Partnereiwitten

Partnereiwitten refers to proteins that bind to other proteins to form functional complexes. Such interactions are central to nearly all cellular processes and can determine the location, activity, stability, and assembly of protein networks. Partner associations are usually non-covalent, relying on complementary surfaces and interactions such as hydrogen bonds, ionic contacts, and hydrophobic effects, though covalent modifications can reinforce binding or create new binding sites.

Partner proteins act as scaffolds or adaptors that organize signaling networks, bring enzymes into proximity, or recruit cofactors. Others function as chaperones, ensuring proper folding or preventing aggregation. Some modulate activity allosterically, or regulate subcellular localization and turnover. In transcription and chromatin biology, coactivators and corepressors are partner proteins of DNA-binding factors; in metabolism, enzyme complexes form metabolons via partner interactions.

Identification and study of partner proteins employ approaches such as yeast two-hybrid screening, co-immunoprecipitation, pull-down assays, cross-linking coupled to mass spectrometry, and structural methods like X-ray crystallography and cryo-electron microscopy. Well-known examples include 14-3-3 proteins, which act as adapters for many phosphorylated partners; SH2/SH3 domain–containing adaptors; and scaffold proteins that organize signaling assemblies. Misregulation of partner interactions can contribute to disease, and disrupting specific interactions is an area of therapeutic interest.