Human TRIM71 and its nematode homologue are targets of let-7 microRNA and its zebrafish orthologue is essential for development.
Animal microRNAs (miRNAs) are short RNAs that function as posttranscriptional regulators of gene expression by binding to the target mRNAs. Noting that some miRNAs are highly conserved in evolution, we explored the possibility of evolutionary conservation of their targets. We identified human orthologues of experimentally verified let-7 miRNA target genes in Caenorhabditis elegans and used the luciferase reporter system to examine whether these human genes are still the targets of let-7 miRNA. We found that in some cases, the miRNA-target relationship has indeed been conserved in human. Interestingly, human TRIM71, an orthologue of C. elegans let-7-target lin-41 gene, can be repressed by hsa-let-7a and hsa-let-7c. This repression was abolished when both predicted let-7 target sites of TRIM71 were mutated. Moreover, the zebrafish lin-41 orthologue was also repressed by let-7 to a similar degree as was TRIM71. When the expression of zebrafish lin-41 orthologue was silenced by microinjection of RNA interference or morpholino into zebrafish zygotes, retarded embryonic development was observed, providing direct evidence for an essential role of lin-41 in zebrafish development. Taken together, our results suggest that the regulation of TRIM71 expression by let-7 has been evolutionarily conserved and that TRIM71 likely plays an important role in development.
Lin
You-Chin
YC
Genomics Research Center, Academia Sinica, Taipei, Taiwan.
Hsieh
Li-Ching
LC
Kuo
Ming-Wei
MW
Yu
John
J
Kuo
Huan-Hsien
HH
Lo
Wan-Lin
WL
Lin
Ruey-Jen
RJ
Yu
Alice L
AL
Li
Wen-Hsiung
WH
D000818:Animals; D001483:Base Sequence; D017173:Caenorhabditis elegans / Q000235:genetics*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics; D045744:Cell Line, Tumor; D004625:Embryo, Nonmammalian / Q000196:embryology / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D035683:MicroRNAs / Q000235:genetics*; D034622:RNA Interference; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics; D000070584:Tripartite Motif Proteins; D044767:Ubiquitin-Protein Ligases / Q000235:genetics; D015027:Zebrafish / Q000196:embryology / Q000235:genetics*
D029742:Caenorhabditis elegans Proteins; C410586:LIN-41 protein, C elegans; D035683:MicroRNAs; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D000070584:Tripartite Motif Proteins; C474488:let-7 microRNA, C elegans; D008156:Luciferases; C584142:TRIM71 protein, human; D044767:Ubiquitin-Protein Ligases