Dataset Information

Ascl1 and Neurog2 form novel complexes and regulate Delta-like3 (Dll3) expression in the neural tube.

ABSTRACT: Delta-like 3 (Dll3) is a Delta family member expressed broadly in the developing nervous system as neural progenitor cells initiate differentiation. A proximal promoter sequence for Dll3 is conserved across multiple species and is sufficient to direct GFP expression in a Dll3-like pattern in the neural tube of transgenic mice. This promoter contains multiple E-boxes, the consensus binding site for bHLH factors. Dll3 expression and the activity of the Dll3-promoter in the dorsal neural tube depends on the basic helix-loop-helix (bHLH) transcription factors Ascl1 (Mash1) and Neurog2 (Ngn2). Mutations in each E-box identified in the Dll3-promoter allowed distinct enhancer or repressor properties to be assigned to each site individually or in combination. In addition, each E-box has distinct characteristics relative to binding of bHLH factors Ascl1, Neurog1, and Neurog2. Surprisingly, novel Ascl1 containing DNA binding complexes are identified that interact with specific E-box sites within the Dll3-promoter in vitro. These complexes include Ascl1/Ascl1 homodimers and Ascl1/Neurog2 heterodimers, complexes that in some cases require additional undefined factors for efficient DNA binding. Thus, a complex interplay of E-box binding proteins spatially and temporally regulate Dll3 levels during neural tube development.

SUBMITTER: Henke RM

PROVIDER: S-EPMC2698949 | biostudies-literature | 2009 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Ascl1 and Neurog2 form novel complexes and regulate Delta-like3 (Dll3) expression in the neural tube.

Henke R Michael RM Meredith David M DM Borromeo Mark D MD Savage Trisha K TK Johnson Jane E JE

Developmental biology 20090114 2

Delta-like 3 (Dll3) is a Delta family member expressed broadly in the developing nervous system as neural progenitor cells initiate differentiation. A proximal promoter sequence for Dll3 is conserved across multiple species and is sufficient to direct GFP expression in a Dll3-like pattern in the neural tube of transgenic mice. This promoter contains multiple E-boxes, the consensus binding site for bHLH factors. Dll3 expression and the activity of the Dll3-promoter in the dorsal neural tube depen ...[more]

PMID: 19389376

Similar Datasets

Project description:The proneural NEUROG2 is essential for neuronal commitment, cell cycle exit and neuronal differentiation. Characterizing genes networks regulated downstream of NEUROG2 is therefore of prime importance. To identify NEUROG2 early response genes, we combined gain of function in the neural tube with a global detection of modified transcripts using microarrays. We included in our study a mutant form of NEUROG2 (NEUROG2AQ) that cannot bind DNA and cannot trigger neurogenesis. Using this approach, we identified 942 genes modified at the onset of NEUROG2 activation. The global analysis of functions regulated by NEUROG2 allowed unmasking its rapid impact on cell cycle control. We found that NEUROG2 specifically represses a subset of cyclins acting at the G1 and S phases of the cell cycle, thereby impeding S phase re-entry. This repression occurs before modification of p27kip1, indicating that the decision to leave the cell cycle precedes the activation of this Cyclin-dependant Kinase Inhibitor. Moreover, NEUROG2 down-regulates only one of the D-type cyclins, cyclinD1, and maintaining cyclinD1 blocks the ability of the proneural to trigger cell cycle exit, without altering its capacity to trigger neuronal differentiation. The fact that NEUROG2 represses a subset but not all cell cycle regulators indicates that cell cycle exit is not an indirect consequence of neuronal differentiation but is precisely controlled by NEUROG2. Altogether our findings indicate that NEUROG2, by specifically repressing G1 and S cyclins, allows committed neuronal precursors to perform their last mitosis but blocks their re-entry in the cell cycle, thus favouring cell cycle exit. Stage HH10-11 embryos (11 to 15 somites) were electroporated with a control vector (pGIG-GFP), a NEUROG2-expressing vector (pCIGNEUROG2-GFP), or a NEUROG2AQ-expressing vector (pCIGNEUROG2AQ-GFP). For each biological replicate, neural tubes from 20 embryos were pooled for GFP+ cells collection. GFP+ cells were collected 6h later using FACS sorting (Epics Altra HSS cell sorter, Toulouse Rio platform) and processed for RNA probe preparation and hybridization on Affymetrix microarrays. For each experimental condition, four biological replicates were processed.

Dataset Information

Ascl1 and Neurog2 form novel complexes and regulate Delta-like3 (Dll3) expression in the neural tube.

Publications

Ascl1 and Neurog2 form novel complexes and regulate Delta-like3 (Dll3) expression in the neural tube.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets