1. Academic Validation
  2. Identification of LARK as a novel and conserved G-quadruplex binding protein in invertebrates and vertebrates

Identification of LARK as a novel and conserved G-quadruplex binding protein in invertebrates and vertebrates

  • Nucleic Acids Res. 2019 Aug 22;47(14):7306-7320. doi: 10.1093/nar/gkz484.
Kangkang Niu 1 2 Lijun Xiang 1 2 Ying Jin 1 2 Yuling Peng 1 2 Feng Wu 1 2 Wenhuan Tang 1 2 Xiaojuan Zhang 1 2 Huimin Deng 1 2 Hui Xiang 1 2 Sheng Li 1 2 Jian Wang 3 Qisheng Song 4 Qili Feng 1 2
Affiliations

Affiliations

  • 1 Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510631, China.
  • 2 Guangzhou Key Laboratory of Insect Development Regulation and Application Research, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510631, China.
  • 3 Department of Entomology, University of Maryland, College Park, MD 20742, USA.
  • 4 Division of Plant Sciences, University of Missouri, Columbia, MO 65211, USA.
Abstract

Double-stranded DNAs are usually present in the form of linear B-form double-helix with the base pairs of adenine (A) and thymine (T) or cytosine (C) and guanine (G), but G-rich DNA can form four-stranded G-quadruplex (G4) structures, which plays important roles in transcription, replication, translation and protection of telomeres. In this study, a RNA recognition motif (RRM)-containing protein, BmLARK, was identified and demonstrated to bind G4 structures in the promoters of a transcription factor BmPOUM2 and other three unidentified genes of Bombyx mori, as well as three well-defined G4 structures in the human genes. Homologous LARKs from Bombyx mori, Drosophila melanogaster, Mus musculus and Homo sapiens bound G4 structures in BmPOUM2 and other genes in B. mori and H. sapiens. Upon binding, LARK facilitated the formation and stability of the G4 structure, enhancing the transcription of target genes. The G4 structure was visualized in vivo in cells and testis from invertebrate B. mori and vertebrate Chinese hamster ovary (CHO) cells. The results of this study strongly suggest that LARK is a novel and conserved G4-binding protein and that the G4 structure may have developed into an elaborate epigenetic mechanism of gene transcription regulation during evolution.

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