• We will discuss these emerging new findings and their implications for the nature of lipid rafts themselves, as well as for the potential roles of non-clathrin endocytic pathways in remodeling of the plasma membrane and in regulating the membrane composition of specific intracellular organelles. (nih.gov)
  • C) Total number of clathrin/AP2-coated structures (CCS per cell) on the plasma membrane of a cell as determined by counting the number of fluorescent AP2 spots detected in each whole z stack obtained by 3D live-cell imaging. (nih.gov)
  • Suggesting that clathrin-coated membranes serve as one source of signaling endosomes, in earlier studies we showed that nerve growth factor (NGF) treatment increased clathrin at the plasma membrane and resulted in colocalization of clathrin with TrkA, the receptor tyrosine kinase for NGF. (jneurosci.org)
  • Flat clathrin lattices: stable features of the plasma membrane. (nih.gov)
  • The molecular exchange of clathrin triskelia between the cytosolic pool and CCSs at the plasma membrane remains a contentious topic. (nih.gov)
  • Here, we show that the R-SNAREs VAMP8, VAMP3, and VAMP2, which cycle between the plasma membrane and endosomes, bind directly to the ubiquitously expressed, PtdIns4,5P 2 -binding, endocytic clathrin adaptor CALM/PICALM. (pubmedcentralcanada.ca)
  • This causes the protein clathrin to assemble into a lattice at the cytosolic side of the plasma membrane and deform the membrane into a pit. (elifesciences.org)
  • We show that heregulin-stimulation induces trafficking of phosphorylated ErbB3 from the plasma membrane to the nucleus via a clathrin-independent mechanism. (pubmedcentralcanada.ca)
  • The demonstration that nerve growth factor (NGF) increased the number of coated pits at the plasma membrane of sympathetic neurons ( 9 ) and that NGF signaled through tyrosine kinase receptor A to increase clathrin at the plasma membrane and in this way enhanced clathrin-mediated membrane trafficking ( 2 ) could argue that NGF would induce formation of new clathrin-coated pits at the plasma membrane. (asm.org)
  • It was also demonstrated that ligand-binding to the EGFR, the T cell receptor, and the B cell receptor through Src-induced phosphorylation of clathrin influenced the distribution of clathrin at the plasma membrane ( 10 , 37 , 41 ). (asm.org)
  • Induced formation of coated pits at the plasma membrane was recently demonstrated in the case of viruses, where influenza viruses taking the clathrin pathway were demonstrated to enter cells via de novo formation of clathrin-coated pits at sites of virus binding ( 30 ). (asm.org)
  • The majority of clathrin on the plasma membrane of these cells (>60%) was found in large clathrin patches that displayed virtually no lateral mobility and persisted for many minutes, and a smaller amount was found in small spots that appeared and disappeared rapidly. (umassmed.edu)
  • Ap-2, the plasma membrane adaptor complex which recruits clathrin and are Eps15 that required in the CME [ 18 , 19 ]. (hindawi.com)
  • Various non-clathrin endocytic mechanisms have been identified, including uptake through caveolae, macropinosomes and via a separate constitutive pathway. (nih.gov)
  • We show that XCL is endocytosed by the clathrin-dependent pathway, and is delivered to late endosome/lysosome compartments. (biomedsearch.com)
  • The results of this study for the first time demonstrate that not only the clathrin-dependent pathway but also macropinocytosis are involved in fish DNA enveloped virus entry, thus providing a convenient tactic for exploring the life cycle of DNA viruses. (sigmaaldrich.com)
  • These findings support the existence of a pathway for SV reformation that bypasses the requirement for clathrin and dynamin 1/3 and that operates during intense synaptic activity. (elifesciences.org)
  • These findings point to the occurrence of a pathway of synaptic vesicle recycling that bypasses the need for dynamin 1 and 3 as well as for clathrin. (elifesciences.org)
  • However, the EGFR can also be internalized through (a) clathrin-independent pathway(s), and it remains unclear why distinct mechanisms of internalization have evolved. (nih.gov)
  • Our results indicate a mechanism, whereby retromer can regulate endosomal clathrin dynamics through RME‐8 and Hsc70, promoting the sorting of recycling cargo into the retrograde pathway. (embopress.org)
  • Earlier findings in this laboratory suggested that clathrin-coated membranes may be used to move NTs and their receptors into signaling endosomes. (jneurosci.org)
