Institute of Plant and Microbial Biology, Academia Sinica, Taipei, 11529, Taiwan.
Biotechnology Center, National Chung-Hsing University, Taichung, 40227, Taiwan.
BMC Genomics. 2021 Nov 22;22(1):845. doi: 10.1186/s12864-021-08160-6.
Covalent modifications of core histones govern downstream DNA-templated processes such as transcription by altering chromatin structure and function. Previously, we reported that the plant homeodomain protein ALFIN-LIKE 6 (AL6), a bona fide histone reader that preferentially binds trimethylated lysin 4 on histone 3 (H3K4me3), is critical for recalibration of cellular phosphate (Pi) homeostasis and root hair elongation under Pi-deficient conditions.
Here, we demonstrate that AL6 is also involved in the response of Arabidopsis seedlings to jasmonic acid (JA) during skotomorphogenesis, possibly by modulating chromatin dynamics that affect the transcriptional regulation of JA-responsive genes. Dark-grown al6 seedlings showed a compromised reduction in hypocotyl elongation upon exogenously supplied JA, a response that was calibrated by the availability of Pi in the growth medium. A comparison of protein profiles between wild-type and al6 mutant seedlings using a quantitative Chromatin Enrichment for Proteomics (ChEP) approach, that we modified for plant tissue and designated ChEP-P (ChEP in Plants), yielded a comprehensive suite of chromatin-associated proteins and candidates that may be causative for the mutant phenotype.
Altered abundance of proteins involved in chromatin organization in al6 seedlings suggests a role of AL6 in coordinating the deposition of histone variants upon perception of internal or environmental stimuli. Our study shows that ChEP-P is well suited to gain holistic insights into chromatin-related processes in plants. Data are available via ProteomeXchange with identifier PXD026541.
核心组蛋白的共价修饰通过改变染色质结构和功能来控制下游的 DNA 模板过程，如转录。此前，我们报道植物同源域蛋白 ALFIN-LIKE 6（AL6）是一种真正的组蛋白阅读器，它优先结合组蛋白 3（H3）上的三甲基赖氨酸 4（H3K4me3），对于在缺磷条件下细胞磷（Pi）稳态的重新校准和根毛伸长是至关重要的。
在这里，我们证明 AL6 也参与了拟南芥幼苗在 skotomorphogenesis 期间对茉莉酸（JA）的反应，可能通过调节影响 JA 响应基因转录调控的染色质动力学。黑暗中生长的 al6 幼苗在体外添加 JA 时，下胚轴伸长的减少受到损害，这种反应由生长培养基中 Pi 的可用性来校准。使用定量染色质富集蛋白质组学（ChEP）方法（我们为植物组织修改并命名为 ChEP-P（植物中的 ChEP））对野生型和 al6 突变体幼苗进行蛋白质图谱比较，得到了一套全面的染色质相关蛋白和候选蛋白，这些蛋白和候选蛋白可能是突变体表型的原因。
al6 幼苗中参与染色质组织的蛋白质丰度的改变表明，AL6 在协调内部或环境刺激感知时组蛋白变体的沉积中起作用。我们的研究表明，ChEP-P 非常适合全面了解植物中的染色质相关过程。数据可通过 ProteomeXchange 以标识符 PXD026541 获得。
