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Receptor recycling involves two endosome populations, peripheral early endosomes and perinuclear recycling endosomes. In polarized epithelial cells, either or both populations must be able to sort apical from basolateral proteins, returning each to its appropriate plasma membrane domain. However, neither the roles of early versus recycling endosomes in(More)
  • I Mellman
  • 1996
Endocytosis in eukaryotic cells is characterized by the continuous and regulated formation of prolific numbers of membrane vesicles at the plasma membrane. These vesicles come in several different varieties, ranging from the actin-dependent formation of phagosomes involved in particle uptake, to smaller clathrin-coated vesicles responsible for the(More)
In MDCK cells, transport of membrane proteins to the basolateral plasma membrane has been shown to require a distinct cytoplasmic domain determinant. Although the determinant is often related to signals used for localization in clathrin-coated pits, inactivation of the coated pit domain in the human LDL receptor did not affect basolateral targeting. By(More)
The AP-1B clathrin adaptor complex is responsible for the polarized transport of many basolateral membrane proteins in epithelial cells. Localization of AP-1B to recycling endosomes (REs) along with other components (exocyst subunits and Rab8) involved in AP-1B-dependent transport suggested that RE might be an intermediate between the Golgi and the plasma(More)
The asymmetric distribution of proteins to distinct domains in the plasma membrane is crucial to the function of many polarized cells. In epithelia, distinct apical and basolateral surfaces are maintained by tight junctions that prevent diffusion of proteins and lipids between the two domains. Polarized neurons maintain axonal and somatodendritic plasma(More)
rab4 is a ras-like GTP-binding protein that associates with early endosomes in a cell cycle-dependent fashion. To determine its role during endocytosis, we generated stable cell lines that overexpressed mutant or wild-type rab4. By measuring endocytosis, transport to lysosomes, and recycling, we found that overexpression of wild-type rab4 had differential(More)
Receptors for the Fc region of IgG (FcyR)' are expressed in a number of hematopoietic cell types and play important roles in several immunological processes such as phagocytosis of opsonized particulate antigens (1), clearance of immune complexes (2, 3), antibody-dependent cellular cytotoxicity (4, 5), signalling the production of inflammatory mediators(More)
During receptor mediated endocytosis, at least a fraction of recycling cargo typically accumulates in a pericentriolar cluster of tubules and vesicles. However, it is not clear if these endosomal structures are biochemically distinct from the early endosomes from which they are derived. To better characterize this pericentriolar endosome population, we(More)
Localization of the 215 kd mannose 6-phosphate receptor (MPR) was studied in normal rat kidney cells. Low levels of receptor were detected in the trans Golgi network, Golgi stack, plasma membrane, and peripheral endosomes. The bulk of the receptor was localized to an acidic, reticular-vesicular structure adjacent to the Golgi complex. The structure also(More)
Although polarized epithelial cells are well known to maintain distinct apical and basolateral plasma membrane domains, the mechanisms responsible for targeting membrane proteins to the apical or basolateral surfaces have remained elusive. We have identified a novel form of the AP-1 clathrin adaptor complex that contains as one of its subunits mu1B, an(More)