Animals, Genetically Modified
-
Basic Helix-Loop-Helix Transcription Factors
-
Caenorhabditis elegans
-
Caenorhabditis elegans Proteins / genetics
-
Caenorhabditis elegans Proteins / metabolism*
-
DNA-Binding Proteins / metabolism*
-
Drosophila
-
Drosophila Proteins
-
Embryo, Nonmammalian
-
Fluorescent Antibody Technique / methods
-
Gene Expression Regulation, Developmental / physiology*
-
Membrane Proteins / physiology*
-
Models, Biological
-
Molecular Sequence Data
-
Morphogenesis / physiology
-
Mutagenesis / physiology
-
RNA, Double-Stranded / metabolism
-
Receptors, Notch
-
Sequence Alignment
-
Signal Transduction / physiology*
-
Transcription Factors / metabolism*
Substances
-
Basic Helix-Loop-Helix Transcription Factors
-
Caenorhabditis elegans Proteins
-
DNA-Binding Proteins
-
Drosophila Proteins
-
Membrane Proteins
-
N protein, Drosophila
-
RNA, Double-Stranded
-
Receptors, Notch
-
Transcription Factors
-
ref-1 protein, C elegans