In the field of
molecular biology, ''trans''-acting (''trans''-regulatory, ''trans''-regulation), in general, means "acting from a different molecule" (''i.e.'',
intermolecular). It may be considered the opposite of
''cis''-acting (''cis''-regulatory, ''cis''-regulation), which, in general, means "acting from the same molecule" (''i.e.'',
intramolecular).
In the context of
transcription regulation, a ''trans''-acting factor is usually a regulatory
protein that binds to
DNA. The binding of a ''trans''-acting factor to a ''cis''-regulatory element in
DNA can cause changes in transcriptional expression levels.
microRNAs or other diffusible molecules are also examples of ''trans''-acting factors that can regulate target sequences.
The ''trans''-acting gene may be on a different
chromosome to the target gene, but the activity is via the intermediary protein or RNA that it encodes.
''Cis''-acting elements, on the other hand, do not code for protein or RNA. Both the ''trans''-acting gene and the protein/RNA that it encodes are said to "act in ''trans''" on the target gene.
See also
*
Trans-regulatory element
*
Transactivation
*
Transrepression
References
Genetics terms
Molecular biology
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