Mislocalize

Mislocalize is a verb meaning to cause or result in an object, molecule, or component being located in an incorrect place within a cell or organism. Mislocalization is the state or process of being located in the wrong place. In cellular biology, proper localization is essential for function; mislocalization can arise from defective signal sequences, mutations in targeting motifs such as nuclear localization signals or mitochondrial targeting sequences, or from disruptions in trafficking pathways, chaperone activity, or post-translational modifications. Consequences include loss of function, gain of aberrant function, and impaired cellular organization, potentially contributing to disease.

In eukaryotic cells, proteins typically have signals that direct them to the nucleus, mitochondria, endoplasmic reticulum, membranes, or cytosol. When these signals are altered or recognition by transport machinery is compromised, the protein may accumulate in the wrong compartment. Detection relies on imaging methods like fluorescence microscopy, immunostaining, or subcellular fractionation.

Clinically, mislocalization has been observed in several diseases. For example, tumor suppressor p53 mislocalization from the nucleus to the cytoplasm can reduce transcriptional activity and promote tumorigenesis. In neurodegenerative disorders, mislocalization of proteins such as tau from axons to somatodendritic regions, or alpha-synuclein from presynaptic terminals to cell bodies, is associated with cellular dysfunction. Mislocalization can also reflect mutations that alter protein trafficking, or stresses that disrupt normal cellular architecture.

See also: protein trafficking, localization signal, subcellular localization.