AUTHOR=Zhou Xiaohong , Xie Jiamin , Xu Chao , Cao Xiuling , Zou Long-Hai , Zhou Mingbing 

TITLE=Artificial optimization of bamboo Ppmar2 transposase and host factors effects on Ppmar2 transposition in yeast

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.1004732

DOI=10.3389/fpls.2022.1004732

ISSN=1664-462X

ABSTRACT=<p><italic>Mariner-like elements</italic> (<italic>MLEs</italic>) are promising tools for gene cloning, gene expression, and gene tagging. We have characterized two <italic>MLE</italic> transposons from moso bamboo, <italic>Ppmar1</italic> and <italic>Ppmar2</italic>. <italic>Ppmar2</italic>, is smaller in size and has higher natural activities, thus making it a more potential genomic tool compared to <italic>Ppmar1</italic>. Using a two-component system consisting of a transposase expression cassette and a non-autonomous transposon cotransformed in yeast, we investigated the transposition activity of <italic>Ppmar2</italic> and created hyperactive transposases. Five out of 19 amino acid mutations in <italic>Ppmar2</italic> outperformed the wild-type in terms of catalytic activities, especially with the S347R mutant having 6.7-fold higher transposition activity. Moreover, 36 yeast mutants with single-gene deletion were chosen to screen the effects of the host factors on <italic>Ppmar2NA</italic> transposition. Compared to the control strain (<italic>his3Δ</italic>), the mobility of <italic>Ppmar2</italic> was greatly increased in 9 mutants and dramatically decreased in 7 mutants. The transposition ability in the <italic>efm1Δ</italic> mutant was 15-fold higher than in the control, while it was lowered to 1/66 in the <italic>rtt10Δ</italic> mutant. Transcriptomic analysis exhibited that <italic>EFM1</italic> defection led to the significantly impaired <italic>DDR2</italic>, <italic>HSP70</italic> expression and dramatically boosted <italic>JEN1</italic> expression, whereas <italic>RTT10</italic> defection resulted in significantly suppressed expression of <italic>UTP20</italic>, <italic>RPA190</italic> and <italic>RRP5</italic>. Protein methylation, chromatin and RNA transcription may affect the <italic>Ppmar2NA</italic> transposition efficiency in yeast. Overall, the findings provided evidence for transposition regulation and offered an alternative genomic tool for moso bamboo and other plants.</p>