Regulation of Na(+)-coupled glucose transport in LLC-PK1 cells. Message stabilization induced by cyclic AMP elevation is accompanied by binding of a M(r) = 48,000 protein to a uridine-rich domain in the 3'-untranslated region.
Regulation of Na(+)-coupled glucose transport in LLC-PK1 cells. Message stabilization induced by cyclic AMP elevation is accompanied by binding of a M(r) = 48,000 protein to a uridine-rich domain in the 3'-untranslated region.
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LLC-PK1 细胞中 Na( ) 偶联葡萄糖转运的调节。
DOI：
10.1074/jbc.270.41.23996
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Lever,JE
中科院分区：
文献类型：
--
作者：
Peng,H;Lever,JE
在探索环amp诱导的Na+/葡萄糖共转运蛋白mRNA （SGLT1异构体）稳定伴随猪肾细胞系lc - pk1细胞分化的分子基础中，我们发现了一个48 kda的细胞质蛋白因子，称为SG-URBP，它特异性地结合了SGLT1信息3 ' -未翻译区域内的120个核苷酸序列。该区域内有一个46个核苷酸的富尿苷元素，对于特异性结合是必要的，而3 ' -未翻译区域的存在对于环AMP的信息稳定是必要的。在环AMP升高和蛋白激酶A激活后，sgg - urbp的结合活性上调，而在体外蛋白去磷酸化则与结合活性的丧失有关。SG-URBP结合活性的增加与SGLT1信息半衰期的增加相关，提示存在因果关系。
In an exploration of the molecular basis of cyclic AMP-induced stabilization of Na+/glucose cotransporter mRNA (SGLT1 isoform) accompanying cell differentiation in the pig kidney cell line LLC-PK1, we have identified a 48-kDa cytoplasmic protein factor, designated SG-URBP, which specifically binds a 120-nucleotide sequence within the 3′-untranslated region of the SGLT1 message. A 46-nucleotide uridine-rich element within this region appears necessary for specific binding, and the presence of the 3′-untranslated region is necessary for message stabilization by cyclic AMP. The binding activity of SG-URBP is up-regulated after cyclic AMP elevation and protein kinase A activation, whereas protein dephosphorylation eitherin vivoorin vitrois associated with loss of binding activity. The increase in SG-URBP binding activity correlates with an increase in the half-life of the SGLT1 message, suggesting a cause and effect relationship.