What Is a Cell Expression System?

Cell Expression System

Cell expression systems are used in cellular research and in the commercial production of enzymes and therapeutics. In the simplest terms, cell expression systems are constructs encoded with DNA that can produce new proteins or RNA. This may be done inside or outside of a cell. The two main types of cell expression are gene expression and protein expression. Advancements in biotechnology like genetic engineering and cloning have made it possible to express and isolate proteins from bacteria, fungi, insects, and even mammals for research purposes.

Our understanding of gene expression and proteins are intertwined. The final structure of a protein is determined by the sequence of amino acids within it. Many proteins already have known functions within cells and are stored in databases. To discover the effects of an unknown protein, one can observe a cell that lacks it and then introduce the new protein. Studying the effects of proteins and RNA on cells helps researchers understand normal cell functions and can become the basis for new disease treatments.

Expression in Bacteria and Fungi

A great example of protein expression in a single-celled organism is Pichia pastoris expression. Pichia pastoris is a form of yeast, and it’s able to perform higher levels of eukaryotic protein modifications compared to many other single-celled organisms, such as bacteria. Pichia pastoris has been invaluable for the biotechnology industry as it’s able to easily produce heterologous proteins at a high expression level. In other words, Pichia can be used for mass protein production. It’s also useful for screening clones of other cells, and the FDA has issued GRAS (generally regarded as safe) status for many protein products created thanks to the P. Pastoris strain. This includes products both for food and pharmaceutical applications.

Bacteria are often used in the large-scale production of proteins as well, with E. coli being an especially popular choice since it already has multiple strains specializing in expression. The main reason bacteria cells are popular is because of the ease with which they can produce proteins, but they won’t be useful for all applications. For example, bacteria aren’t able to produce proteins complex enough for research in mammalian cells.

Expression in Insects

Insect cells are often used to produce high levels of recombinant proteins (clones of proteins created in an expression system), so long as the correct post-translational modifications are used. Insect expression allows for complex recombinant protein production that simply wouldn’t be possible using bacteria or yeast, but the downside is that cells used in this type of system will eventually become unable to produce more proteins. Effective production also requires delicate culture conditions.

Expression in Mammals

Naturally, mammalian cells are the ideal subjects for mass-producing proteins for research involving mammalian subjects, such as humans. Mammalian systems make it much easier compared to others to produce complex proteins that require multiple post-translation modifications. Various promoters can also be used to control when proteins are produced.

While mammalian systems have many undeniable advantages, they are challenging to use as they require much stricter conditions compared to any other system.

Managing Data Effectively

Any lab that engages in cell expression or the production of biopharmaceuticals is naturally going to have huge amounts of data to sort through and record. It’s also likely that there are multiple teams working who all need to ensure they’re sharing the same data, and that it’s always accurate and up to date. This is where a master data management (MDM) system comes in.

MDM systems ensure your master data (data subject to controls and analysis) is compiled within a single, consistent, and reliable source. This will help to both improve productivity and help you identify and act on insights faster than ever before