Interaction of PALE CRESS with PAP2/pTAC2 and PAP3/pTAC10 affects the accumulation of plastid-encoded RNA polymerase complexes in Arabidopsis.
Interaction of PALE CRESS with PAP2/pTAC2 and PAP3/pTAC10 affects the accumulation of plastid-encoded RNA polymerase complexes in Arabidopsis.
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DOI：
10.1111/nph.19243
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发表时间：
2023-09
期刊：
影响因子：
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通讯作者：
Xiaomin Wang;Yafei Qi;Na-Nv Liu;Qiaoxin Zhang;Sha Xie;Yang Lei;Bilang Li;Jingxia Shao;
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文献类型：
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作者：
Xiaomin Wang;Yafei Qi;Na-Nv Liu;Qiaoxin Zhang;Sha Xie;Yang Lei;Bilang Li;Jingxia Shao;
叶绿体中光合作用基因的转录主要由质体编码的RNA聚合酶（PEP）介导，PEP类似于原核类型的RNA聚合酶，但具有植物特异性的附属亚基，称为质体转录活性染色体蛋白（pTAC）或PEP相关蛋白（PAP）。然而，是否有其他因素参与PEP复合物的生物合成仍然未知。在这里，我们研究了一个必需的基因，PALE CRESS（PAC），在PEP复合物在叶绿体中的积累的功能。我们建立了拟南芥叶斑突变体，杂色6-1（var 6 -1），是PAC的亚型等位基因。出乎意料的是，我们发现一部分VAR 6/PAC与类囊体膜相关，在那里它与PEP复合物相互作用。PEP复合物的积累在var 6 -1和无效等位基因var 6 -2中都有缺陷。进一步的蛋白质相互作用分析证实VAR 6/PAC直接与PEP复合物的PAP 2/pTAC 2和PAP 3/pTAC 10亚基相互作用。此外，我们产生了可行的亚纯型等位基因的必需基因PAP 2/pTAC 2，并揭示了PAC和PAP 2/pTAC 2之间的遗传相互作用的光合作用基因的表达和PEP复合物的积累。我们的研究结果表明，VAR 6/PAC通过与PAP 2/pTAC 2和PAP 3/pTAC 10的相互作用影响PEP复合物的积累，并提供了新的见解PEP的积累和叶绿体发育。
The transcription of photosynthesis genes in chloroplasts is largely mediated by the plastid-encoded RNA polymerase (PEP), which resembles prokaryotic-type RNA polymerases, but with plant-specific accessory subunits known as plastid transcriptionally active chromosome proteins (pTACs) or PEP-associated proteins (PAPs). However, whether additional factors are involved in the biogenesis of PEP complexes remains unknown. Here, we investigated the function of an essential gene, PALE CRESS (PAC), in the accumulation of PEP complexes in chloroplasts. We established that an Arabidopsis leaf variegation mutant, variegated 6-1 (var6-1), is a hypomorphic allele of PAC. Unexpectedly, we revealed that a fraction of VAR6/PAC is associated with thylakoid membranes, where it interacts with PEP complexes. The accumulation of PEP complexes is defective in both var6-1 and the null allele var6-2. Further protein interaction assays confirmed that VAR6/PAC interacts directly with the PAP2/pTAC2 and PAP3/pTAC10 subunits of PEP complexes. Moreover, we generated viable hypomorphic alleles of the essential gene PAP2/pTAC2, and revealed a genetic interaction between PAC and PAP2/pTAC2 in photosynthesis gene expression and PEP complex accumulation. Our findings establish that VAR6/PAC affects PEP complex accumulation through interactions with PAP2/pTAC2 and PAP3/pTAC10, and provide new insights into the accumulation of PEP and chloroplast development.