Identification by anti-idiotype antibodies of an intracellular membrane protein that recognizes a mammalian endoplasmic reticulum retention signal

Vaux, David J.; Tooze, John; Fuller, Stephen D.

doi:10.1038/345495a0

Cited by 250 publications

(179 citation statements)

References 34 publications

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“…Two-dimensional NMR analysis of synthetic peptides containing known tyrosine-based clathrincoated pit-interacting motifs suggests that tyrosine residues often lie within a conserved structural feature, either a tight turn (Vaux et al, 1992) or a surface loop (Ktistakis et al, 1990;Trowbridge et al, 1993). Similarly, tyrosine-and nontyrosine-based basolateral signals are frequently characterized by ␤ turns or loop-like secondary structures such that mutation prevents appropriate interaction with the trafficking machinery (Aroeti et al, 1993;Reich et al, 1996;Aroeti et al, 1998).…”

Section: Discussionmentioning

confidence: 99%

A Unique Element in the Cytoplasmic Tail of the Type II Transforming Growth Factor-β Receptor Controls Basolateral Delivery

Murphy

Shapira

Henis

et al. 2007

MBoC

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Transforming growth factor (TGF)-␤ receptors stimulate diverse signaling processes that control a wide range of biological responses. In polarized epithelia, the TGF␤ type II receptor (T2R) is localized at the basolateral membranes. Sequential cytoplasmic truncations resulted in receptor missorting to apical surfaces, and they indicated an essential targeting element(s) near the receptor's C terminus. Point mutations in the full-length receptor confirmed this prediction, and a unique basolateral-targeting region was elucidated between residues 529 and 538 (LTAxxVAxxR) that was distinct, but colocalized within a clinically significant signaling domain essential for TGF␤-dependent activation of the Smad2/3 cascade. Transfer of a terminal 84 amino-acid fragment, containing the LTAxxVAxxR element, to the apically sorted influenza hemagglutinin (HA) protein was dominant and directed basolateral HA expression. Although delivery to the basolateral surfaces was direct and independent of any detectable transient apical localization, fluorescence recovery after photobleaching demonstrated similar mobility for the wild-type receptor and a missorted mutant lacking the targeting motif. This latter finding excludes the possibility that the domain acts as a cell membrane retention signal, and it supports the hypothesis that T2R sorting occurs from an intracellular compartment. INTRODUCTIONEpithelial cells form highly polarized monolayers that generate two morphologically and functionally distinct domains, an apical luminal facing domain and a basolateral domain that separates the epithelia from the underlying mesenchyme. Because the maintenance of cell polarity is dependent upon the asymmetrical distribution of proteins and lipids to precise locales on the cell surface (Rodriguez-Boulan et al., 2005), a number of cis-acting targeting signals have been described mediating protein sorting. For example, basolateral delivery is often regulated by minimal amino acid motifs in the cytoplasmic region of a wide range of membrane proteins, often being localized to juxtamembrane locales (Aroeti et al., 1998;Ikonen and Simons, 1998; RodriguezBoulan et al., 2005). Although extensive heterogeneity exists, certain features commonly arise in the amino acid sequences. Specifically, the targeting of many basolateral proteins, including the low-density lipoprotein receptor and vesicular stomatitis virus glycoprotein, have been demonstrated to be regulated by tyrosine-based motifs (Matter et al., 1992;Thomas et al., 1993) and a consensus sequence, YXX (where X is any amino acid and represents a large hydrophobic residue), has been proposed to be needed for correct trafficking (Hunziker and Mellman, 1991;Matter et al., 1992;Honing and Hunziker, 1995;Aroeti et al., 1998). Moreover, bipartite sorting signals and dihydrophobic residues such as dileucine (LL) motifs have also figured highly as effectors of basolateral trafficking (Hunziker and Fumey, 1994;Miranda et al., 2001). However, for many other reported basolaterally located proteins, the exac...

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Section: Discussionmentioning

confidence: 99%

A Unique Element in the Cytoplasmic Tail of the Type II Transforming Growth Factor-β Receptor Controls Basolateral Delivery

Murphy

Shapira

Henis

et al. 2007

MBoC

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“…Ultrathin sections were cut onto nickel grids and contrast-enhanced with uranyl acetate and lead citrate. Immunolabelling for protein disulphide isomerase used methods described previously [28] and 15 nm protein A gold (Biocell, Cardiff, UK). Sections were examined in the Joel 1010 microscope with an accelerating voltage of 80 kV.…”

