p120-catenin (p120) binds to the cytoplasmic tails of classical cadherins and inhibits cadherin endocytosis. Although p120 regulation of cadherin internalization is thought to be important for adhesive junction dynamics, the mechanism by which p120 modulates cadherin endocytosis is unknown. In this paper, we identify a dual-function motif in classical cadherins consisting of three highly conser...

Two models have been proposed for endophilin function in synaptic vesicle (SV) endocytosis. The scaffolding model proposes that endophilin's SH3 domain recruits essential endocytic proteins, whereas the membrane-bending model proposes that the BAR domain induces positively curved membranes. We show that mutations disrupting the scaffolding function do not impair endocytosis, whereas those disru...

Dendritic cells (DCs) are professional antigen-presenting cells (APCs) that use 2 major pathways for antigen uptake: constitutive macropinocytosis and mannose receptor-mediated endocytosis. Efficient endocytosis is critical for DCs to fulfill their sentinel function in immunity. We investigated the influence of the immunosuppressive macrolide rapamycin on macropinocytosis of fluorescein isothio...

Synaptic transmission between baroreceptor afferents and the nucleus tractus solitarius (NTS) is known to exhibit frequency-dependent depression. Reductions in neurotransmitter release and alterations in mechanisms regulating synaptic transmission are hypothesized to be involved in the activity-dependent depression observed in baroreceptor afferent neurons. The present study utilized cultured a...

The flotillins/reggie proteins are associated with noncaveolar membrane microdomains and have been implicated in the regulation of a clathrin- and caveolin-independent endocytosis pathway. Endocytosis is required for the amyloidogenic processing of the amyloid precursor protein (APP) and thus to initiate the release of the neurotoxic beta-amyloid peptide (Abeta), the major component of extracel...

Endocytosis is essential in maintaining exocytosis at secretory cells. Rapid endocytosis with a time course less than a few seconds is widely observed at nerve terminals and non-neuronal secretory cells. It is generally assumed that rapid endocytosis recycles vesicles within the readily releasable pool (RRP) via a kiss-and-run mechanism that involves rapid opening and closure of a fusion pore a...

Proteinuria predicts the decline of renal function in chronic kidney disease. Reducing albuminuria has been shown to be associated with a reduction in this rate of decline. Proximal tubular epithelial cells (PTECs), when exposed to albumin produce matrix proteins, proinflammatory and profibrotic cytokines like TGF-beta(1). Some of these effects are dependent on endocytosis of albumin by PTECs. ...

Although the calcium/calmodulin-activated phosphatase calcineurin may dephosphorylate many endocytic proteins, it is not considered a key molecule in mediating the major forms of endocytosis at synapses-slow, clathrin-dependent and the rapid, clathrin-independent endocytosis. Here we studied the role of calcineurin in endocytosis by reducing calcium influx, inhibiting calmodulin with pharmacolo...

Opioid drugs, such as morphine, are among the most effective analgesics available. However, their utility for the treatment of chronic pain is limited by side effects including tolerance and dependence. Morphine acts primarily through the mu-opioid receptor (MOP-R) , which is also a target of endogenous opioids. However, unlike endogenous ligands, morphine fails to promote substantial receptor ...

Agouti-related protein (Agrp), one of the two naturally occurring inverse agonists known to inhibit G protein-coupled receptor activity, regulates energy expenditure by decreasing basal and blocking agonist-promoted melanocortin receptor (MCR) signaling. Here we report that, in addition to its inverse agonistic activities, Agrp exhibits agonistic properties on the endocytosis pathway of melanoc...