Deubiquitination by the Fat facets protein - a regulator of photoreceptor differentiation during Drosophila eye development - has been found to activate endocytosis, while ubiquitination inhibits endocytosis. Surprisingly, this is the opposite effect that ubiquitination has on endocytosis of many plasma membrane proteins.

Endocytosis plays a central role in many cell biological processes. Talks at the Minisymposium on “Membrane Traffic: Dynamics and Regulation,” Endocytosis Section, mainly focused on specific mechanistic aspects of endocytosis, addressing the questions of how cargoes are sorted into different endocytic vesicles and how vesicles pinch off from the plasma membrane or bud into multivesicular bodies...

Endocytosis of cell surface receptors is involved in down-regulation of receptor activity. Recent findings indicate that, paradoxically, endocytosis of a membrane-spanning ligand may up-regulate receptor activity: the zebrafish E3 ligase Mind bomb promotes the endocytosis of Delta and is required for efficient activation of Notch.

E xocytosis and endocytosis are the yin and yang of cellular transportation. By limiting where exocytosis can occur, endocytosis might help yeast cells polarize, Jose et al. reveal (1). The pole of a budding yeast cell is where the bud sprouts when the organism reproduces asexually. Like other eukaryotes, yeast cells polarize with help from the Rho GTPase Cdc42, which amasses at the site of the...

We discuss here the variety of approaches that have been taken to inhibit different forms of endocytosis. Typically, both non-specific and specific chemical inhibitors of endocytosis are tried in order to "classify" entry of a new plasma membrane protein into one of the various types of endocytosis. This classification can be confirmed through genetic approaches of protein depletion or overexpr...

Endocytosis is the process of internalization of extracellular material within an invagination of the plasmalemma. Ultimately, this invagination is thought to give rise to an independent cytoplasmic vesicle. This vesicle is given a more specific name (e.g. phagosome, pinosome, coated vesicle, primary food vacuole) depending on the cell type being studied and the mode of endocytosis involved. Hi...

BACKGROUND Free light chains (LCs) are among the many ligands that bind to cubilin/megalin for endocytosis via the clathrin-dependent endosomal/lysosomal pathway. Receptor associated protein (RAP), is a 39 kDA high-affinity, chaperone-like ligand for megalin that assists in the proper folding and functioning of megalin/cubilin. Although RAP is known to inhibit ligand binding to megalin/cubilin,...

The delta-opioid receptor (DOR) can undergo proteolytic down-regulation by endocytosis of receptors followed by sorting of internalized receptors to lysosomes. Although phosphorylation of the receptor is thought to play an important role in controlling receptor down-regulation, previous studies disagree on whether phosphorylation is actually required for the agonist-induced endocytosis of opioi...

Drug delivery to tumors is limited by several factors, including drug permeability of the target cell plasma membrane. Ultrasound in combination with microbubbles (USMB) is a promising strategy to overcome these limitations. USMB treatment elicits enhanced cellular uptake of materials such as drugs, in part as a result of sheer stress and formation of transient membrane pores. Pores formed upon...