title: UV-A-induced expression of GroEL in the UV-A-resistant marine cyanobacterium Oscillatoria sp. NKBG 091600.
abstract: The authors have examined the response to UV-A irradiation of the UV-A-resistant marine cyanobacterium Oscillatoria sp. NKBG 091600, which produces the UV-A-absorbing compound biopterin glucoside. The expression of a 60 kDa protein was markedly induced at 500 min after UV-A irradiation. This protein was identified by N-terminal amino acid sequence analysis as GroEL. Northern blot analysis demonstrated that GroEL synthesis was controlled by UV-A at the transcriptional level. A CIRCE element and a putative SOS consensus sequence were found upstream of the groESL operon, overlapping two putative promoter sequences. Primer extension analysis revealed that groESL transcription in UV-A-induced cells starts from the proximal promoter overlapped by the SOS consensus sequence. This indicates that an SOS response regulation is instrumental in UV-A-induced GroEL expression of Oscillatoria sp. NKBG 091600. Furthermore, this UV-A-inducible GroEL may function to upregulate biopterin glucoside biosynthesis, thereby allowing growth under UV-A irradiation.
authors.forename: Akira
authors.initials: A
authors.lastname: Yamazawa
authors.forename: Haruko
authors.initials: H
authors.lastname: Takeyama
authors.forename: Daisuke
authors.initials: D
authors.lastname: Takeda
authors.forename: Tadashi
authors.initials: T
authors.lastname: Matsunaga
mesh_terms: D001483:Base Sequence; D015152:Blotting, Northern; D018834:Chaperonin 60 / Q000096:biosynthesis / Q000235:genetics* / Q000302:isolation & purification; D000458:Cyanobacteria / Q000235:genetics* / Q000254:growth & development / Q000528:radiation effects*; D004591:Electrophoresis, Polyacrylamide Gel; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D009876:Operon; D011836:Radiation Tolerance; D017422:Sequence Analysis, DNA; D014158:Transcription, Genetic; D014466:Ultraviolet Rays
chemical_list: D018834:Chaperonin 60