The Dictyostelium discoideum GPHR Ortholog Is an Endoplasmic Reticulum and Golgi Protein with Roles during Development
The Dictyostelium discoideum GPHR Ortholog Is an Endoplasmic Reticulum and Golgi Protein with Roles during Development
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DOI：
10.1128/ec.00208-14
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发表时间：
2015-01-01
期刊：
影响因子：
--
通讯作者：
Riyahi, Tanja Y.
中科院分区：
文献类型：
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作者：
Deckstein, Jaqueline;van Appeldorn, Jennifer;Riyahi, Tanja Y.
Dictyosteophilus discoideum GPHR（Golgi pH regulator）/Gpr 89是存在于内质网（ER）和高尔基体上的发育调节的跨膜蛋白。转录水平在生长期间较低，在发育期间变化，在聚集和后期发育阶段达到高水平。拟南芥的直系同源物被描述为存在于质膜上的脱落酸的G蛋白偶联受体（GPCR），而哺乳动物的直系同源物是高尔基体相关的阴离子通道，其功能是高尔基体pH调节剂。探讨其在D.在discoideum中，我们产生了缺乏GPHR的菌株。该突变体具有与AX 2亲本菌株不同的生长特性，在发育后期表现出变化，并形成形状异常的小蛞蝓和子实体。对发育特异性标记的分析显示，它们的表达受到干扰。内质网和高尔基体的分布在免疫荧光水平上没有改变。同样，它们的功能似乎没有受损，因为膜蛋白被适当加工和糖基化。此外，外部pH值的变化被感知的ER，如pH敏感的ER探针所示，在野生型。
Dictyostelium discoideum GPHR (Golgi pH regulator)/Gpr89 is a developmentally regulated transmembrane protein present on the endoplasmic reticulum (ER) and the Golgi apparatus. Transcript levels are low during growth and vary during development, reaching high levels during the aggregation and late developmental stages. The Arabidopsis ortholog was described as a G protein-coupled receptor (GPCR) for abscisic acid present at the plasma membrane, whereas the mammalian ortholog is a Golgi apparatus-associated anion channel functioning as a Golgi apparatus pH regulator. To probe its role in D. discoideum, we generated a strain lacking GPHR. The mutant had different growth characteristics than the AX2 parent strain, exhibited changes during late development, and formed abnormally shaped small slugs and fruiting bodies. An analysis of development-specific markers revealed that their expression was disturbed. The distributions of the endoplasmic reticulum and the Golgi apparatus were unaltered at the immunofluorescence level. Likewise, their functions did not appear to be impaired, since membrane proteins were properly processed and glycosylated. Also, changes in the external pH were sensed by the ER, as indicated by a pH-sensitive ER probe, as in the wild type.