Format

Send to

Choose Destination
J Biol Chem. 2014 Dec 19;289(51):35530-41. doi: 10.1074/jbc.M114.597112. Epub 2014 Nov 3.

A conserved three-nucleotide core motif defines Musashi RNA binding specificity.

Author information

1
From the Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605.
2
From the Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605 Sean.Ryder@umassmed.edu.

Abstract

Musashi (MSI) family proteins control cell proliferation and differentiation in many biological systems. They are overexpressed in tumors of several origins, and their expression level correlates with poor prognosis. MSI proteins control gene expression by binding RNA and regulating its translation. They contain two RNA recognition motif (RRM) domains, which recognize a defined sequence element. The relative contribution of each nucleotide to the binding affinity and specificity is unknown. We analyzed the binding specificity of three MSI family RRM domains using a quantitative fluorescence anisotropy assay. We found that the core element driving recognition is the sequence UAG. Nucleotides outside of this motif have a limited contribution to binding free energy. For mouse MSI1, recognition is determined by the first of the two RRM domains. The second RRM adds affinity but does not contribute to binding specificity. In contrast, the recognition element for Drosophila MSI is more extensive than the mouse homolog, suggesting functional divergence. The short nature of the binding determinant suggests that protein-RNA affinity alone is insufficient to drive target selection by MSI family proteins.

KEYWORDS:

Binding Specificity; Cell Proliferation; Fluorescence Anisotropy; RNA; RNA Recognition; RNA-Protein Interaction; RNA-binding Protein; RRM

PMID:
25368328
PMCID:
PMC4271237
DOI:
10.1074/jbc.M114.597112
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center