  • Remarkably, overexpression of endofin led to a massive and specific recruitment of clathrin [but not dynamin, or the adaptor protein (AP) complexes, AP1, AP2 or APonto endofin-positive endosomes. (biologists.org)
  • The subsequent conversion of bulk endosomes into SVs was not accompanied by the accumulation of clathrin coated buds on their surface and this process proceeded even after further clathrin knock-down, suggesting its independence of clathrin. (elifesciences.org)
  • Considerably less is known about the formation of clathrin coated carriers at the TGN and endosomes, where the adaptor protein complex AP-1 plays a major role. (unibas.ch)
  • Clathrin-dependent entry mostly follows the route from early endosomes (EE) to late endosomes (LE), and further to lysosomes for degradation or conformation changes. (hindawi.com)
  • Clathrin light-chain binds to a flexible coiled-coil domain in HIP1 and induces a compact state that is refractory to actin binding [ PMID: 20179344 ]. (ebi.ac.uk)
  • The deep invagination of clathrin-coated pits that leads to fission is assisted by actin, a protein that assembles into filaments that are suggested to generate the forces needed for this process. (elifesciences.org)
  • Overall, these results suggest that a main role of epsin is to help actin interact with the clathrin-coated pits and generate the force required for a pit to develop into a vesicle. (elifesciences.org)
  • The role of actin downstream of clathrin seems to be critical for this still poorly characterized process. (pasteur.fr)
  • E) Upper panel: plot of the individual lifetimes of clathrin/AP2 pits from HeLa and BSC1 cells calculated from 4D time series obtained from the bottom and top surfaces during metaphase and cytokinesis, or from 2D and 4D time series from the bottom and top surfaces of interphase cells. (nih.gov)
  • Clathrin-coated pits contain an integral membrane protein that binds the AP-2 subunit with high affinity. (semanticscholar.org)
  • It occurs on the membrane via clathrin-coated pits (CCPs). (umich.edu)
  • EGFR and PTEN localize to short-lived clathrin-coated pits (CCPs), and PTEN regulates CCP dynamics and signaling, suggesting compartmentalized signaling is crucial for proper signaling transduction. (biologists.org)
  • Our results indicate that a key evolutionary conserved function of epsin, in addition to other roles that include, as we show here, a low affinity interaction with SNAREs, is to help generate the force that leads to invagination and then fission of clathrin-coated pits. (elifesciences.org)
  • By immunoelectron microscopy, we found that in AP2-depleted cells, the number of clathrin-coated pits was strongly reduced. (asm.org)
  • Induction of clathrin-coated pits required EGFR kinase activity. (asm.org)
  • Our data demonstrate that EGFR-induced signaling and Grb2 are essential for formation of clathrin-coated pits accommodating the EGFR, while activation of MAPK and PI3K is not required. (asm.org)
  • Additionally, ligand-binding results in localization of the EGFR to clathrin-coated pits, from where the EGFR is endocytosed at physiological concentrations of EGF ( 21 , 42 ). (asm.org)
  • Consistently, our recent data demonstrated that even though EGFR and TfR to some extent colocalized in clathrin-coated pits, more EGFR was found in TfR-negative coated pits than in TfR-positive coated pits ( 36 ). (asm.org)
  • This highlights the idea of potential EGFR-specific adaptor molecules in clathrin-coated pits. (asm.org)
  • We have recently demonstrated that overexpression of Grb2 with inactivating point mutations in both SH3 domains (d.n.Grb2), as well as overexpression of human Sprouty 2, inhibiting the enzymatic activity of Cbl, inhibited the EGF-induced transport of the EGFR to clathrin-coated pits. (asm.org)
  • Since clathrin-coated pits are planar structures, whereas CVs are spherical, there must be a structural rearrangement of clathrin as invagination occurs. (rupress.org)
  • This could occur through simple addition of clathrin triskelions to the edges of growing clathrin-coated pits with very little exchange occurring between clathrin in the pits and free clathrin in the cytosol, or it could occur through large scale exchange of free and bound clathrin. (rupress.org)
  • rather, it is caused by a rapid ATP-dependent exchange of clathrin in the pits with free clathrin in the cytosol. (rupress.org)
  • Then as the cargoes being enclosed in clathrin-coated pits, they slow down the active rotation and experience a quiet period before they restore active rotational diffusion after fission and eventually being transported away from the original entry spots. (nature.com)
