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MBNL1 associates with YB‐1 in cytoplasmic stress granules
Author(s) -
Onishi Hayato,
Kino Yoshihiro,
Morita Tomoko,
Futai Eugene,
Sasagawa Noboru,
Ishiura Shoichi
Publication year - 2008
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/jnr.21655
Subject(s) - stress granule , rna binding protein , dead box , rna splicing , rna helicase a , biology , rna , cytoplasm , microbiology and biotechnology , helicase , genetics , gene , messenger rna , translation (biology)
The muscleblind‐like (MBNL) protein family is thought to be involved in the molecular mechanism of myotonic dystrophy (DM). Although it has been shown to have splicing activity, a broader function in cellular RNA metabolism has been implicated. In this study, we attempted to find the binding proteins of MBNL1 in order to elucidate its physiological function. First, we performed a GST pull‐down assay using GST‐MBNL1‐6xHis as bait. Several proteins were identified, including YB‐1, a multifunctional DNA/RNA‐binding protein, and DDX1, a DEAD box RNA helicase. MBNL1 formed an RNP complex with YB‐1 and DDX1 in binding assays. YB‐1 also showed a weak but significant effect on α‐actinin splice site selection. Interestingly, in response to stress, MBNL1 moved to cytoplasmic stress granules, where it colocalized with YB‐1, which was previously reported to be a component of stress granules. We found that DDX1 also colocalized with MBNL1 at stress granules. These results provide new insight into the dynamics of MBNL1 in response to stress, and they suggest a role for MBNL1 in mRNA metabolism in the cytoplasm. © 2008 Wiley‐Liss, Inc.