C2 domain protein MIN1 promotes eyespot organization in Chlamydomonas reinhardtii.
C2 domain protein MIN1 promotes eyespot organization in Chlamydomonas reinhardtii.
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C2 结构域蛋白 MIN1 促进莱茵衣藻的眼斑组织。
DOI：
10.1128/ec.00118-08
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
Dieckmann,CarolL
中科院分区：
文献类型：
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作者：
Mittelmeier,TelsaM;Berthold,Peter;Danon,Avihai;Lamb,MaryRose;Levitan,Alexander;Rice,MichaelE;Dieckmann,CarolL
双鞭毛虫、单细胞绿色藻类中感光眼点的组装和不对称定位莱茵衣藻需要质膜中光感受器和叶绿体中色素颗粒/类囊体膜层的协调组织。min 1（小眼）突变细胞包含异常小、混乱的眼点，其中叶绿体被膜和质膜不再并列。MIN 1基因，这里确定的表型救援，编码的蛋白质与N-末端C2结构域和C-末端LysM结构域分开的跨膜序列。这种新的结构域架构导致的假设，MIN 1是在质膜或叶绿体包膜，膜协会的C2域促进适当的眼点组织。保守的C2结构域环残基的突变破坏了MIN 1 C2结构域与叶绿体被膜在苔藓细胞中的关联，但并没有废除眼斑大会inChlamydium。在MIN 1缺失细胞中，通道视紫红质-1（ChR 1）感光细胞水平降低，表明MIN 1在ChR 1表达和/或稳定性中的作用。然而，ChR 1的本地化只有最低限度的干扰，在光合自养生长ofmin 1细胞，条件下，色素颗粒层是混乱的。这些数据是一致的假设，无论是MIN 1，也没有适当的组织的质体成分的眼点是必不可少的本地化的ChR 1。
Assembly and asymmetric localization of the photosensory eyespot in the biflagellate, unicellular green algaChlamydomonas reinhardtiirequires coordinated organization of photoreceptors in the plasma membrane and pigment granule/thylakoid membrane layers in the chloroplast.min1(mini-eyed) mutant cells contain abnormally small, disorganized eyespots in which the chloroplast envelope and plasma membrane are no longer apposed. TheMIN1gene, identified here by phenotypic rescue, encodes a protein with an N-terminal C2 domain and a C-terminal LysM domain separated by a transmembrane sequence. This novel domain architecture led to the hypothesis that MIN1 is in the plasma membrane or the chloroplast envelope, where membrane association of the C2 domain promotes proper eyespot organization. Mutation of conserved C2 domain loop residues disrupted association of the MIN1 C2 domain with the chloroplast envelope in moss cells but did not abolish eyespot assembly inChlamydomonas. Inmin1null cells, channelrhodopsin-1 (ChR1) photoreceptor levels were reduced, indicating a role for MIN1 in ChR1 expression and/or stability. However, ChR1 localization was only minimally disturbed during photoautotrophic growth ofmin1cells, conditions under which the pigment granule layers are disorganized. The data are consistent with the hypothesis that neither MIN1 nor proper organization of the plastidic components of the eyespot is essential for localization of ChR1.