Most previous studies on inhibitors of lysosomal protein breakdown have been performed on isolated or cultured cells or on perfused organs. We have tested various inhibitors of proteolysis on lysosomes isolated from livers of rats injected with [‘4C]leucine 15 min (short labeling time) and 16 h (long labeling time) before killing. Intact lysosomes were incubated with different inhibitors (leu...

Lamellar bodies and lysosomes from the lungs of rabbits were examined for the presence of 24 hydrolytic enzymes. All hydrolases detectable in lysosomes were also found in lamellar bodies. Hydrolase activities in lamellar bodies were not due to contamination with lysosomes as shown by isopycnic centrifugation of the subcellular organelles on continuous density sucrose gradients. Lysosomal prepar...

Iron is an essential transition metal for its involvement in several crucial biological functions, the most notable being oxygen storage and transport. Due to high reactivity potential toxicity, intracellular extracellular iron levels must be tightly regulated. This achieved through transport systems that mediate cellular uptake efflux both at level of plasma membrane on membranes lysosomes, en...

I f an intracellular parasite is too successful at hiding itself, it can end up starving. Toxoplasma gondii gets around this potential problem by munching nutrient-fi lled host lysosomes, say Isabelle Coppens and colleagues. T. gondii has an extraordinary mechanism for creating a parasitophorous vacuole (PV) around itself—it motors into a host mammalian cell and uses a ring-shaped moving juncti...

Secretory lysosomes are lysosomes which are capable of undergoing regulated secretion in response to external stimuli. Many cells of the immune system use secretory lysosomes to release proteins involved in their specialised effector mechanisms. Precisely how lysosomal secretion is regulated in each of these cell types is now the study of much research as these mechanisms control the ability of...

Late endocytic organelles including lysosomes are highly dynamic acidic organelles. Late endosomes and lysosomes directly fuse for content mixing to form hybrid organelles, from which lysosomes are reformed. It is not fully understood how these processes are regulated and maintained. Here we show that the Caenorhabditis elegans ARL-8 GTPase is localized primarily to lysosomes and involved in la...

SUMMARY It has been demonstrated that solid hepatoma lysosomes lack hyaluronidase activity, whereas normal rat liver lyso somes contain a high level of this enzyme. This result was also found with lysosomes from an ascites hepatoma, Walker carcinoma 256, and virally transformed BHK cells. In contrast, 0-yV-acetylglucosaminidase activity was shown to be present in lysosomes from tumor cells, alt...

It has been demonstrated that solid hepatoma lysosomes lack hyaluronidase activity, whereas normal rat liver lyso somes contain a high level of this enzyme. This result was also found with lysosomes from an ascites hepatoma, Walker carcinoma 256, and virally transformed BHK cells. In contrast, 0-yV-acetylglucosaminidase activity was shown to be present in lysosomes from tumor cells, although it...

Lysosomes are classically viewed as vesicular structures to which cargos are delivered for degradation. Here, we identify a network of dynamic, tubular lysosomes that extends throughout Drosophila muscle, in vivo. Live imaging reveals that autophagosomes merge with tubular lysosomes and that lysosomal membranes undergo extension, retraction, fusion and fission. The dynamics and integrity of thi...

nieman-pick disease type c is a rare, autosomal recessive, neurometabolic disorder associated with the accumulation of unesterified cholesterol in lysosomes and late endosomes. because of multiple organ involvement and wide range of clinical manifestations, these patients will demand multiple diagnostic and therapeutic procedures requiring anesthesia. sincepathogenesis of this disease is still ...