Cell-Penetrating Peptide-Mediated Protein Uptake in Cyanobacteria


Cyanobacteria are photosynthetic bacteria that have played important roles in the development of the Earth and its atmosphere. Accordingly, novel experimental techniques for modifying their regulation and function are of great interest. Cell- penetrating peptides (CPPs) have attracted scientists' attention in recent decades, because they can overcome the hydrophobic plasma membrane barrier and enter cells directly. This phenomenon is known as protein transduction. In this study, we demonstrate that one CPP, the nona-arginine (R9) peptide, is able to deliver noncovalently associated green fluorescent protein (GFP) into Synechococcus elongatus PCC 7942 cyanobacteria. Reduction of GFP internalization by physical and pharmacological inhibitors demonstrated that uptake of uncomplexed GFP by cyanobacteria is mediated by classical endocytosis. CPP-mediated protein transduction of R9/GFP complexes was inhibited by treatment with N-ethylmaleimide (NEM), and macropinocytic inhibitors diminished CPP-mediated protein transduction of R9/GFP complexes in either the absence or presence of NEM. These two lines of evidence suggest that the major mechanism for CPP-mediated protein transduction is macropinocytosis, and classical endocytosis plays a minor role. Collectively, our CPP investigations offer the insight of the understanding of protein import in cyanobacteria.


Biological Sciences

International Standard Book Number (ISBN)

978-1-6346-3142-6; 978-1-6147-0925-1

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Book - Chapter

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© 2014 Nova Science Publishers, All rights reserved.

Publication Date

01 Jan 2014

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