LOXLCH4

LOXLCH4 is an informal designation that is sometimes used to refer to the lysyl oxidase-like 4 gene on chromosome 4 in humans. The official gene symbol is LOXL4. LOXL4 belongs to the lysyl oxidase (LOX) family of copper-dependent amine oxidases that modify extracellular matrix components.

Function and biochemistry

LOXL4 catalyzes oxidative deamination of specific lysine residues in collagen and elastin, initiating cross-linking that strengthens and stabilizes the extracellular matrix (ECM). The enzyme is secreted as a pro-enzyme and becomes active after proteolytic processing. The catalytic reaction consumes molecular oxygen and yields hydrogen peroxide as a byproduct, generating reactive aldehydes that form covalent ECM cross-links. This activity contributes to ECM maturation, stiffness, and remodeling.

Expression and regulation

LOXL4 expression is broad but tissue- and context-dependent, with regulation at transcriptional and post-transcriptional levels. Signaling pathways such as TGF-β and hypoxia can influence LOXL4 expression and activity. Post-translational processing, including proteolytic activation, controls the generation of active enzyme.

Clinical and research relevance

In physiological contexts, LOXL4 participates in normal tissue development, wound healing, and repair through ECM remodeling. In pathology, members of the LOX family, including LOXL4, have been linked to fibrosis and cancer progression. They can promote invasive behavior by modifying the ECM and influencing signaling pathways related to epithelial-mesenchymal transition. Because of these roles, LOX/LOXL enzymes are explored as potential therapeutic targets for fibrotic diseases and metastasis, though effects are highly context-dependent and require careful consideration in therapeutic design.

Note: While LOXLCH4 is a usable informal reference, the authoritative name for the human gene is LOXL4.