Functional analysis of synaptotagmin gene regulatory regions in two distantly related ascidian species.
We have studied the structure and function of a promoter region of the Halocynthia synaptotagmin (Hr-Syt) gene, which is abundantly expressed in neuronal cells. Our previous analysis suggested that the expression of Hr-Syt is regulated by at least one epidermal and two neuronal regulatory regions. In this study, the regulatory regions of Hr-Syt promoter were further characterized by using two species of ascidians, Halocynthia roretzi and Ciona intestinalis embryos. A putative GATA transcription factor binding site in the epidermal regulatory region has ectodermal enhancer activity in the Halocynthia embryo. Neuronal expression of Hr-Syt was regulated by multiple redundant enhancer regions. Among these enhancer regions, a 200-bp (-2900/-2700) region drove the reporter expression in neurons in both species of ascidian. Although the synaptotagmin promoter sequences did not show overall similarity between Hr-Syt and Ciona synaptotagmin (Ci-Syt), 5'-upsteream two short sequences of Ci-Syt have similarity to the -2766/-2732 region of the Hr-Syt promoter. The homeodomain binding sites in this region are required for the neuronal enhancer activity. These results suggest that GATA and homeodomain transcription factors regulate the expression of synaptotagmin.
Matsumoto
Jun
J
Molecular Neurobiology Group, Neuroscience Research Institute, AIST Tsukuba Central 6-12, Tsukuba, Ibaraki 305-8566, Japan. jun.matsumoto@mcgill.ca
Katsuyama
You
Y
Ohtsuka
Yukio
Y
Lemaire
Patrick
P
Okamura
Yasushi
Y
D000818:Animals; D030801:Animals, Genetically Modified; D001483:Base Sequence; D004625:Embryo, Nonmammalian; D017353:Gene Deletion; D018507:Gene Expression Regulation, Developmental; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D008954:Models, Biological; D016297:Mutagenesis, Site-Directed; D009928:Organ Specificity / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics / Q000502:physiology*; D013045:Species Specificity; D050857:Synaptotagmins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D014018:Tissue Distribution; D014561:Urochordata / Q000235:genetics*
D050857:Synaptotagmins; D049452:Green Fluorescent Proteins