  • Researchers of the group of cellular and molecular neurobiology of the Bellvitge Biomedical Research Institute (IDIBELL) and the University of Barcelona, led by researcher Artur Llobet, have shown that synaptic levels of the protein clathrin are a determinant factor for synaptic plasticity of neurons. (eurekalert.org)
  • Of importance, the interaction between clathrin light and heavy chain is very stable, such that the molecular dynamics of LCb-RFP faithfully represents the behavior of clathrin triskelia subunits (Hoffmann et al. (nih.gov)
  • Cleveland analysis of the in vivo and in vitro clathrin heavy chain phosphopeptides, generated by protease V8 digestion, show labeled proteolytic fragments of similar molecular weight, suggesting that pp60v-src could be directly responsible for the in vivo phosphorylation of clathrin. (rupress.org)
  • The dynamics of clathrin-coated pit formation and the uptake of transferrin are maintained in naturally dividing cells but are nearly absent in mitotic cells arrested chemically by treatment with nocodazole, S-Trityl-L-cysteine, or RO-3306. (nih.gov)
  • In addition, the structures isolated from auxilin-depleted cells are on average smaller than CCVs from control cells and are largely devoid of membrane, indicating that they are not CCVs but membraneless clathrin cages. (biomedsearch.com)
  • Together, these findings indicate that the two auxilins have overlapping functions and that they not only facilitate the uncoating of CCVs but also prevent the formation of nonproductive clathrin cages in the cytosol. (biomedsearch.com)
  • 2011). Furthermore, completion of CME requires the active disassembly of clathrin from CCVs by Hsc70 and auxillin/GAK (Schlossman et al. (nih.gov)
  • These biochemical and cell biological data point to a role for epsinR in AP1/clathrin budding events in the cell, just as epsin1 is involved in the budding of AP2 CCVs. (ox.ac.uk)
  • In the present study, we investigated this question by studying clathrin exchange both in vitro and in vivo. (rupress.org)
  • We found that in vitro clathrin in CVs and clathrin baskets do not exchange with free clathrin even in the presence of Hsc70 and ATP where partial uncoating occurs. (rupress.org)
  • Clathrin heavy chain is a substrate for pp60v-src in vitro. (rupress.org)
  • We have developed quantitative and complementary in vivo and in vitro assays for endocytic clathrin coated vesicle (CCV) formation and will use these to probe the fundamental mechanisms underlying CME. (grantome.com)
  • Using these assays, we will pursue three major aims: 1) To quantitatively define factors that regulate clathrin coated pit initiation and maturation in vivo, including cargo, PI4,52, v-SNAREs and AP2 interactions;2) To define the role of SH3 domain-containing dynamin-1 effectors as regulators of dynamin function in CCV formation in vivo and in vitro;and 3) To reconstitute CCV formation from SUPER templates using purified protein components. (grantome.com)
  • The Phosphatidylinositol Binding Clathrin Assembly Protein (PICALM) ELISA kit is intended to be used for research purposes only and it is not applicable to in vitro diagnostic procedures. (phosphatidylinositol.com)
  • We interfered with clathrin heavy chain (CHC) function through mutants and dominant-negative approaches in Arabidopsis thaliana and established tools to manipulate clathrin function in a cell type-specific manner. (ugent.be)
  • Clathrin assembly lymphoid myeloid leukemia protein (CALM) is a homologue of AP180 whose ANTH domain shares 81% sequence homology. (cam.ac.uk)
  • The correlation between the ability of endofin to interact with the C-terminal domain of TOM1 and clathrin recruitment suggests that endofin may recruit clathrin via TOM1. (biologists.org)
  • Indeed, a chimeric protein consisting of TOM1 fused to two FYVE domains derived from endofin has the ability to recruit clathrin onto endosomal structures. (biologists.org)
  • EpsinR is a clathrin-coated vesicle (CCV) enriched 70-kD protein that binds to phosphatidylinositol-4-phosphate, clathrin, and the gamma appendage domain of the adaptor protein complex 1 (AP1). (ox.ac.uk)
  • Loss of SNX-1, RME-8, or the clathrin chaperone Hsc70/HSP-1 leads to over-accumulation of endosomal clathrin, reduced clathrin dynamics, and missorting of MIG-14 to the lysosome. (antibodies-online.com)
  • Finally, we observed that clathrin and AP-1 knockdown altered the endosomal distribution of HCV core, reducing and increasing its colocalization with early endosome and lysosome markers, respectively. (asm.org)
