School of Life Sciences, Jiangsu University, 301# Xuefu Road, Zhenjiang 212013, China.
School of Life Sciences, Jiangsu University, 301# Xuefu Road, Zhenjiang 212013, China.
J Insect Physiol. 2022 Oct;142:104424. doi: 10.1016/j.jinsphys.2022.104424. Epub 2022 Jul 22.
Solar ultraviolet radiation (UV) can cause DNA damage in microorganisms. Flap endonuclease 1 (FEN1) is a structure-specific nuclease and plays important roles in DNA replication and repair. At present, the properties and functions of FEN1 have not been characterized in detail in invertebrates such as Bombyx mori. In this study, Bombyx mori FEN1 (BmFEN1) was expressed in E. coli, and was shown to have nuclease activity that nonspecifically cleaved DNA in vitro. However, inside the cell, BmFEN1 did not cleave DNA randomly. Truncated BmFEN1 missing the nuclear localization signal (346-380 aa) still had the nuclease activity, but was no longer precisely localized to the sites of UV-induced DNA damage. It was further found that BmFEN1 favored the faster repair of UV-damaged DNA. The present study will provide a reference for further understanding the functions of BmFEN1 and UV-induced DNA damage repair mechanisms in insects.
太阳紫外线（UV）会导致微生物中的 DNA 损伤。核酸内切酶 1（FEN1）是一种结构特异性核酸内切酶，在 DNA 复制和修复中发挥重要作用。目前，在无脊椎动物如家蚕中，尚未详细表征 FEN1 的特性和功能。在本研究中，在大肠杆菌中表达了家蚕 FEN1（BmFEN1），并证明其具有体外非特异性切割 DNA 的核酸酶活性。然而，在细胞内，BmFEN1 不会随机切割 DNA。缺失核定位信号（346-380 aa）的截短 BmFEN1 仍具有核酸酶活性，但不再精确定位于 UV 诱导的 DNA 损伤部位。进一步发现，BmFEN1 有利于更快地修复 UV 损伤的 DNA。本研究将为进一步了解 BmFEN1 的功能以及昆虫中 UV 诱导的 DNA 损伤修复机制提供参考。
