THE TOBACCO HOMOLOG OF MAMMALIAN CALRETICULIN IS PRESENT IN PROTEIN COMPLEXES IN-VIVO
THE TOBACCO HOMOLOG OF MAMMALIAN CALRETICULIN IS PRESENT IN PROTEIN COMPLEXES IN-VIVO
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DOI：
10.1105/tpc.7.4.391
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发表时间：
1995-04-01
期刊：
影响因子：
11.6
通讯作者：
PALVA, ET
中科院分区：
文献类型：
--
作者：
DENECKE, J;CARLSSON, LE;PALVA, ET
网状浆蛋白（RPLs）是一组存在于内质网（ER）管腔内的可溶性蛋白，对其保留的蛋白质分选信号的分析揭示了哺乳动物和植物内质网保留信号在结构上的相似性。我们提出的证据表明，相应的表位在一个庞大的可溶性内质网驻留蛋白家族中是保守的。RPL60和RPL90是该家族的两个丰富成员，其微序列与哺乳动物钙网蛋白和内质酶具有高度的相似性。RPL60/calreticulin与管腔结合蛋白（BiP）结合并粘附。在核膜和内质网以及与纺锤体和膜质体相关的有丝分裂细胞中均检测到这两种蛋白。来自体内标记细胞的蛋白质免疫沉淀表明，RPL60/钙网蛋白以应激和atp依赖的方式与其他多肽相关。在赤霉素处理的大麦糊粉细胞中，RPL60/calreticulin转录物水平在分泌器官增殖和水解酶分泌开始的过程中迅速增加。这种诱导谱与特征明确的内质网伴侣蛋白BiP和内质酶相同。然而，不同应激条件下的表达模式以及组织特异性表达模式表明，这些基因受到不同的调节，可能不一致。
The analysis of protein sorting signals responsible for the retention of reticuloplasmins (RPLs), a group of soluble proteins that reside in the lumen of the endoplasmic reticulum (ER), has revealed a structural similarity between mammalian and plant ER retention signals. We present evidence that the corresponding epitope is conserved in a vast family of soluble ER resident proteins. Microsequences of RPL60 and RPL90, two abundant members of this family, show high sequence similarity with mammalian calreticulin and endoplasmin. RPL60/calreticulin cofractionates and costains with the lumenal binding protein (BiP). Both protei ns were detected in the nuclear envelope and the ER, and in mitotic cells in association with the spindle apparatus and the phragmoplast. Immunoprecipitation of proteins from in vivo-labeled cells demonstrated that RPL60/calreticulin is associated with other polypeptides in a stress- and ATP-dependent fashion. RPL60/calreticulin transcript levels increased rapidly in abundance during the proliferation of the secretory apparatus and the onset of hydrolase secretion in gibberellic acid-treated barley aleurone cells. This induction profile is identical to that of the well-characterized ER chaperones BiP and endoplasmin. However, expression patterns in response to different stress conditions as well as tissue-specific expression patterns indicate that these genes are differentially regulated and may not act in concert.