Overexpression system for recombinant RNA in Corynebacterium glutamicum using a strong promoter derived from corynephage BFK20.
J Biosci Bioeng 2019;
128:255-263. [PMID:
31076339 DOI:
10.1016/j.jbiosc.2019.03.003]
[Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 02/20/2019] [Accepted: 03/07/2019] [Indexed: 01/16/2023]
Abstract
In recent years, it has been shown that recombinant RNA molecules have a great potential in mRNA therapy and as novel agricultural pesticides. We developed a fundamental system for efficient production of target RNA molecules in Corynebacterium glutamicum, composed of a strong promoter named F1 and a terminator derived from corynephage BFK20 in a high-copy number plasmid vector. As a target model RNA for overexpression, we designed and used an RNA molecule [designated U1A*-RNA, ∼160 nucleotides (nt) long] containing a stem/loop II (SL-II, hairpin-II) structure from U1 small nuclear RNA (snRNA), which binds to U1A protein, forming a U1 sn-ribonucleoprotein, which is essential in the pre-mRNA splicing process. C. glutamicum strains harboring the U1A*-RNA expression plasmid were cultured and the total RNA was analyzed. We observed prominent expression of RNA corresponding to the U1A*-RNA transcript along with lower expression of a 3'-region-truncated form of the transcript (∼110 nt) in an rnc (encoding RNase III)-deficient strain. We also found that the produced U1A*-RNA bound to the U1A RNA-binding domain protein, which was separately prepared with C. glutamicum. In a batch cultivation using a fermentor, the total accumulated amount of the target RNA reached about 300 mg/L by 24 h. Thus, our results indicated that our system can serve as an efficient platform for large-scale preparation of an RNA of interest.
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