作者: Jing, Lingyun ; Qin, Yali ; Dong, Xiaochuan ; Huang, Jiaojuan ; Chen, Qingchuan ; He, Ximiao ; Yang, Chengxuan ; Lu, Manman ; Qu, Jing ; Yang, Zhenhua ; Xiang, Zhengkai ; Guan, Fei

Poly (ADP-ribose) polymerase-1 (PARP1) is a nuclear protein that attaches negatively charged poly (ADP-ribose) (PAR) to itself and other target proteins. While its function in DNA damage repair is well established, its role in target chromatin recognition and regulation of gene expression remains to be better understood. This study showed that PARP1 interacts with SET1/MLL complexes by binding directly to WDR5. Notably, although PARP1 does not modulate WDR5 PARylation or the global level of H3K4 methylation, it exerts locus-specific effects on WDR5 binding and H3K4 methylation. Interestingly, PARP1 and WDR5 show extensive co-localization on chromatin, with WDR5 facilitating the recognition and expression of target genes regulated by PARP1. Furthermore, we demonstrated that inhibition of the WDR5 Win site impedes the interaction between PARP1 and WDR5, thereby inhibiting PARP1 from binding to target genes. Finally, the combined inhibition of the WDR5 Win site and PARP shows a profound inhibitory effect on the proliferation of cancer cells. These findings illuminate intricate mechanisms underlying chromatin recognition, gene transcription, and tumorigenesis, shedding light on previously unrecognized roles of PARP1 and WDR5 in these processes.

2024-06-01·Cell Death & Differentiation

The PML1-WDR5 axis regulates H3K4me3 marks and promotes stemness of estrogen receptor-positive breast cancer

Article

作者: Seachrist, Darcie D ; Keri, Ruth A ; Kao, Hung-Ying ; Wang, Han ; Adams, Joshua A ; Cao, Kaixiang ; Pai, Chun-Peng ; Agarwal, Neel ; Liu, Zhenghao ; Schiemann, William P

AbstractThe alternative splicing of PML precursor mRNA gives rise to various PML isoforms, yet their expression profile in breast cancer cells remains uncharted. We discovered that PML1 is the most abundant isoform in all breast cancer subtypes, and its expression is associated with unfavorable prognosis in estrogen receptor-positive (ER+) breast cancers. PML depletion reduces cell proliferation, invasion, and stemness, while heterologous PML1 expression augments these processes and fuels tumor growth and resistance to fulvestrant, an FDA-approved drug for ER+ breast cancer, in a mouse model. Moreover, PML1, rather than the well-known tumor suppressor isoform PML4, rescues the proliferation of PML knockdown cells. ChIP-seq analysis reveals significant overlap between PML-, ER-, and Myc-bound promoters, suggesting their coordinated regulation of target gene expression, including genes involved in breast cancer stem cells (BCSCs), such as JAG1, KLF4, YAP1, SNAI1, and MYC. Loss of PML reduces BCSC-related gene expression, and exogenous PML1 expression elevates their expression. Consistently, PML1 restores the association of PML with these promoters in PML-depleted cells. We identified a novel association between PML1 and WDR5, a key component of H3K4 methyltransferase (HMTs) complexes that catalyze H3K4me1 and H3K4me3. ChIP-seq analyses showed that the loss of PML1 reduces H3K4me3 in numerous loci, including BCSC-associated gene promoters. Additionally, PML1, not PML4, re-establishes the H3K4me3 mark on these promoters in PML-depleted cells. Significantly, PML1 is essential for recruiting WDR5, MLL1, and MLL2 to these gene promoters. Inactivating WDR5 by knockdown or inhibitors phenocopies the effects of PML1 loss, reducing BCSC-related gene expression and tumorsphere formation and enhancing fulvestrant’s anticancer activity. Our findings challenge the conventional understanding of PML as a tumor suppressor, redefine its role as a promoter of tumor growth in breast cancer, and offer new insights into the unique roles of PML isoforms in breast cancer.

2024-03-01·Cell Reports

Deficiency of lncRNA MERRICAL abrogates macrophage chemotaxis and diabetes-associated atherosclerosis

Article

作者: de Oliveira Vaz, Camila ; Assa, Carmel ; Tzani, Aspasia ; Cheng, Henry S ; Zhuang, Rulin ; Plutzky, Jorge ; Hamburg, Naomi M ; Hu, Yi ; Lee, Kwangwoon ; Eley, Samuel ; Wu, Winona ; Sabatine, Marc S ; Sausen, Grasiele ; McCoy, Michael G ; Pérez-Cremades, Daniel ; Chen, Jingshu ; Randhawa, Vinay ; Feinberg, Mark W ; Jamaiyar, Anurag

