Trans-acting

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 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 element is usually a DNA sequence that contains a gene. This gene codes for a protein (or microRNA or other diffusible molecule) that will be used in the regulation of another target gene.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.