The term heterologous has several meanings in biology.
Gene expression
In
cell biology
Cell biology (also cellular biology or cytology) is a branch of biology that studies the structure, function, and behavior of cells. All living organisms are made of cells. A cell is the basic unit of life that is responsible for the living an ...
and
protein biochemistry, heterologous expression means that a protein is experimentally put into a cell that does not normally make (i.e.,
express
Express, The Expresss or EXPRESS may refer to:
Arts, entertainment and media Film
* ''Express: Aisle to Glory'', a 1998 comedy short film featuring Kal Penn
* ''The Express: The Ernie Davis Story'', a 2008 film starring Dennis Quaid
* The Expre ...
) that protein. Heterologous (meaning 'derived from a different organism') refers to the fact that often the transferred protein was initially cloned from or derived from a different cell type or a different species from the recipient.
Typically the protein itself is not transferred, but instead the 'correctly edited' genetic material coding for the protein (the complementary DNA or
cDNA
In genetics, complementary DNA (cDNA) is DNA that was reverse transcribed (via reverse transcriptase) from an RNA (e.g., messenger RNA or microRNA). cDNA exists in both single-stranded and double-stranded forms and in both natural and engin ...
) is added to the recipient cell. The genetic material that is transferred typically must be within a format that encourages the recipient cell to express the cDNA as a protein (i.e., it is put in an
expression vector
An expression vector, otherwise known as an expression construct, is usually a plasmid or virus designed for gene expression in cells. The vector (molecular biology), vector is used to introduce a specific gene into a target cell, and can command ...
).
Methods for transferring foreign genetic material into a recipient cell include
transfection
Transfection is the process of deliberately introducing naked or purified nucleic acids into eukaryotic cells. It may also refer to other methods and cell types, although other terms are often preferred: " transformation" is typically used to des ...
and
transduction. The choice of recipient cell type is often based on an experimental need to examine the protein's function in detail, and the most prevalent recipients, known as heterologous expression systems, are chosen usually because they are easy to transfer DNA into or because they allow for a simpler assessment of the protein's function.
Stem cells
In
stem cell biology, a heterologous transplant refers to cells from a mixed population of donor cells. This is in contrast to an
autologous transplant where the cells are derived from the same individual or an
allogenic transplant where the donor cells are HLA matched to the recipient. A heterologous source of therapeutic cells will have a much greater availability than either
autologous or
allogenic cellular therapies.
Structural biology
In
structural biology
Structural biology deals with structural analysis of living material (formed, composed of, and/or maintained and refined by living cells) at every level of organization.
Early structural biologists throughout the 19th and early 20th centuries we ...
, a heterologous association is a binding mode between the
protomers of a protein structure.
In a heterologous association, each protomer contributes a different set of residues to the binding interface. In contrast, two protomers form an isologous association when they contribute the same set of residues to the protomer-protomer interface.
See also
*
Autologous
*
Homologous
**
Homology (biology)
In biology, homology is similarity in anatomical structures or genes between organisms of different taxa due to shared ancestry, ''regardless'' of current functional differences. Evolutionary biology explains homologous structures as retained her ...
*
Heterogeneous
Homogeneity and heterogeneity are concepts relating to the uniformity of a substance, process or image. A homogeneous feature is uniform in composition or character (i.e., color, shape, size, weight, height, distribution, texture, language, i ...
References
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Protein structure