The PHD finger protein VRN5 functions in the epigenetic silencing of Arabidopsis FLC
The PHD finger protein VRN5 functions in the epigenetic silencing of Arabidopsis FLC
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DOI：
10.1016/j.cub.2006.11.052
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发表时间：
2007-01-09
期刊：
影响因子：
9.2
通讯作者：
Dean, Caroline
中科院分区：
文献类型：
--
作者：
Greb, Thomas;Mylne, Joshua S.;Dean, Caroline
春化作用，即通过延长冬季的寒冷加速开花，确保植物在有利的春季条件下开花。在拟南芥的春化过程中，低温以涉及春化不敏感3（VIN 3）[3]的机制抑制FLC表达[1，2]，并且这种抑制通过涉及春化2（VRN 2）、Su（z）12同源物、春化1（VRN 1）和类异染色质蛋白1的多梳状染色质调节的表观遗传学维持[4-8]。为了进一步阐述冷阻遏如何触发表观遗传沉默，我们靶向了在长时间寒冷结束时和随后发育后导致FLC错误表达的突变。这鉴定了VERNALIZATION 5（VRN 5），一种PHD指蛋白和VIN 3的同源物。我们的研究结果表明，在长时间的寒冷，VRN 5和VIN 3形成一个异源二聚体建立春化诱导的染色质修饰，组蛋白脱乙酰化，和H3赖氨酸27三甲基化所需的表观遗传沉默的FLC。双突变体和FLCmisexpression分析揭示了额外的VRN 5功能，FLC依赖性和非依赖性，并表明空间复杂性FLC表观遗传沉默与VRN 5作为一个共同的组成部分，在多个途径。
Vernalization, the acceleration of flowering by the prolonged cold of winter, ensures that plants flower in favorable spring conditions. During vernalization in Arabidopsis, cold temperatures repress FLOWERING LOCUS C (FLC) expression [1, 2] in a mechanism involving VERNALIZATION INSENSITIVE 3 (VIN3) [3], and this repression is epigenetically maintained by a Polycomb-like chromatin regulation involving VERNALIZATION 2 (VRN2), a Su(z)12 homolog, VERNALIZATION 1 (VRN1), and LIKE-HETEROCHROMATIN PROTEIN 1 [4-8]. In order to further elaborate how cold repression triggers epigenetic silencing, we have targeted mutations that result in FLC misexpression both at the end of the prolonged cold and after subsequent development. This identified VERNALIZATION 5 (VRN5), a PHD finger protein and homolog of VIN3. Our results suggest that during the prolonged cold, VRN5 and VIN3 form a heterodimer necessary for establishing the vernalization-induced chromatin modifications, histone deacetylation, and H3 lysine 27 trimethylation required for the epigenetic silencing of FLC. Double mutant and FLCmisexpression analyses reveal additional VRN5 functions, both FLC-dependent and -independent, and indicate a spatial complexity to FLC epigenetic silencing with VRN5 acting as a common component in multiple pathways.