Structure and function analysis of LIN-14, a temporal regulator of postembryonic developmental events in Caenorhabditis elegans.
During postembryonic development of Caenorhabditis elegans, the heterochronic gene lin-14 controls the timing of developmental events in diverse cell types. Three alternative lin-14 transcripts are predicted to encode isoforms of a novel nuclear protein that differ in their amino-terminal domains. In this paper, we report that the alternative amino-terminal domains of LIN-14 are dispensable and that a carboxy-terminal region within exons 9 to 13 is necessary and sufficient for in vivo LIN-14 function. A transgene capable of expressing only one of the three alternative lin-14 gene products rescues a lin-14 null mutation and is developmentally regulated by lin-4. This shows that the deployment of alternative lin-14 gene products is not critical for the ability of LIN-14 to regulate downstream genes in diverse cell types or for the in vivo regulation of LIN-14 level by lin-4. The carboxy-terminal region of LIN-14 contains an unusual expanded nuclear localization domain which is essential for LIN-14 function. These results support the view that LIN-14 controls developmental timing in C. elegans by regulating gene expression in the nucleus.
Hong
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Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755, USA.
Lee
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RC
Ambros
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D000595:Amino Acid Sequence; D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics* / Q000254:growth & development; D029742:Caenorhabditis elegans Proteins; D005786:Gene Expression Regulation / Q000502:physiology*; D015801:Helminth Proteins / Q000502:physiology*; D008969:Molecular Sequence Data; D009687:Nuclear Proteins; D016415:Sequence Alignment; D014162:Transfection
D029742:Caenorhabditis elegans Proteins; D015801:Helminth Proteins; C102669:LIN-14 protein, C elegans; D009687:Nuclear Proteins