A rhodopsin-guanylyl cyclase gene fusion functions in visual perception in a fungus.
A rhodopsin-guanylyl cyclase gene fusion functions in visual perception in a fungus.
复制标题
DOI：
10.1016/j.cub.2014.04.009
复制
发表时间：
2014-06-02
期刊：
影响因子：
9.2
通讯作者：
Gomes, Suely L.
中科院分区：
文献类型：
--
作者：
Avelar, Gabriela M.;Schumacher, Robert I.;Zaini, Paulo A.;Leonard, Guy;Richards, Thomas A.;Gomes, Suely L.
感知光是视觉系统的基本特性，动物的视觉几乎完全基于视蛋白色素。视紫红质也作为一个光感受器连接到趋光性在绿色藻类，并已牵连的化学手段作为光传感器在鞭毛游动孢子的真菌Allomycesreticulatus，然而，在这些真菌的信号传导机制仍然未知。在这里，我们使用基因组测序和分子抑制实验与光敏感表型研究相结合，以检查密切相关的真菌Blastocladiella emersonii的视觉感知中涉及的信号通路。我们的数据表明，在这些真菌中，光感知是由一种新的基因融合（BeGC 1）的功能，I型（微生物）视紫红质结构域和鸟苷酸环化酶催化结构域。视紫红质功能的光漂白防止暴露于绿色光的真菌游动孢子的cGMP水平和趋光性的积累，而鸟苷酸环化酶活性的抑制对真菌趋光性产生负面影响。免疫荧光显微镜定位的BeGC 1蛋白的游动孢子眼点的外表面定位靠近游泳鞭毛的基础，表明这是一个光感受器的脂滴组成。两者合计，这些数据表明，芽枝菌门真菌有一个cGMP信号通路参与趋光性类似的脊椎动物视觉信号级联，但组成的蛋白质结构域组件安排作为一种新的基因融合架构和遥远的进化祖先II型视紫红质的动物。视紫红质-鸟苷酸环化酶基因融合参与了B. emersonii趋光性视紫红质融合蛋白BeGC 1定位于游动孢子的眼斑器。使用基因组测序、分子抑制和光敏表型实验，结合免疫定位数据，显示I型视紫红质-鸟苷酸环化酶融合蛋白定位于Blastocladiella emersonii的游动孢子中的“眼点”，并参与绿色光趋光性。
Sensing light is the fundamental property of visual systems, with vision in animals being based almost exclusively on opsin photopigments. Rhodopsin also acts as a photoreceptor linked to phototaxis in green algae and has been implicated by chemical means as a light sensor in the flagellated swimming zoospores of the fungus Allomyces reticulatus; however, the signaling mechanism in these fungi remains unknown. Here we use a combination of genome sequencing and molecular inhibition experiments with light-sensing phenotype studies to examine the signaling pathway involved in visual perception in the closely related fungus Blastocladiella emersonii. Our data show that in these fungi, light perception is accomplished by the function of a novel gene fusion (BeGC1) of a type I (microbial) rhodopsin domain and guanylyl cyclase catalytic domain. Photobleaching of rhodopsin function prevents accumulation of cGMP levels and phototaxis of fungal zoospores exposed to green light, whereas inhibition of guanylyl cyclase activity negatively affects fungal phototaxis. Immunofluorescence microscopy localizes the BeGC1 protein to the external surface of the zoospore eyespot positioned close to the base of the swimming flagellum, demonstrating this is a photoreceptive organelle composed of lipid droplets. Taken together, these data indicate that Blastocladiomycota fungi have a cGMP signaling pathway involved in phototaxis similar to the vertebrate vision-signaling cascade but composed of protein domain components arranged as a novel gene fusion architecture and of distant evolutionary ancestry to type II rhodopsins of animals. A rhodopsin-guanylate cyclase gene fusion is involved in B. emersonii phototaxis The rhodopsin fusion protein BeGC1 is localized to the zoospore eyespot apparatus Endogenous retinal substitution by retinalA1 reconstitutes green light phototaxis Zoospore phototaxis uses cGMP as a second messenger similar to vertebrate vision Avelar et al. use genome sequencing, molecular inhibition, and light-sensing phenotype experiments, combined with immunolocalization data, to show that a type I rhodopsin-guanylyl cyclase fusion protein localizes to the “eyespot” and is involved in green light phototaxis in zoospores of the Blastocladiomycete fungus Blastocladiella emersonii.
登录
查看更多内容
DOI：
10.1016/j.cub.2009.12.006
发表时间：
2010-02-09
期刊：
Current biology : CB
影响因子：
--
作者：
Fain GL;Hardie R;Laughlin SB
通讯作者：
Laughlin SB
DOI：
10.1073/pnas.1306826110
发表时间：
2013-08-13
影响因子：
11.1
作者：
Devine, Erin L.;Oprian, Daniel D.;Theobald, Douglas L.
通讯作者：
Theobald, Douglas L.
影响因子：
--
作者：
Ma X;Beuve A;van den Akker F
通讯作者：
van den Akker F
DOI：
10.1016/s0167-4781(02)00297-x
发表时间：
2002-06-07
期刊：
BIOCHIMICA ET BIOPHYSICA ACTA-GENE STRUCTURE AND EXPRESSION
影响因子：
--
作者：
Fietto, LG;Pugliese, L;Gomes, SL
通讯作者：
Gomes, SL
影响因子：
2.8
作者：
James, Timothy Y.;Letcher, Peter M.;Vilgalys, Rytas
通讯作者：
Vilgalys, Rytas