Two GC-rich boxes in huC promoter play distinct roles in controlling its neuronal specific expression in zebrafish embryos.
HuC, a vertebrate ortholog of Drosophila elav gene, encodes an RNA binding protein and is involved in early neurogenesis. Zebrafish huC is expressed in distinct neurons, including Rohon-Beard (RB) sensory neurons, interneurons and motoneurons, during primary neurogenesis, and in all neurons later during secondary neurogenesis. In this study, we identify two GC-rich box elements, proximal GC (p-GC) box from -172 to -149 and distal GC (d-GC) box from -218 to -208, in zebrafish huC promoter. Using transgenic approach, we demonstrate that deletion of the p-GC box from the promoter results in loss of expression of the reporter GFP in neurons while deletion of the d-GC box leads to GFP expression only in dorsal RB sensory neurons. These results suggest that the p-GC box alone confers transcriptional activity of huC promoter in primary RB neurons and the d-GC is required for huC transcription in the full spectrum of spinal cord neurons. Further studies are needed to identify specific Sp1-like transcription factors that bind to these GC boxes and activate huC transcription.
Zhao
Chengtian
C
Protein Science Laboratory of Ministry of Education of China, Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing 100084, China.
He
Xinjun
X
Tian
Chenxi
C
Meng
Anming
A
D000818:Animals; D030801:Animals, Genetically Modified; D051959:ELAV Proteins / Q000235:genetics* / Q000378:metabolism*; D000067778:ELAV-Like Protein 3; D004625:Embryo, Nonmammalian / Q000196:embryology / Q000378:metabolism; D020862:GC Rich Sequence / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental; D017930:Genes, Reporter / Q000235:genetics; D008969:Molecular Sequence Data; D009474:Neurons / Q000378:metabolism*; D009928:Organ Specificity; D011401:Promoter Regions, Genetic / Q000235:genetics*; D016329:Sp1 Transcription Factor / Q000378:metabolism; D015027:Zebrafish / Q000196:embryology* / Q000235:genetics / Q000378:metabolism*; D029961:Zebrafish Proteins / Q000235:genetics* / Q000378:metabolism*
D051959:ELAV Proteins; D000067778:ELAV-Like Protein 3; D016329:Sp1 Transcription Factor; D029961:Zebrafish Proteins; C088635:elavl3 protein, zebrafish