LähettiRNA

LähettiRNA, commonly translated as guide RNA, is a short RNA molecule used to direct programmable nucleases to specific DNA sequences in CRISPR systems. It serves as the sequence-specific component that recognizes target DNA, working together with a nuclease such as Cas9 or other Cas proteins to form a functional CRISPR complex. The term distinguishes the RNA guide from the nuclease itself.

Structure and function: A lähettiRNA contains a spacer region, typically around 20 nucleotides, that is complementary to the target DNA sequence. It also includes a scaffold that binds the nuclease and enables the complex to adopt the correct conformation for DNA binding and cleavage. The nuclease requires recognition of a protospacer adjacent motif (PAM) next to the target sequence to initiate binding, and the base pairing between the spacer and target directs the cleavage site.

Production and formats: LähettiRNA can be produced in vivo by transcription from DNA templates or synthesized in vitro by chemical methods. In many CRISPR applications, a single-guide RNA (sgRNA) fuses the crRNA and tracrRNA into one molecule to simplify delivery. Chemical modifications may be added to improve stability, reduce degradation, and modulate immune recognition in some contexts.

Applications and limitations: LähettiRNA is central to genome editing workflows in basic research and has potential therapeutic uses when delivered with a suitable nuclease. It enables targeted gene disruption, insertion, or regulation. Design considerations include minimizing off-target effects, ensuring the presence of an appropriate PAM, and addressing delivery challenges. Ethical, safety, and regulatory factors also guide clinical and translational uses.