MEC-8 regulates alternative splicing of unc-52 transcripts in C. elegans hypodermal cells.
Previous work has shown that C. elegans MEC-8 is a putative RNA-binding protein that promotes specific alternative splices of unc-52 transcripts. unc-52 encodes homologs of mammalian perlecan that are located extracellularly between muscle and hypodermis and are essential for muscle development in both embryos and larvae. We show that MEC-8 is a nuclear protein found in hypodermis at most stages of development and not in most late embryonic or larval body-wall muscle. We have also found that overexpression of MEC-8 in hypodermis but not muscle can suppress certain unc-52 mutant phenotypes. These are unexpected results because it has been proposed that UNC-52 is produced exclusively by muscle. We have constructed various tissue-specific unc-52 minigenes fused to a gene for green fluorescent protein that have allowed us to monitor tissue-specific mec-8-dependent alternative splicing; we show that mec-8 must be expressed in the same cell type as the unc-52 minigene in order to regulate its expression, supporting the view that MEC-8 acts directly on unc-52 transcripts and that UNC-52 must be synthesized primarily by the hypodermis. Indeed, our analysis of unc-52 genetic mosaics has shown that the focus of unc-52 action is not in body-wall muscle but most likely is in hypodermis.
Spike
Caroline A
CA
Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis 55455, USA.
Davies
Andrew G
AG
Shaw
Jocelyn E
JE
Herman
Robert K
RK
D017398:Alternative Splicing; D000818:Animals; D030801:Animals, Genetically Modified; D001483:Base Sequence; D017173:Caenorhabditis elegans / Q000196:embryology / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000235:genetics* / Q000378:metabolism; D018509:DNA, Helminth / Q000235:genetics; D020405:Dermis / Q000196:embryology / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D017238:Genes, Helminth; D015801:Helminth Proteins / Q000235:genetics* / Q000378:metabolism; D007814:Larva / Q000378:metabolism; D008565:Membrane Proteins; D009030:Mosaicism; D009132:Muscles / Q000196:embryology / Q000378:metabolism; D011509:Proteoglycans / Q000235:genetics* / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D014018:Tissue Distribution
D029742:Caenorhabditis elegans Proteins; D018509:DNA, Helminth; D015801:Helminth Proteins; D008565:Membrane Proteins; D011509:Proteoglycans; D016601:RNA-Binding Proteins; C099356:mec-8 protein, C elegans; C082396:unc-52 protein, C elegans