Mona Sohrabi - Department of Life ScienceEngineering, Faculty of New Sciences and Technologies, University of Tehran, Tehran, Iran
Zahra Hajihassan - Department of Life ScienceEngineering, Faculty of New Sciences and Technologies, University of Tehran, Tehran, Iran
Masoumeh Rajabibazl - Department of Clinical Biochemistry, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Faezeh Sarayloo - Department of Life ScienceEngineering, Faculty of New Sciences and Technologies, University of Tehran, Tehran, Iran

Among the wide variety of expression systems such as eukaryotic and prokaryotic hosts used for expression and production of recombinant proteins, there are some difficulties for accessing an optimum yield of a functional recombinant protein. Drawbacks such as the lack of post-translational modification machinery in prokaryotes drew scientists’ attention to eukaryotic expression system. However, the costly and long recovery process using eukaryotic hosts are the main reasons why bacteria are still remain as favorite hosts. This review, mainly discusses strategies for production of recombinant proteins in soluble form in the cytoplasm of E.coli. Besides, in order to avoid the reducing environment of cytoplasm and achieve a correctly folded target protein we explain the extracellular production of recombinant proteins and three different secretion systems of E.coli as a great opportunity to maintain the proper folding process in the periplasmic space or the secretion to the culture medium.

Escherichia coli, Recombinant Protein, Cytoplasmic Soluble Protein, Extracellular Production, Secretary Pathways