The Identification of a Target Gene of the Transcription Factor KojR and Elucidation of Its Role in Carbon Metabolism for Kojic Acid Biosynthesis in <i>Aspergillus oryzae</i>

DNA-binding transcription factors are broadly characterized as proteins that bind to specific sequences within genomic DNA and modulate the expression of downstream genes. This study focused on KojR, a transcription factor involved in the metabolism of kojic acid, which is an organic acid synthesize...

Full description

Bibliographic Details
Main Authors: Tomoka Mizutani, Hiroya Oka, Riko Goto, Ryoga Tsurigami, Jun-ichi Maruyama, Motoyuki Shimizu, Masashi Kato, Hideo Nakano, Takaaki Kojima
Format: Article
Language:English
Published: MDPI AG 2024-01-01
Series:Journal of Fungi
Subjects:
Online Access:https://www.mdpi.com/2309-608X/10/2/113
Description
Summary:DNA-binding transcription factors are broadly characterized as proteins that bind to specific sequences within genomic DNA and modulate the expression of downstream genes. This study focused on KojR, a transcription factor involved in the metabolism of kojic acid, which is an organic acid synthesized in <i>Aspergillus oryzae</i> and is known for its tyrosinase-inhibitory properties. However, the regulatory mechanism underlying KojR-mediated kojic acid synthesis remains unclear. Hence, we aimed to obtain a comprehensive identification of KojR-associated genes using genomic systematic evolution of ligands by exponential enrichment with high-throughput DNA sequencing (gSELEX-Seq) and RNA-Seq. During the genome-wide exploration of KojR-binding sites via gSELEX-Seq and identification of KojR-dependent differentially expressed genes (DEGs) using RNA-Seq, we confirmed that KojR preferentially binds to 5′-CGGCTAATGCGG-3′, and KojR directly regulates <i>kojT</i>, as was previously reported. We also observed that <i>kojA</i> expression, which may be controlled by KojR, was significantly reduced in a <i>ΔkojR</i> strain. Notably, no binding of KojR to the <i>kojA</i> promoter region was detected. Furthermore, certain KojR-dependent DEGs identified in the present study were associated with enzymes implicated in the carbon metabolic pathway of <i>A. oryzae</i>. This strongly indicates that KojR plays a central role in carbon metabolism in <i>A. oryzae</i>.
ISSN:2309-608X