Human Z α1-antitrypsin accumulates intracellularly and stimulates lysosomal activity when synthesised in the Xenopus oocyte

AbstractMicroinjection of human liver mRNA from a patient homozygous for α1-antitrypsin deficiency (PiZZ) into Xenopus oocytes led to a 2–10-fold increase in lysosomal activity. Stimulation of lysosomal activity was not observed when mRNA from a normal human liver (α1-antitrypsin PiMM), or water was injected into the oocyte. This lysosomal activity was oocyte derived and was not due to translation products of the human liver mRNA. Thus a protein that accumulates intracellularly in the secretory pathway is capable of stimulating lysosomal activity