A novel sea urchin nuclear receptor encoded by alternatively spliced maternal RNAs.
A novel sea urchin nuclear receptor encoded by alternatively spliced maternal RNAs.
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一种由选择性剪接母体 RNA 编码的新型海胆核受体。
DOI：
10.1006/dbio.1996.0171
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
Flytzanis,CN
中科院分区：
文献类型：
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作者：
Kontrogianni-Konstantopoulos,A;Vlahou,A;Vu,D;Flytzanis,CN
以人COUP-TF Ⅰ cDNA为探针，从海胆（Strongylocentrotus purpuratus）基因组文库中筛选到一个新的类固醇-甲状腺-视黄酸受体超家族成员SpSHR 2（S.类固醇激素受体2）。分离的基因组克隆的序列分析显示，该孤儿受体的DNA结合结构域与人TR 2受体最同源。以该海胆基因组片段为探针，aS.从紫胚cDNA文库中筛选出两个不同但同源的cDNA克隆。这两个cDNA编码与SpSHR 2基因相同的DNA结合结构域，并携带几乎相同的3′-非翻译序列。然而，其中一个克隆缺失了约1100 nt的整个区域，该区域包括推定的配体结合结构域。基因组DNA杂交结果表明，SpSHR 2在S.紫色基因组单个初级转录物剪接过程中的外显子跳跃似乎是不同大小mRNA的原因。RNA印迹杂交结果表明，SpSHR 2转录本作为母体RNA储存在卵细胞中，在囊胚期以后检测不到。海胆肌动蛋白CyIIIb基因的侧翼区。在体内标记卵裂期胚胎合成的蛋白质，然后免疫沉淀使用特异性抗体的SpSHR 2蛋白揭示了母体SpSHR 2 mRNA在早期胚胎发育期间被翻译。
Screening of a genomic library from the sea urchinStrongylocentrotus purpuratuswith a human COUP-TF I cDNA probe revealed the presence of a novel gene member of the steroid–thyroid–retinoic acid receptor superfamily, which was named SpSHR2 (S. purpuratusSteroid Hormone Receptor 2). Sequence analysis of the isolated genomic clone revealed that the DNA binding domain of this orphan receptor is most homologous to the human TR2 receptor. Using this sea urchin genomic fragment as probe, aS. purpuratusembryonic cDNA library was screened and two distinct but homologous cDNA clones were isolated. The two cDNAs encode the same DNA binding domain as the SpSHR2 gene and carry an almost identical 3′-untranslated sequence. One of the clones, however, is missing an entire region of about 1100 nt which includes the putative ligand binding domain. Genomic DNA hybridization suggests that SpSHR2 is a single-copy gene in theS. purpuratusgenome. Exon skipping during splicing of a single primary transcript appears to be the reason for the differently sized mRNAs. RNA blot hybridization results suggest that SpSHR2 transcripts are stored as maternal RNA in the egg and are not detected beyond the blastula stage.In vitrotranscription and translation of the full-length cDNA produced a polypeptide which specifically binds to the hormone response element in the 5′-flanking region of the sea urchin actin CyIIIb gene.In vivolabeling of proteins synthesized by cleavage stage embryos followed by immune precipitation of the SpSHR2 protein using specific antibodies reveals that the maternal SpSHR2 mRNA is being translated during early embryonic development.