GCN5: a supervisor in all-inclusive control of vertebrate cell cycle progression through transcription regulation of various cell cycle-related genes
GCN5: a supervisor in all-inclusive control of vertebrate cell cycle progression through transcription regulation of various cell cycle-related genes
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DOI：
10.1016/j.gene.2004.12.007
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发表时间：
2005-02-28
期刊：
影响因子：
3.5
通讯作者：
Nakayama, T
中科院分区：
文献类型：
--
作者：
Kikuchi, H;Takami, Y;Nakayama, T
历史乙酰转移酶（historical acetyltransferases, HATs）参与核心组蛋白的乙酰化，这是真核生物通过改变染色质结构进行转录调控的重要事件。为了阐明GCN5和PCAF这两种酶在体内的参与作用，我们在基因靶向技术的帮助下，分别产生了GCN5和PCAF基因的纯合突变体Delta GCN5和Delta PCAF，它们分别缺乏GCN5和PCAF基因的两个等位基因。而pcaf缺乏对生长速率没有影响，gcn5缺乏导致DT40细胞生长速率延迟。FACS分析显示，Delta GCN5不仅处于S期的细胞数量减少，而且G1/S期的细胞周期进程受到抑制。RT-PCR分析显示，gcn5缺陷对G1/S期相关基因的转录产生相反的影响，即E2F-1、E2F-3、E2F-4、E2F-6、DP-2、cyclin A、cyclin D3、PCNA、cdc25B和p107的转录受到抑制；激活p27， c-myc，细胞周期蛋白D2和细胞周期蛋白G1。同样，这种缺陷对凋亡相关基因的转录产生相反的影响，即bc1-xL的表达减少，bc1-2的表达增加。免疫印迹分析显示，gcn5缺失导致K16/H2B和K9/H3乙酰化水平降低，K7/H2A、K18/H3、K23/H3、K27/H3、K8/H4和K12/H4乙酰化水平升高。这些结果表明，GCN5优先作为正常细胞周期进程的监管者，全面控制这些细胞周期相关基因以及凋亡相关基因的表达，可能是通过改变染色质结构，通过改变这些广泛分布的基因周围核心组蛋白的乙酰化状态来模拟的。(c) 2004 Elsevier B.V.版权所有
Historic acetyltransferases (HATs) are involved in the acetylation of core histones, which is an important event for transcription regulation through alterations in the chromatin structure in eukaryotes. To clarify participatory in vivo roles of two such enzymes known as GCN5 and PCAF, we generated homozygous DT40 mutants, Delta GCN5 and Delta PCAF, devoid of two alleles of each of the GCN5 and PCAF genes, respectively, with the help of gene targeting technique. While the PCAF-deficiency exhibited no effect on growth rate, the GCN5-deficiency caused delayed growth rate of DT40 cells. FACS analyses revealed not only that the number of cells in S phase decreased, but also that the cell cycle progression was suppressed at G1/S phase transition for Delta GCN5. RT-PCR analyses revealed that the GCN5-deficiency exhibited opposite influences on transcriptions of G1/S phase transition-related genes, i.e. repressions for E2F-1, E2F-3, E2F-4, E2F-6, DP-2, cyclin A, cyclin D3, PCNA, cdc25B and p107; and activations for p27, c-myc, cyclin D2 and cyclin G1. Similarly, the deficiency influenced oppositely transcriptions of apoptosis-related genes, i.e. decreased expression of bc1-xL and increased expression of bc1-2. Immunoblotting analyses using a number of anti-acetylated historic antisera revealed that the GCN5-deficiency led to decreased acetylation levels of K16/H2B and K9/H3, and increased those of K7/H2A, K18/H3, K23/H3, K27/H3, K8/H4 and K12/H4. These results indicate that GCN5 preferentially acts as a supervisor in the normal cell cycle progression having comprehensive control over expressions of these cell cycle-related genes, as well as apoptosis-related genes, probably via alterations in the chromatin structure, mimicked by changing acetylation status of core histones, surrounding these widely distributed genes. (c) 2004 Elsevier B.V. All rights reserved.