Identification of Caenorhabditis elegans K02H8.1 (CeMBL), a functional ortholog of mammalian MBNL proteins
✍ Scribed by Noboru Sasagawa; Eriko Ohno; Yoshihiro Kino; Yuichiro Watanabe; Shoichi Ishiura
- Publisher
- John Wiley and Sons
- Year
- 2009
- Tongue
- English
- Weight
- 355 KB
- Volume
- 87
- Category
- Article
- ISSN
- 0360-4012
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✦ Synopsis
Abstract
The genome of the nematode Caenorhabditis elegans possesses an orthologous sequence to the Drosophila muscleblind (mbl) and mammalian muscleblind‐like genes (__MBNL__s). This ortholog, K02H8.1, which has a high degree of homology (about 50%) to human __MBNL__s, encodes two zinc finger domains, as does the sequence of the Drosophila mbl gene. This distinguishes it from human __MBNL__s, which encode four zinc finger domains. In this study, we cloned six major isoforms of K02H8.1 using cDNA generated from C. elegans total RNA. All six of the cloned isoforms had an SL1 leader sequence at the 5′‐position. Interestingly, one of the isoforms lacked a zinc finger domain‐encoding sequence. To understand better the function of K02H8.1, we performed yeast three‐hybrid experiments to characterize the binding of K02H8.1 to bait RNAs. K02H8.1 exhibited strong binding affinity for CUG and CCUG repeats, and the binding affinity was very similar to that of MBNLs. In addition, promoter analysis was performed using promoter‐green fluorescent protein (GFP) fusion constructs. The expression of GFP driven by the K02H8.1 promoter was absent in muscle; however, significant GFP expression was detected in the neurons around the pharynx. © 2008 Wiley‐Liss, Inc.