A single N-terminal amino acid determines the distinct roles of histones H3 and H3.3 in the Drosophila male germline stem cell lineage.
A single N-terminal amino acid determines the distinct roles of histones H3 and H3.3 in the Drosophila male germline stem cell lineage.
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DOI：
10.1371/journal.pbio.3002098
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发表时间：
2023-05
期刊：
影响因子：
9.8
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中科院分区：
文献类型：
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成体干细胞经历不对称细胞分裂以产生具有不同细胞命运的2个子细胞：一个能够自我更新，另一个致力于分化。这种微妙的平衡失调可能导致癌症和组织退化。在果蝇雄性生殖系干细胞（GSC）的不对称分裂过程中，先前存在的（旧的）和新合成的组蛋白H3是差异分离的，而旧的和新的组蛋白变体H3.3更平等地遗传。然而，这些不同的遗传模式的基础仍然未知。在这里，我们报告了H3和H3.3的N-末端尾部对于它们的遗传模式以及GSC的维持和适当的分化是至关重要的。H3和H3.3在其N-末端的第31位不同，H3为丙氨酸，H3.3为丝氨酸。通过交换这2个氨基酸，我们产生了2个突变组蛋白（即，H3 A31 S和H3.3S31A）。在早期生殖细胞系中表达后，我们鉴定出相反的表型：表达H3 A31 S的睾丸中早期生殖细胞的过度增殖和表达H3.3S31A的睾丸中生殖细胞的显著损失。在表达H3 A31 S的GSC中，由于在DNA复制过程中姐妹染色单体之间的旧组蛋白的错误掺入，不对称H3遗传被破坏。此外，H3.3S31A突变加速GSC中的旧组蛋白更新。最后，使用改良的染色质免疫切割试验对早期生殖细胞进行检测，我们发现与H3相比，H3 A31 S在启动子和转录起始位点的占据率增强，而与H3.3相比，H3.3S31A在转录沉默的基因间区域更加富集。总体而言，这些结果表明H3和H3.3的第31个氨基酸对于其适当的基因组占有率和功能至关重要。总之，我们的研究结果表明，在内源性干细胞谱系中，H3和H3.3之间的N-末端尾部的不同氨基酸组成具有关键作用，并提供了对适当组蛋白遗传在指定细胞命运和调节细胞分化中的重要性的见解。在果蝇雄性生殖系干细胞（GSC）的不对称分裂过程中，组蛋白H3优先由GSC遗传，而组蛋白H3.3则不是。这项研究表明，一个单一的N-末端氨基酸（残基31）是其独特的遗传模式的基础，与GSC的维持和分化的潜在影响。
Adult stem cells undergo asymmetric cell divisions to produce 2 daughter cells with distinct cell fates: one capable of self-renewal and the other committed for differentiation. Misregulation of this delicate balance can lead to cancer and tissue degeneration. During asymmetric division of Drosophila male germline stem cells (GSCs), preexisting (old) and newly synthesized histone H3 are differentially segregated, whereas old and new histone variant H3.3 are more equally inherited. However, what underlies these distinct inheritance patterns remains unknown. Here, we report that the N-terminal tails of H3 and H3.3 are critical for their inheritance patterns, as well as GSC maintenance and proper differentiation. H3 and H3.3 differ at the 31st position in their N-termini with Alanine for H3 and Serine for H3.3. By swapping these 2 amino acids, we generated 2 mutant histones (i.e., H3A31S and H3.3S31A). Upon expressing them in the early-stage germline, we identified opposing phenotypes: overpopulation of early-stage germ cells in the H3A31S-expressing testes and significant germ cell loss in testes expressing the H3.3S31A. Asymmetric H3 inheritance is disrupted in the H3A31S-expressing GSCs, due to misincorporation of old histones between sister chromatids during DNA replication. Furthermore, H3.3S31A mutation accelerates old histone turnover in the GSCs. Finally, using a modified Chromatin Immunocleavage assay on early-stage germ cells, we found that H3A31S has enhanced occupancy at promoters and transcription starting sites compared with H3, while H3.3S31A is more enriched at transcriptionally silent intergenic regions compared to H3.3. Overall, these results suggest that the 31st amino acids for both H3 and H3.3 are critical for their proper genomic occupancy and function. Together, our findings indicate a critical role for the different amino acid composition of the N-terminal tails between H3 and H3.3 in an endogenous stem cell lineage and provide insights into the importance of proper histone inheritance in specifying cell fates and regulating cellular differentiation. During asymmetric division of Drosophila male germline stem cells (GSCs), histone H3 is preferentially inherited by the GSC, while histone H3.3 is not. This study reveals that a single N-terminal amino acid (residue 31) underlies their distinct inheritance patterns, with potential implications for GSC maintenance and differentiation.
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影响因子：
4.8
作者：
Demarco, Rafael S.;Eikenes, Asmund H.;Haglund, Kaisa;Jones, D. Leanne
通讯作者：
Jones, D. Leanne
影响因子：
64.5
作者：
Goldberg AD;Banaszynski LA;Noh KM;Lewis PW;Elsaesser SJ;Stadler S;Dewell S;Law M;Guo X;Li X;Wen D;Chapgier A;DeKelver RC;Miller JC;Lee YL;Boydston EA;Holmes MC;Gregory PD;Greally JM;Rafii S;Yang C;Scambler PJ;Garrick D;Gibbons RJ;Higgs DR;Cristea IM;Urnov FD;Zheng D;Allis CD
通讯作者：
Allis CD
影响因子：
10.5
作者：
Alabert C;Barth TK;Reverón-Gómez N;Sidoli S;Schmidt A;Jensen ON;Imhof A;Groth A
通讯作者：
Groth A
DOI：
10.1073/pnas.172403699
发表时间：
2002-12-10
影响因子：
11.1
作者：
Ahmad, K;Henikoff, S
通讯作者：
Henikoff, S
影响因子：
4.5
作者：
Feng L;Shi Z;Chen X
通讯作者：
Chen X