Cloning, characterization and tissue expression of rat SULT2B1a and SULT2B1b steroid/sterol sulfotransferase isoforms: divergence of the rat SULT2B1 gene structure from orthologous human and mouse genes.
Cloning, characterization and tissue expression of rat SULT2B1a and SULT2B1b steroid/sterol sulfotransferase isoforms: divergence of the rat SULT2B1 gene structure from orthologous human and mouse genes.
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大鼠 SULT2B1a 和 SULT2B1b 类固醇/甾醇磺基转移酶亚型的克隆、表征和组织表达：大鼠 SULT2B1 基因结构与直系同源人类和小鼠基因的差异。
DOI：
10.1016/j.gene.2005.09.009
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发表时间：
2006
期刊：
影响因子：
3.5
通讯作者：
Strott,CharlesA
中科院分区：
文献类型：
--
作者：
Kohjitani,Atsushi;Fuda,Hirotoshi;Hanyu,Osamu;Strott,CharlesA
克隆大鼠SULT 2B 1类固醇/甾醇磺基转移酶亚型的cDNA，并过表达、纯化和表征编码的蛋白质。大鼠SULT 2B 1a亚型强烈地磺化异烯醇酮，但很少利用胆固醇作为底物，而SULT 2B 1b亚型比异烯醇酮更有效地磺化胆固醇;另一方面，两种亚型都不能显著地磺化脱氢表雄酮。Real-time PCR结果显示，SULT 2B 1a仅在脑和睾丸中表达，而SULT 2B 1b主要在皮肤、肠和肾脏中表达。SULT 2B 1基因在类固醇/固醇磺基转移酶基因中是独特的，因为它编码两种亚型，作为选择性外显子I的结果。有趣的是，尽管人类和小鼠的SULT 2B 1基因结构是相同的，但大鼠的SULT 2B 1基因结构却不同。与人和小鼠SULT 2B 1基因相似，大鼠SULT 2B 1基因由一个选择性外显子I组成;然而，由于外显子重排，外显子IA和IB的基因位置在大鼠基因中发生逆转。在人和小鼠SULT 2B 1基因中，外显子IA位于外显子IB的下游，而在大鼠SULT 2B 1基因中，外显子IA位于外显子IB的上游。此外，与人类和小鼠SULT 2B 1基因的情况不同，其中由于外显子IA的一部分与外显子IB融合以完成SULT 2B 1b mRNA，因此需要差异剪接，而大鼠基因不需要该步骤。
cDNAs for rat SULT2B1 steroid/sterol sulfotransferase isoforms were cloned, and the encoded proteins overexpressed, purified and characterized. The rat SULT2B1a isoform avidly sulfonates pregnenolone but poorly utilizes cholesterol as a substrate, whereas cholesterol is more efficiently sulfonated than pregnenolone by the SULT2B1b isoform; on the other hand, neither isoform sulfonates dehydroepiandrosterone to any significant degree. Real-time PCR revealed that SULT2B1a was only expressed in brain and testis, whereas SULT2B1b was mainly expressed in skin, intestine and kidney. The SULT2B1 gene is unique among steroid/sterol sulfotransferase genes in that it encodes for two isoforms as a result of an alternative exon I. Interestingly, whereas the orthologous human and mouse SULT2B1 gene structures are identical, the rat SULT2B1 gene structure diverges. Similar to human and mouse SULT2B1 genes the rat SULT2B1 gene consists of an alternative exon I; however, as a result of exonic rearrangement, the genic locations of exons IA and IB are reversed in the rat gene. Where exon IA is located downstream of exon IB in the human and mouse SULT2B1 genes, in the rat SULT2B1 gene exon IA is located upstream of exon IB. Furthermore, unlike the case with human and mouse SULT2B1 genes where differential splicing is necessitated since a portion of exon IA is fused with exon IB to complete the SULT2B1b mRNA, this step is not required with the rat gene.