An expression cassette is a distinct component of
vector DNA consisting of a
gene
In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...
and regulatory sequence to be expressed by a
transfected cell. In each successful transformation, the expression cassette directs the cell's machinery to make
RNA
Ribonucleic acid (RNA) is a polymeric molecule essential in various biological roles in coding, decoding, regulation and expression of genes. RNA and deoxyribonucleic acid ( DNA) are nucleic acids. Along with lipids, proteins, and carbohydra ...
and protein(s). Some expression cassettes are designed for modular cloning of protein-encoding sequences so that the same cassette can easily be altered to make different proteins.
An expression cassette is composed of one or more genes and the sequences controlling their
expression. An expression cassette comprises three components: a
promoter sequence, an
open reading frame, and a 3' untranslated region that, in eukaryotes, usually contains a
polyadenylation
Polyadenylation is the addition of a poly(A) tail to an RNA transcript, typically a messenger RNA (mRNA). The poly(A) tail consists of multiple adenosine monophosphates; in other words, it is a stretch of RNA that has only adenine bases. In eu ...
site.
Different expression cassettes can be transfected into different organisms including bacteria, yeast, plants, and mammalian cells as long as the correct regulatory sequences are used.
See also
*
Expression vector
*
Gene cassette
References
DNA
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