Omics Analysis Reveals the Mechanism of Enhanced Recombinant Protein Production Under Simulated Microgravity

Abstract

Simulated microgravity (SMG) is regarded as a suitable environment to produce recombinant proteins. This study showed that β-glucuronidase expressing Escherichia coli had higher productivity of recombinant protein and higher plasmid copy number under SMG compared with the normal gravity condition. The cellular changes were analyzed at both transcriptomic and proteomic levels. The upregulation of a group of ribosome/RNA polymerase genes and a cluster of genes involving energy metabolism at transcriptomic level stood out for improved production of recombinant protein under SMG. The protein folding modulators such as chaperones were upregulated at proteomic level, which could be a result of the increased activity of protein synthesis and can help recombinant protein production. Protein export was also strengthened, which was revealed at both transcriptomic and proteomic levels. The results demonstrated that SMG is a favorable environment for recombinant protein production arousing the upregulation of protein synthesis, protein folding, and protein export.

Enhanced Recombinant Protein Production Under Special Environmental Stress

“…A recent research revealed the mechanism causing enhanced heterologous β-glucuronidase production in E. coli under simulated microgravity by multi-omics. Its transcriptome and proteomic analysis demonstrated that ribosome function and carbon metabolism were the two main points affecting the differential expression genes response to microgravity (Huangfu et al, 2020). As discussed above, hypoxia conditions can benefit recombinant protein production in yeasts.…”

“…Some researchers have proved that the microgravity condition is beneficial for microbial growth and their capacities to express recombinant proteins (Huang et al, 2012). Because it is difficult to attain the actual microgravity conditions in spaceflight due to the high cost and long duration of spaceflight, The specialized ground-based bioreactors were designed to simulate the weightlessness condition which was characterized by low sedimentation, low shear stress, and low turbulence (Huangfu et al, 2020). To achieve this, the equipment employed for providing microgravity should permit cell growth in suspension and minimize the fluid shear levels encountered by cells.…”

“…Some researchers analyze the changes of host cells at both transcriptomic and proteomic levels under the microgravity condition. The most significant results include the upregulation of ribosome/RNA polymerase genes and genes involved in energy metabolism and protein folding (Klaus, 1998;Demain and Fang, 2001;Johanson et al, 2002;Vukanti et al, 2008;Van Mulders et al, 2011;Kim et al, 2014;Huangfu et al, 2020). Therefore, the benefits of SMG on host cells can be summarized as follows.…”

Designing next generation recombinant protein expression platforms by modulating the cellular stress response in Escherichia coli

“…A much better picture of cellular dynamics has emerged by transcriptomic profiling of post induction cultures [4,9,[12][13][14]. These have been combined with proteomic and metabolomics studies to show that increased acetate production, growth retardation, increased demand for maintenance energy, the down-regulation of amino acid biosynthesis, poorer substrate uptake and change in the pattern of oxygen utilization are all effects of cellular reprogramming due to stress [15][16][17][18][19]. This reprogramming works to reduce the rate of protein synthesis and hence many researchers have supplemented the expression of key down-regulated genes such as those involved in ATP synthesis, energy generation, substrate uptake and obtained significant increase in productivity [18,[20][21][22].…”

Designing next generation recombinant protein expression platforms by modulating the cellular stress response in Escherichia coli

“…A much better picture of cellular dynamics has emerged by transcriptomic pro ling of post induction cultures [4,9,[12][13][14]. These have been combined with proteomic and metabolomics studies to show that increased acetate production, growth retardation, increased demand for maintenance energy, the down-regulation of amino acid biosynthesis, poorer substrate uptake and change in the pattern of oxygen utilization are all effects of cellular reprogramming due to stress [15][16][17][18][19]. This reprogramming works to reduce the rate of protein synthesis and hence many researchers have supplemented the expression of key down-regulated genes such as those involved in ATP synthesis, energy generation, substrate uptake and obtained signi cant increase in productivity [18,[20][21][22].…”