Development of Lactococcus lactis encoding fluorescent proteins, GFP, mCherry and iRFP regulated by the nisin-controlled gene expression system.
Fluorescent proteins are useful reporter molecules for a variety of biological systems. We present an alternative strategy for cloning reporter genes that are regulated by the nisin-controlled gene expression (NICE) system. Lactoccocus lactis was genetically engineered to express green fluorescent protein (GFP), mCherry or near-infrared fluorescent protein (iRFP). The reporter gene sequences were optimized to be expressed by L. lactis using inducible promoter pNis within the pNZ8048 vector. Expression of constructions that carry mCherry or GFP was observed by fluorescence microscopy 2 h after induction with nisin. Expression of iRFP was evaluated at 700 nm using an infrared scanner; cultures induced for 6 h showed greater iRFP expression than non-induced cultures or those expressing GFP. We demonstrated that L. lactis can express efficiently GFP, mCherry and iRFP fluorescent proteins using an inducible expression system. These strains will be useful for live cell imaging studies in vitro or for imaging studies in vivo in the case of iRFP.
a The Hiram C Polk Jr., MD, Department of Surgery , University of Louisville School of Medicine , Louisville , Kentucky.|b Department of Histology , School of Medicine, Autonomous University of Nuevo León , Monterrey , NL , México.
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E
Martinez-Jaramillo
b Department of Histology , School of Medicine, Autonomous University of Nuevo León , Monterrey , NL , México.
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R
Garza-Morales
b Department of Histology , School of Medicine, Autonomous University of Nuevo León , Monterrey , NL , México.
M J
MJ
Loera-Arias
b Department of Histology , School of Medicine, Autonomous University of Nuevo León , Monterrey , NL , México.
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Saucedo-Cardenas
b Department of Histology , School of Medicine, Autonomous University of Nuevo León , Monterrey , NL , México.
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Montes-de-Oca-Luna
c Department of Medicine , James Graham Brown Cancer Center, University of Louisville School of Medicine , Louisville , Kentucky.
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McNally
a The Hiram C Polk Jr., MD, Department of Surgery , University of Louisville School of Medicine , Louisville , Kentucky.
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JG
Gomez-Gutierrez
D003001:Cloning, Molecular / Q000379:methods*; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects*; D049452:Green Fluorescent Proteins / Q000235:genetics*; D013294:Lactococcus lactis / Q000235:genetics*; D008164:Luminescent Proteins / Q000235:genetics*; D008856:Microscopy, Fluorescence; D009561:Nisin / Q000494:pharmacology*; D010957:Plasmids / Q000235:genetics; D013055:Spectrophotometry, Infrared; D000097573:Red Fluorescent Protein
D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins; D009561:Nisin; D000097573:Red Fluorescent Protein
GFP; Lactococcus lactis; NICE; fluorescent proteins; iRFP; mCherry; nisin-controlled gene expression; plasmids