196,211 research outputs found
The KDEL receptor: New functions for an old protein
No full textThe KDEL receptor is a seven-transmembrane-domain protein that was first described about 20 years ago. Its well-known function is to retrotransport chaperones from the Golgi complex to the endoplasmic reticulum. Recent studies, however, have suggested that the KDEL receptor has additional functions. Indeed, we have demonstrated that chaperone-bound KDEL receptor triggers the activation of Src family kinases on the Golgi complex. This activity is essential in the regulation of Golgi-to-plasma membrane transport. However, the identification of different KDEL receptor interactors that are inconsistent with these established functions opens the possibility of further receptor activities
SOI digital pixel sensor based on charge pumping
No full textIn this paper, a digital pixel sensor in SOl is presented. The active part is a partially depleted Sol phototransistor. The technique elaborated in [I] was designed and implemented. Moreover, we took advantage of some of the characteristics of the floating body SOl MOSFET to implement a first order delta sigma modulator in each pixel. Measured data show that the pixel has sensitivity of 3mW1m2 and a resolution of about 7bits. This pixel can be operated in two modes: Weak inversion (Idc =1.2μA) and moderate inversion (Idc =15μA).GR-KAEDLABElectrical Engineering, Ecole Polytechnique Federale de Lausanne, Lausanne, SwitzerlandExport Date: 19 January 2010Source: ScopusArt. No.: 5184778References: Harik, L., Sallese, J-M., Kayal, M., Transient charge pumping as an efficient technique to measure low light intensity with PD Sol MOSFET (2008) Solid-State Electronics, 52, pp. 597-605. , May; Hill, J.M., Lachman, J., A 900 MHz 2.25 MB cache with on chip CPU now in CU SOl ISSCC 2001, , Session 11 SRAM 11.5; Blagojevic, M., Kayal, M., Pastre, M., Harik, L., Declercq, M.J., Okhonin, S., Fazan, P.C., Capacitorless IT DRAM sensing scheme with automatic reference generation (2006) Solid-State Circuits, IEEE Journal, 41 (6), pp. 1463-1470. , June; Okhonin, S., Nagoga, M., Fazan, P., Principles of transient charge pumping on partially depleted SOI MOSFETs (2002) IEEE Electron Device Letters, 23 (5), pp. 279-281. , DOI 10.1109/55.998876, PII S0741310602045330; Candsy, J.C., Themes, G.C., Oversampling delta-sigma data converters (1992) IEEE Press; J-M., Sallese., A-S. Porret, A novel approach to charge-based nonquasi- static model of the MOS transistor valid in all modes of operation (2000) Solid-State Electronics, 44 (6), pp. 887-894; Sallese, J.-M., Bucher, M., Krummenacher, F., Fazan, P., Inversion charge linearization in MOSFET modeling and rigorous derivation of the EKV compact model (2003) Solid-State Electronics, 47, pp. 677-68
Delta-sigma loop based on charge pumping in SOI optical sensor
No full textIn this paper, the partially depleted SOI phototransistor has been used as a light intensity sensor. A pixel implementing the technique elaborated in [1] was designed and implemented on SOI technology. The circuit implements a first order delta-sigma modulator. Measured data show flux densities as low as 3mW/m2 and an SNR of 60 dB. © 2008 IEEE.GR-KAEDLABElectrical Engineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne, SwitzerlandExport Date: 19 January 2010Source: ScopusArt. No.: 4716704References: Harik, L., Sallese, J.-M., Kayal, M., Transient charge pumping as an efficient technique to measure low light intensity with PD SOI MOSFET (2008) Solid-State Electronics, 52, pp. 597-605; Hill, J.M., Lachman, J., A 900 MHz 2.25 MB cache with on chip CPU now in CU SOI (2001) ISSCC, , Session 11 SRAM 11.5; Okhonin, S., Nagoga, M., Fazan, P., Principles of transient charge pumping on partially depleted SOI MOSFETs (2002) IEEE Electron Device Letters, 23 (5), pp. 279-281. , DOI 10.1109/55.998876, PII S0741310602045330; Candsy, J.C., Themes, G.C., (1992) Oversampling Delta-Sigma Data Converters, , IEEE Press; Sallese, J.-M., Bucher, M., Krummenacher, F., Fazan, P., Inversion charge linearization in MOSFET modeling and rigorous derivation of the EKV compact model (2003) Solid-State Electronics, 47, pp. 677-68