Section: Preparation Of Fatty Acidsmentioning

confidence: 99%

Adverse physicochemical properties of tripalmitin in beta cells lead to morphological changes and lipotoxicity in vitro

et al. 2005

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Aims/hypothesis: Long-term exposure of beta cells to lipids, particularly saturated fatty acids in vitro, results in cellular dysfunction and apoptosis (lipotoxicity); this could contribute to obesity-related diabetes. Our aims were to relate cell death to intracellular triglyceride concentration, composition and localisation following incubation of INS1 cells in saturated and unsaturated NEFA in high and low glucose concentrations. Materials and methods: In sulin-producing INS1 cells were cultured (24 h; 3 and 20 mmol/l glucose) with palmitic, oleic or linoleic acids and the resulting intracellular lipids were analysed by gas chromatography and microscopy. Cell death was determined by quantitative microscopy and 3-(4,5-dimethlthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and glucose-stimulated insulin secretion by ELISA. Results: All NEFA (0.5 mmol/l, 0.5% albumin) inhibited glucose-stimulated (20 mmol/l) insulin secretion. Cytotoxicity was evident only with palmitic acid (p<0.05), in which case intracellular triglyceride consisted largely of tripalmitin in angular-shaped dilated endoplasmic reticulum. Cytotoxicity and morphological disruption were reduced by addition of unsaturated NEFA. Triglyceridecontent (control cells; 14.5 ng/μg protein) increased up to 10-fold following incubation in NEFA (oleic acid 153.2 ng/μg protein; p<0.05) and triglyceride and phospholipid fractions were both enriched with the specific fatty acid added to the medium (p<0.05). Conclusions/ interpretation: In INS1 cells, palmitic acid is converted in the endoplasmic reticulum to solid tripalmitin (melting point >65C), which could induce endoplasmic reticulum stress proteins and signal apoptosis; lipid-induced apoptosis would therefore be a consequence of the physicochemical properties of these triglycerides. Since cellular triglycerides composed of single species of fatty acid are not likely to occur in vivo, destruction of beta cells by saturated fatty acids could be predominantly an in vitro scenario.

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“…The mouse monoclonal 1D3 antibody (1D3, gift from D. Vaux, Oxford, United Kingdom) was raised against the synthetic peptide corresponding to the 12 C terminus amino acids KDDDQKAVKDEL of human PDI that is a resident of the endoplasmic reticulum (Vaux et al, 1990). In the Drosophila homolog of PDI (P543991, CG6988), this sequence becomes EEEEEAPKKDEL exhibiting ϳ60% similarity (McKay et al, 1995).…”

Section: Drosophila Golgi Markers and Antibodiesmentioning

confidence: 99%

Biogenesis of Golgi Stacks in Imaginal Discs ofDrosophila melanogaster

Kondylis

Goulding

Dunne

et al. 2001

MBoC

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We provide a detailed description of Golgi stack biogenesis that takes place in vivo during one of the morphogenetic events in the lifespan of Drosophila melanogaster. In early third-instar larvae, small clusters consisting mostly of vesicles and tubules were present in epithelial imaginal disk cells. As larvae progressed through mid-and late-third instar, these larval clusters became larger but also increasingly formed cisternae, some of which were stacked. In white pupae, the typical Golgi stack was observed. We show that larval clusters are Golgi stack precursors by 1) localizing various Golgi-specific markers to the larval clusters by electron and immunofluorescence confocal microscopy, 2) driving this conversion in wild-type larvae incubated at 37°C for 2 h, and 3) showing that this conversion does not take place in an NSF1 mutant (comt 17). The biological significance of this conversion became clear when we found that the steroid hormone 20-hydroxyecdysone (ecdysone) is critically involved in this conversion. In its absence, Golgi stack biogenesis did not occur and the larval clusters remained unaltered. We showed that dGM130 and sec23p expression increases approximately three-and fivefold, respectively, when discs are exposed to ecdysone in vivo and in vitro. Taken together, these results suggest that we have developed an in vivo system to study the ecdysone-triggered Golgi stack biogenesis.

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Identification by anti-idiotype antibodies of an intracellular membrane protein that recognizes a mammalian endoplasmic reticulum retention signal

Cited by 250 publications

References 34 publications

A Unique Element in the Cytoplasmic Tail of the Type II Transforming Growth Factor-β Receptor Controls Basolateral Delivery

A Unique Element in the Cytoplasmic Tail of the Type II Transforming Growth Factor-β Receptor Controls Basolateral Delivery

Adverse physicochemical properties of tripalmitin in beta cells lead to morphological changes and lipotoxicity in vitro

Biogenesis of Golgi Stacks in Imaginal Discs ofDrosophila melanogaster

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