Transregulering

Transregulering, or trans-regulation, is a term used in molecular biology to describe regulatory interactions in which a regulatory molecule influences the expression of a gene that is not physically linked to the regulator's own genetic locus. The regulator can be a transcription factor, a noncoding RNA, or another diffusible molecule produced by a gene elsewhere in the genome. Because these regulators act in trans, they can affect many target genes across the genome, contributing to coordinated gene expression programs.

Mechanisms of trans-regulation include the action of transcription factors that bind to promoters or distal enhancers of target genes, thereby increasing or decreasing transcription. Noncoding RNAs, such as microRNAs or small interfering RNAs, can act in trans by binding to messenger RNases from distant genes to modulate stability or translation. Chromatin modifiers or signaling molecules that influence chromatin state or transcriptional machinery at multiple genomic locations also participate in trans-regulatory networks.

Trans-regulation is contrasted with cis-regulation, where regulatory elements such as promoters or enhancers control the expression of the adjacent gene. In practice, most gene expression is governed by a combination of cis and trans interactions, forming complex regulatory networks. The concept is central to studies of gene expression variation, including trans-eQTL analysis, which aims to identify regulatory loci that affect the expression of distant genes.

Understanding trans-regulation has implications for development, physiology, and disease, as perturbations in trans-regulatory factors can have widespread effects. Researchers study trans-regulatory networks using approaches such as allele-specific expression, reporter assays, and chromosome conformation capture to map distal regulatory interactions.