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 and ...
and
protein biochemistry, heterologous expression means that a protein is experimentally put into a cell that does not normally make (i.e.,
express
Express or EXPRESS may refer to:
Arts, entertainment, and media Films
* '' Express: Aisle to Glory'', a 1998 comedy short film featuring Kal Penn
* '' The Express: The Ernie Davis Story'', a 2008 film starring Dennis Quaid
Music
* ''Express'' ...
) 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 synthesized from a single-stranded RNA (e.g., messenger RNA (mRNA) or microRNA (miRNA)) template in a reaction catalyzed by the enzyme reverse transcriptase. cDNA is often used to express a speci ...
) 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 is used to introduce a specific gene into a target cell, and can commandeer the cell's mechanism for ...
).
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 desc ...
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
In multicellular organisms, stem cells are undifferentiated or partially differentiated cells that can differentiate into various types of cells and proliferate indefinitely to produce more of the same stem cell. They are the earliest type o ...
, a heterologous transplant refers to cells from a mixed population of donor cells. This is in contrast to an
autologous
Autotransplantation is the transplantation of organs, tissues, or even particular proteins from one part of the body to another in the same person ('' auto-'' meaning "self" in Greek).
The autologous tissue (also called autogenous, autogene ...
transplant where the cells are derived from the same individual or an
allogenic
In ecology, allogenic succession is succession driven by the abiotic components of an ecosystem. In contrast, autogenic succession is driven by the biotic components of the ecosystem. An allogenic succession can be brought about in a number of ways ...
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
Autotransplantation is the transplantation of organs, tissues, or even particular proteins from one part of the body to another in the same person ('' auto-'' meaning "self" in Greek).
The autologous tissue (also called autogenous, autogene ...
or
allogenic
In ecology, allogenic succession is succession driven by the abiotic components of an ecosystem. In contrast, autogenic succession is driven by the biotic components of the ecosystem. An allogenic succession can be brought about in a number of ways ...
cellular therapies.
Structural biology
In
structural biology
Structural biology is a field that is many centuries old which, and as defined by the Journal of Structural Biology, deals with structural analysis of living material (formed, composed of, and/or maintained and refined by living cells) at every le ...
, a heterologous association is a binding mode between the
protomer
In structural biology, a protomer is the structural unit of an oligomeric protein. It is the smallest unit composed of at least two different protein chains that form a larger hetero-oligomer by association of two or more copies of this unit.
The ...
s 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
Autotransplantation is the transplantation of organs, tissues, or even particular proteins from one part of the body to another in the same person ('' auto-'' meaning "self" in Greek).
The autologous tissue (also called autogenous, autogene ...
*
Homologous
**
Homology (biology)
In biology, homology is similarity due to shared ancestry between a pair of structures or genes in different taxa. A common example of homologous structures is the forelimbs of vertebrates, where the wings of bats and birds, the arms of pri ...
*
Heterogeneous
Homogeneity and heterogeneity are concepts often used in the sciences and statistics relating to the uniformity of a substance or organism. A material or image that is homogeneous is uniform in composition or character (i.e. color, shape, siz ...
References
Protein structure
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