Light-inducible carotenoid production controlled by a MarR-type regulator in Corynebacterium glutamicum

• Published in: Scientific reports Vol. 9; no. 1; pp. 13136 - 15
• Main Authors: Sumi, Satoru, Suzuki, Yuto, Matsuki, Tetsuro, Yamamoto, Takahiro, Tsuruta, Yudai, Mise, Kou, Kawamura, Takuya, Ito, Yusuke, Shimada, Yuka, Watanabe, Erika, Watanabe, Shoko, Toriyabe, Minami, Takano (Shiratori), Hatsumi, Ueda, Kenji, Takano, Hideaki
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 11.09.2019; Nature Publishing Group
• Subjects: 45/41; 45/90; 631/326/325/1506; 631/326/41/2482; Amino Acid Sequence; Amino acids; Bacteria; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Base Sequence; Biosynthesis; Carotenoids; Carotenoids - metabolism; Corynebacterium glutamicum; Corynebacterium glutamicum - genetics; Corynebacterium glutamicum - metabolism; DNA-directed RNA polymerase; Gene Expression Regulation, Bacterial - radiation effects; Genomes; Humanities and Social Sciences; Light; multidisciplinary; Multigene Family - genetics; Oxidants; Phototrophic bacteria; Promoter Regions, Genetic - genetics; Reverse Transcriptase Polymerase Chain Reaction; RNA polymerase; Science; Science (multidisciplinary); Transcription; Transcription Initiation Site; Transcription, Genetic - radiation effects
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-019-49384-7

Carotenoid production in some non-phototropic bacteria occurs in a light-dependent manner to protect cells from photo-oxidants. Knowledge regarding the transcriptional regulator involved in the light-dependent production of carotenoids of non-phototrophic bacteria has been mainly confined to coenzyme B 12 -based photo-sensitive regulator CarH/LitR family proteins belonging to a MerR family transcriptional regulator. In this study, we found that bacteria belonging to Micrococcales and Corynebacteriales exhibit light-dependent carotenoid-like pigment production including an amino acid-producer Corynebacterium glutamicum AJ1511. CrtR is a putative MarR family transcriptional regulator located in the divergent region of a carotenoid biosynthesis gene cluster in the genome of those bacteria. A null mutant for crtR of C . glutamicum AJ1511 exhibited constitutive production of carotenoids independent of light. A complemented strain of the crtR mutant produced carotenoids in a light-dependent manner. Transcriptional analysis revealed that the expression of carotenoid biosynthesis genes is regulated in a light-dependent manner in the wild type, while the transcription was upregulated in the crtR mutant irrespective of light. In vitro experiments demonstrated that a recombinant CrtR protein binds to the specific sequences within the intergenic region of crtR and crtE , which corresponds to −58 to −7 for crtE , and +26 to −28 for crtR with respect to the transcriptional start site, and serves as a repressor for crtE transcription directed by RNA polymerase containing SigA. Taken together, the results indicate that CrtR light-dependently controls the expression of the carotenoid gene cluster in C . glutamicum and probably closely related Actinobacteria .