  • To reveal the biological consequence of endofin-mediated endosomal recruitment of TOM1, we have identified the clathrin heavy chain as a major interacting protein for TOM1. (biologists.org)
  • Endosome‐associated clathrin also affects the recycling of retrograde cargo and has been shown to function in the formation of endosomal subdomains. (embopress.org)
  • In this study, the genes ZmCHC1 and ZmCHC2 encoding clathrin heavy chain in maize were cloned and characterized for the first time in monocots. (mdpi.com)
  • To investigate the role of clathrin-mediated trafficking during the Leishmania lifecycle, open reading frames encoding clathrin heavy chain and the β-adaptins, major components of the adaptor complexes, have been analysed both in silico and experimentally. (dur.ac.uk)
  • To explore this possibility further, we examined the distribution of clathrin in NGF- and BDNF-treated cells. (jneurosci.org)
  • Divergent modes for cargo-mediated control of clathrin-coated pit dynamics. (berkeley.edu)
  • The in vivo assays utilize total internal reflection fluorescence microscopy coupled with novel tracking software and statistical analyses that allow us to comprehensively and quantitatively analyze clathrin coated pit (CCP) dynamics and the kinetics of CCV formation in living cells. (grantome.com)
  • B) Surface density of clathrin/AP2-coated structures (CCS/100 µm 2 ) calculated from the number of AP2 spots at the top and bottom surfaces of HeLa and BSC1 cells imaged during interphase, metaphase, and cytokinesis prior to abscission. (nih.gov)
  • The result was an increase in large clathrin-coated structures (CCS) on the surface of the cells. (fredhutch.org)
  • The clathrin structures that formed in these manipulated cells recruited integrin β1 normally. (fredhutch.org)
  • Although most of the clathrin structures were found to contain both Dab2 and AP2, the authors showed that integrin β1 and TfnR do not co-localize on the cell surface. (fredhutch.org)
  • The general objective of our lab is to understand the functions of clathrin-coated structures (CCSs) during the different steps of cancer development. (ipbs.fr)
  • The canonical hairpin repeat of the clathrin superhelix resembles a tetratrico peptide repeat (TPR), but is shorter and lacks the characteristic spacing of the hydrophobic residues in TPRs. (embl.de)
  • The main clathrin heavy chain, located on chromosome 17 in humans, is found in all cells. (wikipedia.org)
  • Clathrin-coated vesicle formation was inhibited by incubating cells in hypertonic medium or by depletion of cytosolic potassium. (mcmaster.ca)
  • Inhibition of several kinases selectively affected CME in cancer cells, including inhibition of ERK1/2, which selectively inhibited CME by decreasing the rate of clathrin-coated pit (CCP) initiation. (pnas.org)
  • However, small interfering RNA (siRNA) knockdown of the ubiquitous auxilin 2 in HeLa cells only moderately impairs clathrin-dependent trafficking. (biomedsearch.com)
  • CCV fractions isolated from auxilin-depleted cells have an approximately 1.5-fold increase in clathrin content and more than fivefold increase in the amount of AP-2 adaptor complex and other endocytic machinery, with no concomitant increase in cargo. (biomedsearch.com)
  • Our data support a model in which nascent HCV particles associate with apoE in the ER and exit cells following a clathrin-dependent transendosomal secretory route. (asm.org)
  • Here we demonstrate for the first time that clathrin also participates in HCV exit from infected cells. (asm.org)
  • Strikingly, however, we also noted that most clathrin puncta at the surface of NGF-treated cells did not colocalize with TrkA, raising the possibility that NGF induces a general increase in clathrin-coated membrane formation. (jneurosci.org)
  • We have shown that the heavy chain of clathrin is phosphorylated in chicken embryo fibroblast cells transformed by Rous sarcoma virus, but not in normal cells. (rupress.org)
  • In cultured cells, most of the clathrin is localized to large patches that display little lateral mobility. (umassmed.edu)
  • Here we have analyzed clathrin organization in primary adipose cells isolated from mice, which are nonadherent and fully differentiated. (umassmed.edu)
  • Clathrin functions as a trimer, and these trimers, or triskelions, are comprised of three legs joined by a central vertex. (embl.de)
  • Our results show that clathrin function at the PM is required to induce plant defense responses, likely through CME of cell surface-located signaling components. (ist.ac.at)