Myostatin pre-mRNA exonic splicing enhancer in exon 1 (MSTN ESE1) (MSTN ESE1)

The Myostatin (MSTN) pre-mRNA exonic splicing enhancer in exon 1 is a critical cis-acting regulatory RNA sequence that facilitates the correct processing and maturation of the myostatin transcript [1, 2]. Myostatin, also known as Growth Differentiation Factor 8 (GDF-8), is a member of the TGF-beta superfamily and acts as a potent negative regulator of skeletal muscle growth [1, 6]. By targeting this specific splicing enhancer with antisense oligonucleotides (ASOs), such as the experimental agent KMM001, researchers aim to inhibit the maturation of pre-mRNA by preventing the excision of the first intron [1, 3]. This intervention effectively reduces the production of functional myostatin protein, promoting muscle hypertrophy and increasing muscle strength [1, 9]. This approach is particularly promising for treating muscle-wasting disorders like Duchenne muscular dystrophy and sarcopenia, as targeting the unique sequence in exon 1 offers greater specificity and fewer off-target effects compared to inhibitors targeting the highly conserved protein domains shared with GDF11 [1, 3]. Experimental studies have shown that blocking this enhancer prevents the binding of the splicing factor SRSF5, leading to a reciprocal increase in pre-mRNA and a decrease in mature mRNA levels [1, 4]. Consequently, this target represents a novel genetic approach to muscle therapy that bypasses the limitations of traditional protein-level myostatin blockade [1, 5].

Other names

MSTN exon 1 splicing enhancerGDF-8 exon 1 ESEMyostatin exon 1 ESEMSTN ESE

Splice-switching antisense oligonucleotide (SSO) binding to the exonic splicing enhancer (ESE) in exon 1, which sterically blocks the recruitment of splicing factors (e.g., SRSF5), thereby inhibiting the excision of intron 1 and preventing the maturation of pre-mRNA into functional myostatin protein [1, 3].