DLX4-Positive Cortical Promoter for Specific Gene Expression
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Solution Overview
Problem
There is a need for new sequences that can efficiently express recombinant genes in mammalian cells with high expression levels and cell-type specificity.
Innovation Solution
A synthetic promoter sequence that drives gene expression specifically in a particular DLX4-positive cells population in layer 2/3 of the mouse cortex, ensuring high expression levels and cell-type specificity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If viral promoters (CMV, SV40, RSV) are used to drive heterologous gene expression, then strong expression levels are achieved, but cell-type specificity is lost
Solution Approach 1:
The patent applies local quality by designing a promoter with specific modular elements (core promoter, proximal promoter, distal enhancer) that can be independently optimized. The distal enhancer contains DLX4-binding sites that provide local cell-type specificity, while the core promoter maintains strong transcriptional activity, achieving both high expression and specificity simultaneously
Solution Approach 2:
The patent creates a composite promoter structure by combining multiple functional elements: a strong core promoter (e.g., CMV or SV40 minimal promoter) with cell-type specific distal enhancer elements containing DLX4-binding sites. This composite design integrates the high expression capability of viral promoters with the cell-type specificity of endogenous regulatory elements
2Adaptability or versatility
If endogenous promoters are used for transgene expression, then cell-type specificity is achieved, but expression strength is reduced
Solution Approach 1:
The patent merges endogenous regulatory elements (distal enhancer with DLX4-binding sites) with strong viral core promoters to create a hybrid promoter. This combination preserves the cell-type specificity of endogenous elements while gaining the high expression strength of viral promoters, resolving the trade-off between specificity and expression level
3Adaptability or versatility
If complex eukaryotic promoter elements are included, then cell-type specificity and regulation are improved, but promoter sequence length and complexity increase
Solution Approach 1:
The patent segments the promoter into distinct functional modules: a compact core promoter region (minimal length for strong activity), a proximal promoter region, and a distal enhancer region containing specific transcription factor binding sites. This segmentation allows each element to be optimized independently, achieving high specificity without excessive overall length
Data Source
AI summary
The present invention provides an isolated nucleic acid molecule comprising, or consisting of, the nucleic acid sequence of SEQ ID NO:1, or of a nucleic acid sequence of at least 500 bp having at least 80% identity to said sequence of SEQ ID NO:1, wherein said isolated nucleic acid molecule leads to the specific expression in layer 2/3 of mouse cortex of an exogenous gene in a particular population of DLX4-positive cells when a nucleic acid sequence coding for said exogenous gene is operatively linked to said isolated nucleic acid molecule, said particular population of DLX4-positive cells being characterized in that it also expresses VTN, ABCC9 and CLDN5.