Recombinant Danio rerio La-related protein 7 (larp7), partial

Overview of Recombinant Danio rerio La-related Protein 7 (larp7), Partial

Recombinant Danio rerio La-related protein 7 (larp7), partial refers to a truncated or domain-specific version of the zebrafish LARP7 protein produced via recombinant expression systems. This protein is derived from the larp7 gene (also known as fa10g04, zgc:56476, or wu:fa10g04) and is part of the La-related protein family, which regulates RNA metabolism and transcription elongation .

Functional Context of LARP7 in Zebrafish

LARP7 is evolutionarily conserved and critical for maintaining 7SK small nuclear ribonucleoprotein (snRNP) stability. In zebrafish, it interacts with 7SK RNA, P-TEFb (Cdk9/cyclin T1), and HEXIM1/2 to regulate transcription elongation and alternative splicing .

Key Roles in Development and RNA Regulation

• 7SK snRNP Assembly: LARP7 binds the 3′ U-rich tail of 7SK RNA via its La motif and RNA recognition motif 1 (RRM1), stabilizing the core 7SK snRNP alongside BCDIN3 (γ-methylphosphate capping enzyme) .

• Transcription Control: Sequestration of P-TEFb by 7SK snRNP inhibits transcription elongation. LARP7 knockdown in zebrafish disrupts 7SK stability, leading to P-TEFb derepression and developmental defects (e.g., brain degeneration, axial abnormalities) .

• Alternative Splicing: 7SK snRNP regulates splicing via P-TEFb suppression. larp7 knockdown in zebrafish alters splicing patterns of genes like neogenin-1 and matrilin-3b .

Production Methods

• Host Systems: E. coli (for cost-effective, high-yield production) or eukaryotic systems (e.g., mammalian cells) for post-translational modifications .

• Purification: Affinity chromatography (e.g., His-tag or SUMO-tag systems) followed by SDS-PAGE validation .

Potential Applications

Gaps and Future Directions

While recombinant zebrafish LARP7 proteins are available, no published studies specifically address the partial construct’s functional characterization. Key areas for research include:

1. Domain-Specific Functions: Testing whether the partial LARP7 retains RNA-binding (La/RRM1) or P-TEFb interaction capabilities.

2. Zebrafish Models: Leveraging morpholino knockdown or CRISPR-Cas9 to link larp7 mutations to phenotypic outcomes .

3. Comparative Evolution: Comparing zebrafish LARP7 with human/mouse orthologs to identify conserved/unique regulatory mechanisms .