BACKGROUND: The Bruno-like or CELF proteins, such as mammalian CUGBP1 and Etr-3, Xenopus EDEN-BP, and Drosophila Bruno (Bru), are regulators of gene expression at the post-transcriptional level, and contain three RNA-recognition motifs (RRMs). It has been shown that mammalian CUGBP1 and Etr-3 regulate alternative splicing of cardiac troponin T pre-mRNA via binding to CUG-triplet repeats. RESULTS: Using in vitro selection and UV-crosslinking experiments, we found that zebrafish Bruno-like proteins bound to repeat elements of uridine and purine (termed UREs). It is known that non-muscle (NM) and smooth muscle (SM) exons of the rat alpha-actinin gene are used in a mutually exclusive manner. Transfection experiments in mammalian cells showed that zebrafish Brul and Etr-3 induced the muscle-specific splicing of rat alpha-actinin pre-mRNA via binding to the URE at the branch point upstream of the NM exon. In contrast, zebrafish Etr-1 promoted skipping of both the NM and SM exons in a manner which was not dependent on URE-binding. CONCLUSIONS: Our results showed that Bruno-like proteins bind to UREs and regulate the alternative splicing of alpha-actinin pre-mRNA. Members of the Bruno family play multiple roles in splicing regulation.
BACKGROUND: The Bruno-like or CELF proteins, such as mammalianCUGBP1 and Etr-3, XenopusEDEN-BP, and DrosophilaBruno (Bru), are regulators of gene expression at the post-transcriptional level, and contain three RNA-recognition motifs (RRMs). It has been shown that mammalianCUGBP1 and Etr-3 regulate alternative splicing of cardiac troponin T pre-mRNA via binding to CUG-triplet repeats. RESULTS: Using in vitro selection and UV-crosslinking experiments, we found that zebrafishBruno-like proteins bound to repeat elements of uridine and purine (termed UREs). It is known that non-muscle (NM) and smooth muscle (SM) exons of the ratalpha-actinin gene are used in a mutually exclusive manner. Transfection experiments in mammalian cells showed that zebrafishBrul and Etr-3 induced the muscle-specific splicing of ratalpha-actinin pre-mRNA via binding to the URE at the branch point upstream of the NM exon. In contrast, zebrafishEtr-1 promoted skipping of both the NM and SM exons in a manner which was not dependent on URE-binding. CONCLUSIONS: Our results showed that Bruno-like proteins bind to UREs and regulate the alternative splicing of alpha-actinin pre-mRNA. Members of the Bruno family play multiple roles in splicing regulation.
Authors: Anna Jasinska; Gracjan Michlewski; Mateusz de Mezer; Krzysztof Sobczak; Piotr Kozlowski; Marek Napierala; Wlodzimierz J Krzyzosiak Journal: Nucleic Acids Res Date: 2003-10-01 Impact factor: 16.971