Latexin, also known as endogenous carboxypeptidase inhibitor, tissue carboxypeptidase inhibitor, TCI, ECI and LXN, is a cytoplasm protein which belongs to the protease inhibitor I47 (latexin) family. It is highly expressed in heart, prostate, ovary, kidney, pancreas, and colon. Latexin / LXN is the only known endogenous specific inhibitor of zinc-dependent metallocarboxypeptidases (MCPs) present in mammalians so far. Latexin is originally identified as a molecular marker for the regional specification of the neocortex in development in rats. The 222 amino acid latexin in human shows different expression distribution with high levels in heart, prostate, ovary, kidney, pancreas, and colon, but only moderate or low levels in other tissues including brain. Latexin is also expressed at high levels and is inducible in macrophages in concert with other protease inhibitors and potential protease targets, and thus is suggested to play a role in inflammation and innate immunity pathways. Despite of the non-detectable sequence similarity with plant and parasite inhibitors, Latexin is related to a human putative tumor suppressor protein, TIG1. In addition, Latexin is also implicated in Alzheimer's disease.
