Richard J. Stockert

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Transport of macromolecules into the cell by receptor-mediated endocytosis follows a complex series of intracellular transfers, passing through distinct environments. The asialoglycoprotein receptor is a prototype of the class of receptors that constitutively enters cells via coated pits and delivers ligand to these intracellular compartments. In addition(More)
In a recent study (Goltz, J.S., Wolkoff, A.W., Novikoff, P.M., Stockert, R.J., and Satir, P. (1992) Proc. Natl. Acad. Sci. U.S.A. 89, 7026-7030), we found that ligand- and receptor-containing endocytic vesicles bind to endogenous microtubules in vitro after 60 min of receptor-mediated endocytosis of asialo-orosomucoid. In the presence of ATP,(More)
As a putative mechanism of hepatitis B virus (HBV) uptake into hepatocytes the interaction between HBV and the hepatic, human-derived asialoglycoprotein receptor (ASGPR) was investigated. Sera from patients with different variations of hepatitis B surface antigen-(HBsAg) positive chronic hepatitis, HBV particles isolated from HBV carriers with high-titre(More)
Early endocytic vesicles loaded with Texas Red asialoorosomucoid were prepared from mouse liver. These vesicles bound to microtubules in vitro, and upon ATP addition, they moved bidirectionally, frequently undergoing fission into two daughter vesicles. There was no effect of vanadate (inhibitor of dynein) on motility, whereas 5'-adenylylimido-diphosphate(More)
We studied the mechanisms by which excess copper exerts, and zinc mitigates, toxic effects on HepG2 cells. Survival and cell growth were reduced in media containing greater than 500 microM copper chloride for 48 h; LD50 was 750 microM. At 1,000 microM copper for 1 h, there was a general reduction of protein synthesis, and no recognizable changes in cellular(More)
A previously isolated endocytic trafficking mutant (TRF1) isolated from HuH-7 cells is defective in the distribution of subpopulations of cell-surface receptors for asialoorosomucoid (asialoglycoprotein receptor (ASGR)), transferrin, and mannose-terminating glycoproteins. The pleiotropic phenotype of TRF1 also includes an increased sensitivity to(More)
We developed and characterized a coculture system composed of a fat-storing cell clone (CFSC-2G) and freshly isolated hepatocytes that can reproduce in vitro some of the physical and functional relationships observed in vivo. Hepatocytes in the coculture are polarized, are smaller in size than hepatocytes plated on plastic, maintain a cuboidal shape, and(More)
Mutant human hepatoblastoma cell lines resistant to copper toxicity were isolated from mutagenized HuH7. Two copper resistant cell lines (CuR), CuR 23 and CuR 27, had reduced basal expression of metallothionein (MT) messenger RNA (mRNA) and exhibited minimal or no increase in resistance to cadmium or zinc toxicity. Copper uptake, efflux of newly transported(More)
Viral vectors and protein carriers utilizing asialoglycoprotein receptor (ASGR)-mediated endocytosis are being developed to transfer genes for the correction of bilirubin-UDP-glucuronosyltransferase (bilirubin-UGT) deficiency. Ex vivo evaluation of these gene transfer vectors would be facilitated by a cell system that lacks bilirubin-UGT, but expresses(More)