RNA-binding protein Musashi homolog 1 (MSI1)

RNA-binding protein Musashi homolog 1 (MSI1), commonly known as Musashi-1, is a highly conserved RNA-binding protein characterized by two RNA recognition motifs (RRMs) in its N-terminal region, serving a crucial role in the regulation of post-transcriptional gene expression. MSI1 acts primarily as a marker of neural and epithelial stem and progenitor cells, where it governs the balance between self-renewal and differentiation. By selectively binding single-stranded RNA motifs (notably those containing UAG core sequences), MSI1 represses translation of key target mRNAs, such as components of the Notch signaling pathway, contributing to the regulation of proliferation, differentiation, and cell fate decisions. Overexpression of MSI1 is linked to multiple cancer types (gliomas, melanomas, endometrial carcinoma) and neurodevelopmental disorders (e.g., microcephaly), and it may also play a role in susceptibility to Zika virus infection due to direct protein-viral RNA interactions. Fatty acids such as oleic acid can inhibit MSI1's RNA binding allosterically. MSI1 is a valued biomarker for stem cell populations and a putative drug target in oncology and regenerative medicine research.

Other names

Musashi-1Musashi1musashi1MSI1musashi RNA binding protein 1RNA-binding protein Musashi homolog 1

Allosteric inhibition of RNA binding domain by ω–9 monounsaturated fatty acids (e.g., oleic acid). Translational repression via binding to specific RNA motifs (RU_nAGU consensus, especially UAG). Blockade of ribosome binding to target mRNA by direct interaction.