Liposome Membrane Itself Can Affect Gene Expression in the Escherichia coli Cell-Free Translation System

Abstract

A possible role of a model biomembrane, liposome, in gene expression was investigated by using the cell-free translation system. A reporter protein, green fluorescence protein (GFP), was expressed in vitro with and without liposome prepared with 1-palmitoyl-2-oleoyl- sn-glycero-3-phosphatidyl chorine (POPC) and cholesterol (Ch) (5.7 mM lipid concentration). In the presence of POPC/Ch liposome, the fluorescence intensity of produced GFP was found to be 1.67 times higher than that in the control after 18 h of expression. The results of the SDS-PAGE analysis also show the above promotion effect of the liposome on the net expression of the GFP gene (1.58 times more). The amounts of mRNA were found to be promoted to 1.29 times higher than those in the control. The differences among mRNA, net expression of the GFP gene, and GFP fluorescence indicate that the enhanced GFP expression in the presence of POPC/Ch liposome could primarily affect the transcription and translation of the GFP gene among the possible steps of gene expression. The variation of in vitro gene expression with various liposomes also shows that the biomembrane could act as a modulator to split the genotype and phenotype in a biological cell.

Use Liposome as a Designable Platform for Molecular Recognition ~ from “Statistical Separation” to “Recognitive Separation” ~

“…"raft" domains) in cells has attracted much attention because of its implications for membrane-related processes, including bacterial and viral infections and signal transductions [22]. Recent studies have also revealed that the lipid membranes can activate the biomacromolecules and regulate their functions [6][7][8][9][39][40]. Liposomes have been intensely studied as a biomimetic environment of lipid bilayers.…”

“…A liposome membrane is effective in its use as a platform to perform the above purpose because it looks after the fundamental characteristics of a conventional extraction system and the recognition surface of the biomolecule ( Figure 1). In practice, there are many reports on the possible role of a liposome membrane to recognize various molecules , such as asymmetric recognition [56-57], metal affinity [4], peptide recognition [7,58], enzyme-like function [8,59], RNA recognition [6,42,48], and others [9,28] (Figure 8). membrane modules [61], and hydrogel immobilization of the liposomes at high concentration ( Figure 9) [62].…”

“…There are some examples of the ordered structure, created on the liposome membrane through the control of its combined interactions with the target molecules [6][7][8][9]. It is rational to use the membrane surface of a liposome membrane system as a platform for the recognition of biomolecules to create a new order on its surface.…”

Membranomics Research on Interactions between Liposome Membranes with Membrane Chip Analysis

“…On the other hand, the antioxidative activity 4 ～ 6) or gene expression system 3) have been well constructed on liposome membrane, which is called as LIPOzyme (liposome + enzyme). The previous reports on the LIPOzyme have indicated that the lipid composition and the phase state of lipid membrane, such as liquid-ordered (lo) phase, liquid-disordered (ld) phase and their mixture (ld + lo) phase, could control their function 5) .…”

Cationic Liposome Inhibits Gene Expression in an E.coliCell–Free Translation System

“…It has recently been reported that the liposome itself can affect the protein expression of the GFP gene 10) .…”