Genetic analysis of the Holliday junction resolvases Hje and Hjc in Sulfolobus islandicus

TY - JOUR

T1 - Genetic analysis of the Holliday junction resolvases Hje and Hjc in Sulfolobus islandicus

AU - Huang, Qihong

AU - Li, Yansheng

AU - Zeng, Chaoning

AU - Song, Tengteng

AU - Yan, Zhou

AU - Ni, Jinfeng

AU - She, Qunxin

AU - Shen, Yulong

PY - 2015/3

Y1 - 2015/3

N2 - The in vivo functions of Hje and Hjc, two Holliday junction resolvases in Sulfolobus islandicus were investigated. We found that deletion of either hje or hjc had no effect on normal cell growth, while deletion of both hje and hjc is lethal. Although Hjc is the conserved resolvase in all archaea, the hje deletion rather than hjc deletion rendered cells more sensitive to DNA-damaging agents such as hydroxyurea, cisplatin, and methyl methanesulfonate than the wild type (WT). Intriguingly, the sensitivity of Δhje could not be rescued by ectopic expression of Hje from a plasmid and Hje overexpression slowed growth and large cells appeared with more than two genome equivalents. We showed that Hje was maintained at a low level in WT cells. Furthermore, transcriptomic microarray analysis revealed that the abundance of transcripts of many genes including those involved in DNA replication, repair, transcription regulation, and cell division changed drastically in the Hje-overexpressed strain. However, only limited genes were up- or downregulated in the hje deletion strain. Our findings collectively suggest that Hje is the primary resolvase involved in DNA repair and its expression must be tightly controlled in cells.

AB - The in vivo functions of Hje and Hjc, two Holliday junction resolvases in Sulfolobus islandicus were investigated. We found that deletion of either hje or hjc had no effect on normal cell growth, while deletion of both hje and hjc is lethal. Although Hjc is the conserved resolvase in all archaea, the hje deletion rather than hjc deletion rendered cells more sensitive to DNA-damaging agents such as hydroxyurea, cisplatin, and methyl methanesulfonate than the wild type (WT). Intriguingly, the sensitivity of Δhje could not be rescued by ectopic expression of Hje from a plasmid and Hje overexpression slowed growth and large cells appeared with more than two genome equivalents. We showed that Hje was maintained at a low level in WT cells. Furthermore, transcriptomic microarray analysis revealed that the abundance of transcripts of many genes including those involved in DNA replication, repair, transcription regulation, and cell division changed drastically in the Hje-overexpressed strain. However, only limited genes were up- or downregulated in the hje deletion strain. Our findings collectively suggest that Hje is the primary resolvase involved in DNA repair and its expression must be tightly controlled in cells.

U2 - 10.1007/s00792-015-0734-5

DO - 10.1007/s00792-015-0734-5

M3 - Journal article

C2 - 25644236

SN - 1431-0651

VL - 19

SP - 505

EP - 514

JO - Extremophiles

JF - Extremophiles

IS - 2

ER -