Dynamin-dependent Transferrin Receptor Recycling by Endosome-derived Clathrin-coated Vesicles

Abstract

Previously we described clathrin-coated buds on tubular early endosomes that are distinct from those at the plasma membrane and the trans-Golgi network. Here we show that these clathrincoated buds, like plasma membrane clathrin-coated pits, contain endogenous dynamin-2. To study the itinerary that is served by endosome-derived clathrin-coated vesicles, we used cells that overexpressed a temperature-sensitive mutant of dynamin-1 (dynamin-1 G273D ) or, as a control, dynamin-1 wild type. In dynamin-1 G273D -expressing cells, 29 -36% of endocytosed transferrin failed to recycle at the nonpermissive temperature and remained associated with tubular recycling endosomes. Sorting of endocytosed transferrin from fluid-phase endocytosed markers in early endosome antigen 1-labeled sorting endosomes was not inhibited. Dynamin-1 G273D associated with accumulated clathrin-coated buds on extended tubular recycling endosomes. Brefeldin A interfered with the assembly of clathrin coats on endosomes and reduced the extent of transferrin recycling in control cells but did not further affect recycling by dynamin-1 G273D -expressing cells. Together, these data indicate that the pathway from recycling endosomes to the plasma membrane is mediated, at least in part, by endosome-derived clathrin-coated vesicles in a dynamindependent manner.

Constitutive Endocytic Cycle of the CB1 Cannabinoid Receptor

“…5C). In addition, other compounds that have been shown to inhibit recycling of the TfR receptor (28,29) and of the AT 1A angiotensin II receptor (13), the phosphoinositide 3-kinase inhibitors wortmannin and LY294002, and brefeldin A also inhibit CB1R externalization induced by AM281 (data not shown). These compounds have a broad range of cellular effects; they unravel the constitutive endocytosis of CB1R and indicate that AM281 may act through constitutive recycling but do not allow unambiguous identification of the intracellular pathways involved.…”

Clathrin Terminal Domain-Ligand Interactions Regulate Sorting of Mannose 6-Phosphate Receptors Mediated by AP-1 and GGA Adaptors

“…Recycling of Transferrin Is Independent of Clathrin TD Function-Clathrin coats in addition to the plasma membrane and the TGN have also been observed on endosomes (23,24,47), where they are involved in polarized sorting to the basolateral surface in epithelial cells, among possible other functions (48). A highly dynamic form of endosomal clathrin (termed G-clathrin) has been postulated to regulate rapid recycling (27).…”

Vesicular transport of Fe and interaction with other metal ions in polarized Caco2 Cell monolayers

“…Nocodazole depolymerizes microtubules and promotes dispersal and tubulation of the Golgi apparatus (Turner and Tartakoff, 1989). Brefeldin A disrupts the Golgi apparatus (Lippincott-Schwartz et al, 1990) but also has been reported to interfere with normal sorting and recycling of the holotransferrin bound to its receptor in endocytic vesicles (Xia and Shen, 2001;van Dam and Stoorvogel, 2002). Tyrphostin A8 (AG10) inhibits a GTPase (Rab17) necessary for the fusion of vesicles and endosomes in the apical region of polarized epithelial cells (Lütcke et al, 1993;Hunziker and Peters, 1998;Zacchi et al, 1998;Knight et al, 1995;Hughson and Hopkins, 1990).…”