NEU4

NEU4 stands for neuraminidase 4, a member of the sialidase/neuraminidase family that removes sialic acid residues from glycoconjugates. In humans, NEU4 is one of four neuraminidase genes (NEU1–NEU4). The encoded enzyme belongs to glycoside hydrolase family 33 and catalyzes the hydrolysis of sialic acid residues on glycoproteins and glycolipids, thereby modulating the sialylation status of cell surfaces and secreted molecules.

NEU4 exists in multiple isoforms produced by alternative splicing, commonly referred to as NEU4-1 and NEU4-2. These isoforms show distinct subcellular localizations, with NEU4 activity reported in lysosomes and, in some contexts, mitochondria or other compartments.

Expression of NEU4 has been detected in various tissues; studies have reported its presence in neural tissue and other organ systems, indicating widespread but differential expression.

Physiological roles attributed to NEU4 include remodeling of glycans on glycoproteins and glycolipids, regulation of receptor signaling, cell adhesion, and apoptosis in some models. In disease contexts, altered NEU4 activity or expression has been observed in certain cancers and in neural and inflammatory disorders, though precise mechanisms are still under investigation.

NEU4 enzymes are studied in biomedical research to understand sialic acid biology and to explore potential therapeutic modulation of glycan structures.