TRAIL-death receptor endocytosis and apoptosis are selectively regulated by dynamin-1 activation

Abstract

Clathrin-mediated endocytosis (CME) constitutes the major pathway for uptake of signaling receptors into eukaryotic cells. As such, CME regulates signaling from cell-surface receptors, but whether and how specific signaling receptors reciprocally regulate the CME machinery remains an open question. Although best studied for its role in membrane fission, the GTPase dynamin also regulates early stages of CME. We recently reported that dynamin-1 (Dyn1), previously assumed to be neuron-specific, can be selectively activated in cancer cells to alter endocytic trafficking. Here we report that dynamin isoforms differentially regulate the endocytosis and apoptotic signaling downstream of TNF-related apoptosisinducing ligand-death receptor (TRAIL-DR) complexes in several cancer cells. Whereas the CME of constitutively internalized transferrin receptors is mainly dependent on the ubiquitously expressed Dyn2, TRAIL-induced DR endocytosis is selectively regulated by activation of Dyn1. We show that TRAIL stimulation activates ryanodine receptor-mediated calcium release from endoplasmic reticulum stores, leading to calcineurin-mediated dephosphorylation and activation of Dyn1, TRAIL-DR endocytosis, and increased resistance to TRAIL-induced apoptosis. TRAIL-DR-mediated ryanodine receptor activation and endocytosis is dependent on early caspase-8 activation. These findings delineate specific mechanisms for the reciprocal crosstalk between signaling and the regulation of CME, leading to autoregulation of endocytosis and signaling downstream of surface receptors.clathrin-mediated endocytosis | calcineurin | ryanodine receptor | programmed cell death | caspases R eceptor-mediated endocytosis plays a critical role in regulating signaling, by either promoting rapid endocytosis of ligandreceptor complexes and attenuating cell-surface signaling, or by promoting the formation of endosomes that can serve as signaling platforms for these complexes (1, 2). Clathrin-mediated endocytosis (CME) is one of the most important and well-characterized endocytic pathways in eukaryotes (3, 4). The CME core components-clathrin, dynamin, and adaptor protein 2 (AP2)-interact with several endocytic accessory proteins to initiate, stabilize, and promote the maturation of clathrin-coated pits (CCPs). Following maturation, CCP scission is catalyzed by the large GTPase dynamin, leading to the formation of cargo-containing vesicles (5, 6). Once thought to be a constitutive process, it is now recognized that CME can be highly regulated (7), but many questions remain as to the molecular mechanisms underlying the regulation of CME. Moreover, recent data have suggested that signaling G protein-coupled receptors (GPCRs) can directly regulate CCP dynamics through selective recruitment of dynamin and endocytic accessory proteins (8, 9). The extent of possible crosstalk between signaling receptors and CME has not been explored.Dynamins are master regulators of CME. In addition to their role in promoting the fission of invaginated CCPs, dynamins control earlier rate...

Selective regulation of clathrin-mediated epidermal growth factor receptor signaling and endocytosis by phospholipase C and calcium

“…PLCγ1 has also been proposed to regulate endocytosis by acting as a guanyl exchange factor for dynamin1 in neuronal cells (Choi et al. , 2004), and dynamin1 selectively regulates the clathrin-mediated endocytosis of tumor necrosis factor–related apoptosis-inducing ligand (TRAIL)-death receptor (DR) (Reis et al. , 2017).…”

“…Moreover, calcineurin and dynamin1 were dispensable for the internalization of EGFR (Figure 4A and Supplemental Figure 3, A and B), suggesting that Ca 2+ -dependent control of clathrin-mediated endocytosis in RPE cells does not rely on acute dephosphorylation of endocytic proteins such as dynamin1 by calcineurin, a phenomenon that regulates the clathrin-mediated endocytosis of TRAIL/DR (Reis et al. , 2017).…”

The big and intricate dreams of little organelles: Embracing complexity in the study of membrane traffic

“…68,69 Further comparative analysis of the CME of distinct receptors has found differences in requirements for lipids, 70 auxiliary proteins, 68,[71][72][73][74] and regulation by intracellular calcium. 75 Collectively these studies have revealed that understanding the systematic regulation of CME may be best accomplished by complementing assays that monitor the traffic of individual cargo receptors with systematic study of CCPs.…”

ERK1/2-dependent activation of FCHSD2 drives cancer cell-selective regulation of clathrin-mediated endocytosis

“…These cell type differences might reflect the immortalization process (45) or the strong dependence on supplemental EGF for growth and maintenance of the HBEC cell line (see Methods). Alternatively, they may reflect cell-type and/or cargo-dependent differences in endocytic machinery as previously observed for death receptor-dependent endocytosis (46).…”

“…Hyperactivity of EGFR signaling at the cell surface is a common feature among different types of cancers and widely considered advantageous for tumor progression (46). Why then, would ERK1/2 activation downstream of EGFR activate a mechanism that enhances CCP initiation and EGFR endocytosis and suppresses EGFR proliferative and migratory signaling?…”