IDENTIFICATION OF A RAT C-ERBA-ALPHA- RELATED PROTEIN WHICH BINDS DEOXYRIBONUCLEIC-ACID BUT DOES NOT BIND THYROID-HORMONE
IDENTIFICATION OF A RAT C-ERBA-ALPHA- RELATED PROTEIN WHICH BINDS DEOXYRIBONUCLEIC-ACID BUT DOES NOT BIND THYROID-HORMONE
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DOI：
10.1210/mend-2-10-893
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发表时间：
1988-10-01
影响因子：
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通讯作者：
CHIN, WW
中科院分区：
文献类型：
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作者：
LAZAR, MA;HODIN, RA;CHIN, WW
先前已从多个物种和组织中分离出编码甲状腺激素结合受体蛋白的 c-erbA cDNA。我们分离出一种新型大鼠 c-erbA cDNA，r-erbA.alpha.-2，与大鼠脑 c-erbA.alpha 相同。 cDNA（我们称为 r-erbA.alpha.-1），除了 cDNA 的 3'' 末端，它编码预测氨基酸序列的改变的羧基末端区域。 r-erbA.alpha.-2 cDNA 与人睾丸 c-erbA.alpha 关系最为密切。 cDNA。该cDNA的体外蛋白质产物的表观分子量为55K，接近从核苷酸序列预测的分子量。 r-erbA.alpha.-2 蛋白结合含有来自大鼠 GH 基因的推定 T3 响应序列的 DNA 片段。然而，r-erbaA.alpha.-2蛋白产物不结合T3。从大鼠 GH3 细胞和各种大鼠组织中分离的 RNA 含有至少三个与 c-erbA.alpha 杂交的 mRNA。探针。主要的 2.6 kb mRNA 与 r-erbA.alpha.-2 特异性杂交，而 5.0 kb mRNA 与 r-erbA.alpha.-1 特异性 cDNA 探针杂交。 r-erbA.α.-1相关的5.0kb mRNA通过T3处理在GH3细胞中下调，如先前针对2.6kb mRNA所描述的。 r-erbA.alpha.-2 mRNA 在大脑中最丰富，而 r-erbA.alpha.-1 mRNA 在棕色脂肪和骨骼肌中浓度最高。 r-ebA.alpha.-1 mRNA 与 r-erbA.alpha.-2 mRNA 不同，在睾丸中检测不到。 Southern 分析表明 r-erbA.alpha.-1 和 r-erbA.alpha.-2 mRNA 来自单个基因转录本。
c-erbA cDNAs encoding thyroid hormone-binding receptor proteins have been previously isolated from several species and tissues. We have isolated a novel rat c-erbA cDNA, r-erbA.alpha.-2, identical to the rat brain c-erbA.alpha. cDNA (which we refer to as r-erbA.alpha.-1) except at the 3''-end of the cDNA, which encodes an altered carboxy-terminal region of the predicted amino acid sequence. The r-erbA.alpha.-2 cDNA is most closely related to the human testicular c-erbA.alpha. cDNA. The apparent molecular weight of the in vitro protein product of this cDNA is 55 K, close to that predicted from the nucleotide sequence. The r-erbA.alpha.-2 protein binds a DNA fragment containing a putative T3-responsive sequence from the rat GH gene. However, the r-erbaA.alpha.-2 protein product does not bind T3. RNA isolated from rat GH3 cells and various rat tissues contains at least three mRNAs hybridizing to c-erbA.alpha. probes. A predominant 2.6 kilobase mRNA hybridizes specifically to r-erbA.alpha.-2, while a 5.0 kb mRNA hybridizes to r-erbA.alpha.-1-specific cDNA probes. The r-erbA.alpha.-1-related 5.0 kb mRNA is down-regulated by T3 treatment in GH3 cells as has previously been described for the 2.6 kb mRNA. The r-erbA.alpha.-2 mRNA is most abundant in brain, whereas the r-erbA.alpha.-1 mRNA is found in highest concentration in brown fat and skeletal muscle. r-ebA.alpha.-1 mRNA, unlike r-erbA.alpha.-2 mRNA, is undetectable in testis. Southern analyses suggest that the r-erbA.alpha.-1 and r-erbA.alpha.-2 mRNAs are derived from a single gene transcript.