Diabetes-associated atherosclerosis involves excessive immune cell recruitment and plaque formation. However, the mechanisms remain poorly understood. Transcriptomic analysis of the aortic intima in Ldlr^-/- mice on a high-fat, high-sucrose-containing (HFSC) diet identifies a macrophage-enriched nuclear long noncoding RNA (lncRNA), MERRICAL (macrophage-enriched lncRNA regulates inflammation, chemotaxis, and atherosclerosis). MERRICAL expression increases by 249% in intimal lesions during progression. lncRNA-mRNA pair genomic mapping reveals that MERRICAL positively correlates with the chemokines Ccl3 and Ccl4. MERRICAL-deficient macrophages exhibit lower Ccl3 and Ccl4 expression, chemotaxis, and inflammatory responses. Mechanistically, MERRICAL guides the WDR5-MLL1 complex to activate CCL3 and CCL4 transcription via H3K4me3 modification. MERRICAL deficiency in HFSC diet-fed Ldlr^-/- mice reduces lesion formation by 74% in the aortic sinus and 86% in the descending aorta by inhibiting leukocyte recruitment into the aortic wall and pro-inflammatory responses. These findings unveil a regulatory mechanism whereby a macrophage-enriched lncRNA potently inhibits chemotactic responses, alleviating lesion progression in diabetes.

项与 WDR5 x MLL1 相关的新闻（医药）

2022-09-15

·生物谷

iScience：陈勇团队揭示DPY30促进MLL复合物甲基转移酶活性的分子机制

H3K4甲基化修饰对增强子活性调控、转录激活和细胞命运决定起关键作用，其异常会导致多种白血病和恶性肿瘤的发生。H3K4甲基化修饰主要是由MLL家族蛋白催化产生。 H3K4甲基化修饰对增强子活性调控、转录激活和细胞命运决定起关键作用，其异常会导致多种白血病和恶性肿瘤的发生。H3K4甲基化修饰主要是由MLL家族蛋白催化产生。MLL家族蛋白自身的甲基转移酶活性很低，需要与WDR5、RBBP5、ASH2L、DPY30等调节亚基形成复合物，才能有效发挥酶活。WDR5、RBBP5、ASH2L等亚基参与调控MLL蛋白酶活的分子机制在过去得到了充分的研究，但DPY30作为复合物中最小的蛋白（只有99个氨基酸）其发挥的作用和调节机制尚不明确。近日，中国科学院分子细胞科学卓越创新中心（生物化学与细胞生物学研究所）陈勇研究组在 iScience 期刊发表了题为：DPY30 acts as an ASH2L-specific stabilizer to stimulate the enzyme activity of MLL family methyltransferases on different substrates 的研究论文，揭示了DPY30促进MLL复合物甲基转移酶活性的分子机制。在这项研究中，研究团队发现DPY30可以不同程度地增强MLL1复合物在不同底物上的活性。在核小体底物上，DPY30能提高MLL复合物的催化效率逾27倍；在组蛋白多肽、H3或组蛋白八聚体水平上，DPY30仅能提高催化效率约1.8倍。研究团队继而通过交联质谱、小角散射、结构预测、动力学模拟等多种方法阐明了DPY30通过多种机制来调控复合物的甲基转移酶活性。首先，DPY30与ASH2L的多个结构域结合，增加了ASH2L的结构紧致性和热稳定性；DPY30稳定后的ASH2L与RBBP5结合力增强，促进MLL1复合物组装形成一个更紧凑和更稳定的复合物，导致DPY30可以微调MLL1复合物在组蛋白多肽、H3、组蛋白八聚体上的酶活。其次，DPY30稳定后的ASH2L获得了与组蛋白H3 N端尾巴（1-40）和核小体DNA结合的新的作用界面，确保核小体H3的尾部准确且稳定地进入MLLSET的催化口袋，从而极大地促进MLL1复合物甲基化核小体的活性，揭示了DPY30特异性促进MLL1复合物在核小体上酶活的机制。 DPY30促进MLL复合物甲基转移酶活性的分子机制 DPY30在多种癌症中高表达，之前的研究表明DPY30的促癌效应与H3K4甲基化修饰相关。在癌细胞中敲低DPY30，H3K4甲基化修饰水平降低，癌细胞增殖减慢；回补DPY30，H3K4甲基化修饰水平增加，癌细胞增殖增快。因此，该研究中揭示的DPY30调控MLL复合物甲基转移酶活性的分子机制可以为理解相关癌症发病机制提供理论基础，以及为相关癌症的治疗提供新的设计思路和设计靶点。中科院分子细胞卓越中心博士生赵利杰为论文第一作者，陈勇研究员为该论文的通讯作者。该研究工作获得中科院战略性先导计划和国家自然科学基金委的经费资助。该研究得到张江实验室国家蛋白质科学研究（上海）设施BL19U2小角散射线站、质谱分析系统和规模化蛋白质制备系统的支持和帮助。