Low-density lipoprotein receptor messenger RNA modified with MS2 aptamer stem-loops (MS2-Ldlr mRNA)

The MS2 aptamer stem-loop RNA on Ldlr mRNA is an engineered genetic construct used primarily in molecular biology and experimental gene therapy to modulate or track the Low-density lipoprotein receptor (LDLR). The MS2 system consists of specific RNA stem-loop sequences derived from the MS2 bacteriophage that are recognized with high affinity and specificity by the MS2 coat protein (MCP). By incorporating these loops into the Ldlr mRNA, researchers can recruit MCP-fused functional domains—such as fluorescent proteins for visualization or stabilizers and translational enhancers for therapeutic purposes. This approach is particularly relevant in the context of treating familial hypercholesterolemia, where increasing the expression of LDLR is critical for clearing LDL cholesterol from the blood. In advanced synthetic biology applications, this target is used within CRISPR-mediated activation systems to scaffold multiple activation domains, thereby significantly boosting the expression of the Ldlr gene to compensate for genetic deficiencies. While primarily a research tool, it represents a sophisticated target for RNA-based therapeutic strategies aiming to restore lipid homeostasis.

Other names

MS2-tagged Ldlr mRNAMS2-Ldlr transcriptMS2 stem-loop modified Low-density lipoprotein receptor mRNA

The MS2 aptamer stem-loops act as high-affinity binding sites for the MS2 coat protein (MCP). When inserted into the 3' untranslated region (UTR) or 5' UTR of Ldlr mRNA, these loops allow for the recruitment of MCP-fused effector proteins that can enhance mRNA stability, increase translation efficiency, or facilitate live-cell imaging of the transcript. In therapeutic contexts such as CRISPR activation (CRISPRa), MS2 loops on guide RNAs or target transcripts are used to recruit transcriptional activators to upregulate the endogenous production of the LDL receptor protein.