Cloning and characterization of SCHIP-1, a novel protein interacting specifically with spliced isoforms and naturally occurring mutant NF2 proteins
Cloning and characterization of SCHIP-1, a novel protein interacting specifically with spliced isoforms and naturally occurring mutant NF2 proteins
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DOI：
10.1128/mcb.20.5.1699-1712.2000
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发表时间：
2000-03-01
影响因子：
5.3
通讯作者：
Thomas, G
中科院分区：
文献类型：
--
作者：
Goutebroze, L;Brault, E;Thomas, G
神经纤维瘤病2型（NF 2）蛋白，称为神经鞘蛋白或梅林，是一种肿瘤抑制因子，与NF 2相关和散发性神经鞘瘤和脑膜瘤有关。它与ezrin-radixin-moesin家族成员密切相关，涉及将膜蛋白连接到细胞骨架。神经鞘蛋白作为肿瘤抑制因子的分子机制尚不清楚。为了阐明神经鞘蛋白的功能，我们已经鉴定了一种新型卷曲螺旋蛋白SCHIP-1，它在体外和体内与神经鞘蛋白特异性结合。在其卷曲螺旋区域内，该蛋白质与人FEZ蛋白和相关的秀丽隐杆线虫基因产物E10 -76同源。瞬时转染细胞的免疫荧光染色显示SCHIP-1和神经鞘蛋白的部分共定位，在细胞质膜下。令人惊讶的是，免疫沉淀试验表明，在细胞环境中，与SCHIP-1的关联可以观察到，只有一些天然存在的突变体的雪旺氏素，或雪旺氏素剪接亚型缺乏外显子2和3，但不与雪旺氏素亚型表现出生长抑制活性。我们的观察结果表明，SCHIP-1与神经鞘蛋白的相互作用是受神经鞘蛋白的构象变化，可能是由转录后修饰，选择性剪接，或突变诱导。
The neurofibromatosis type 2 (NF2) protein, known as schwannomin or merlin, is a tumor suppressor involved in NF2-associated and sporadic schwannomas and meningiomas. It is closely related to the ezrin-radixin-moesin family members, implicated in linking membrane proteins to the cytoskeleton. The molecular mechanism allowing schwannomin to function as a tumor suppressor is unknown. In attempt to shed light on schwannomin function, we have identified a novel coiled-coil protein, SCHIP-1, that specifically associates with schwannomin in vitro and in vivo. Within its coiled-coil region, this protein is homologous to human FEZ proteins and the related Caenorhabditis elegans gene product UNC-76. Immunofluorescent staining of transiently transfected cells shows a partial colocalization of SCHIP-1 and schwannomin, beneath the cytoplasmic membrane. Surprisingly, immunoprecipitation assays reveal that in a cellular context, association with SCHIP-1 can be observed only with some naturally occurring mutants of schwannomin, or a schwannomin spliced isoform lacking exons 2 and 3, but not with the schwannomin isoform exhibiting growth-suppressive activity. Our observations suggest that SCHIP-1 interaction with schwannomin is regulated by conformational changes in schwannomin, possibly induced by posttranstational modifications, alternative splicing, or mutations.