Multiple domains in the Crumbs Homolog 2a (Crb2a) protein are required for regulating rod photoreceptor size.
Multiple domains in the Crumbs Homolog 2a (Crb2a) protein are required for regulating rod photoreceptor size.
复制标题
DOI：
10.1186/1471-2121-11-60
复制
发表时间：
2010-07-29
期刊：
影响因子：
--
通讯作者：
Jensen AM
中科院分区：
文献类型：
--
作者：
Hsu YC;Jensen AM
脊椎动物视网膜光感受器是形态复杂的细胞，具有两个顶端区域，即内段和外段。外节是一个修改纤毛和不断再生整个生活。脊椎动物感光细胞形态发生和外节维持的分子和细胞机制在很大程度上是未知的。Crumbs（Crb）复合物是上皮细胞和果蝇光感受器中顶膜身份和大小的关键调节剂。人类基因CRUMBS HOMOR1（CRB1）的突变与早期和严重的视力丧失有关。果蝇Crumbs和脊椎动物Crb1和Crumbs同源物2（Crb2）蛋白在结构上相似，都是单次跨膜蛋白，具有包含多个层粘连蛋白和EGF样重复的大的胞外结构域和包含FERM结合结构域和PDZ结合结构域的小的胞内结构域。为了开始理解Crb蛋白家族在脊椎动物光感受器中的作用，我们产生了稳定的转基因斑马鱼，其中杆状光感受器过表达全长Crb2a蛋白和几种其他Crb2a构建体，其被工程化以缺乏特异性结构域。我们研究了Crb2a结构的定位及其对杆形态的影响。我们发现，只有全长的Crb2a蛋白接近正常定位的Crb2a蛋白顶端的感光细胞内段中的adherens连接。几个Crb2a构建体蛋白异常定位于外节，一个构建体异常定位于细胞体。全长Crb2a的过表达大大增加了内段的大小，而其他几个结构的表达增加了外段的大小。我们的观察表明，Crb2a中的特定结构域调节其定位，从而可能调节其区域化功能。我们的研究结果还表明，在Crb2a的PDZ结合域可能会带来一个蛋白质（S）到Crb复合物，改变FERM结合域的功能。
Vertebrate retinal photoreceptors are morphologically complex cells that have two apical regions, the inner segment and the outer segment. The outer segment is a modified cilium and is continuously regenerated throughout life. The molecular and cellular mechanisms that underlie vertebrate photoreceptor morphogenesis and the maintenance of the outer segment are largely unknown. The Crumbs (Crb) complex is a key regulator of apical membrane identity and size in epithelia and in Drosophila photoreceptors. Mutations in the human gene CRUMBS HOMOLOG 1 (CRB1) are associated with early and severe vision loss. Drosophila Crumbs and vertebrate Crb1 and Crumbs homolog 2 (Crb2) proteins are structurally similar, all are single pass transmembrane proteins with a large extracellular domain containing multiple laminin- and EGF-like repeats and a small intracellular domain containing a FERM-binding domain and a PDZ-binding domain. In order to begin to understand the role of the Crb family of proteins in vertebrate photoreceptors we generated stable transgenic zebrafish in which rod photoreceptors overexpress full-length Crb2a protein and several other Crb2a constructs engineered to lack specific domains. We examined the localization of Crb2a constructs and their effects on rod morphology. We found that only the full-length Crb2a protein approximated the normal localization of Crb2a protein apical to adherens junctions in the photoreceptor inner segment. Several Crb2a construct proteins localized abnormally to the outer segment and one construct localized abnormally to the cell body. Overexpression of full-length Crb2a greatly increased inner segment size while expression of several other constructs increased outer segment size. Our observations suggest that particular domains in Crb2a regulate its localization and thus may regulate its regionalized function. Our results also suggest that the PDZ-binding domain in Crb2a might bring a protein(s) into the Crb complex that alters the function of the FERM-binding domain.
登录
查看更多内容
DOI：
10.1083/jcb.200806009
发表时间：
2008-11-03
期刊：
The Journal of cell biology
影响因子：
--
作者：
Baker SA;Haeri M;Yoo P;Gospe SM 3rd;Skiba NP;Knox BE;Arshavsky VY
通讯作者：
Arshavsky VY
影响因子：
4.6
作者：
Hsu, Ya-Chu;Willoughby, John J.;Jensen, Abbie M.
通讯作者：
Jensen, Abbie M.
影响因子：
2.6
作者：
den Hollander, AI;Ghiani, M;Broccoli, V
通讯作者：
Broccoli, V
影响因子：
3.4
作者：
ROHLICH, P;ADAMUS, G;HARGRAVE, PA
通讯作者：
HARGRAVE, PA
DOI：
10.1073/pnas.97.21.11403
发表时间：
2000-10-10
影响因子：
11.1
作者：
Kawakami, K;Shima, A;Kawakami, N
通讯作者：
Kawakami, N