Giessl Andreas, Trojan Philipp, Rausch Sebastian, Pulvermüller Alexander, Wolfrum Uwe
Johannes Gutenberg-University, Institute of Zoology, Department of Cell and Matrix Biology, Mainz, Germany.
Vision Res. 2006 Dec;46(27):4502-9. doi: 10.1016/j.visres.2006.07.029. Epub 2006 Oct 6.
Centrins are members of a highly conserved subgroup of the EF-hand superfamily of Ca(2+)-binding proteins commonly associated with centrosome-related structures. In the retina, centrins are also prominent components of the photoreceptor cell ciliary apparatus. Centrin isoforms are differentially localized at the basal body and in the lumen of the connecting cilium. All molecular exchanges between the inner and outer segments occur through this narrow connecting cilium. Ca(2+)-activated centrin isoforms bind to the visual heterotrimeric G-protein transducin via an interaction with the betagamma-subunit. Ca(2+)-dependent assemblies of centrin/G-protein complexes may regulate the transducin movement through the connecting cilium. Formation of this complex represents a novel mechanism in regulation of translocation of signaling proteins in sensory cells, as well as a potential link between molecular trafficking and signal transduction in general.
中心蛋白是Ca(2+)结合蛋白EF手超家族中一个高度保守的亚组成员，通常与中心体相关结构有关。在视网膜中，中心蛋白也是光感受器细胞纤毛装置的重要组成部分。中心蛋白异构体在基体和连接纤毛的管腔中呈差异性定位。内外节之间的所有分子交换都通过这个狭窄的连接纤毛进行。Ca(2+)激活的中心蛋白异构体通过与βγ亚基相互作用，与视觉异源三聚体G蛋白转导蛋白结合。中心蛋白/G蛋白复合物的Ca(2+)依赖性组装可能调节转导蛋白通过连接纤毛的移动。这种复合物的形成代表了一种调节感觉细胞中信号蛋白转运的新机制，以及分子运输与信号转导之间的潜在联系。