The physiology of membrane transport and endomembrane-based signalling
No full textSome of the important open questions concerning the physiology of the secretory pathway relate to its homeostasis. Secretion involves a number of separate compartments for which their transport activities should be precisely cross-coordinated to avoid gross imbalances in the trafficking system. Moreover, the membrane fluxes across these compartments should be able to adapt to environmental 'requests' and to respond to extracellular signals. How is this regulation effected? Here, we consider evidence that endomembrane-based signalling cascades that are similar in organization to those used at the plasma membrane coordinate membrane traffic. If this is the case, this would also represent a model for a more general inter-organelle signalling network for functionally interconnecting different intracellular activities, a necessity for the maintenance of cellular homeostasis and to express harmonic global cellular responses
Review: Protein misfolding diseases – the rare case of Marinesco‐Sjögren syndrome
No full textSecretory and cell membrane proteins are synthesized in the endoplasmic reticulum (ER), where a network of molecular chaperones and folding factors ensure correct protein folding and export to post-ER compartments. Failure of this process leads to accumulation of unfolded/misfolded proteins, ER stress, and activation of the unfolded protein response (UPR), a complex signalling pathway aimed at restoring ER homeostasis, whose failure eventually leads to cell death. SIL1 is a nucleotide exchange factor for BiP, the main ER chaperone and primary sensor of ER stress. Loss of SIL1 function causes Marinesco-Sjögren syndrome (MSS), a rare multisystem disease of early infancy for which there is no cure. This review, examines the current understanding of SIL1 activities in the ER, and reviews experimental data describing the consequences of SIL1 deficiency in cell and animal models. We discuss the evidence supporting a role of the UPR -particularly the PERK branch - in the pathogenesis of MSS, and how this may be pharmacologically manipulated for treatment
Regulation of G protein-coupled receptor kinase subtypes in activated T lymphocytes. Selective increase of beta-adrenergic receptor kinase 1 and 2.
No full textOptical sensor using a floating body SOI MOSFET in the Delta-sigma loop
No full textIn this paper, the partially depleted SOI phototransistor has been used as a light intensity sensor. A pixel implementing the technique elaborated in [1] was designed and implemented on SOI technology. The circuit implements a first order Delta-sigma modulator. Measured data show flux densities as low as 3mW/m2 and an SNR of 60 dB. ©2008 IEEE.GR-KAEDLABEcole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, Export Date: 19 January 2010, Source: Scopus, Art. No.: 4656309, References: Harik, L., Sallese, J.-M., Kayal, M., Transient charge pumping as an efficient technique to measure low light intensity with PD SOI MOSFET Solid-State Electronics, , available online, in Press; J M. Hill and J. Lachman, A 900 MHz 2.25 MB cache with on chip CPU now in CU SOI, in ISSCC 2001, Session 11 SRAM 11.5Okhonin, S., Nagoga, M., Fazan, P., Principles of transient charge pumping on partially depleted SOI MOSFETs (2002) IEEE Electron Device Letters, 23, pp. 279-281. , Ma
Two isoforms of G protein-coupled receptor kinase 4 identified by molecular cloning
No full textUsing PCR we found that G protein-coupled receptor kinase4 (GRK4) mRNA is expressed only in brain out of several tissues tested. In the brain two amplification products were generated. Sequence analysis revealed that the two fragments differed only by the presence or absence of an in-frame-sequence of 96 bp/32 aminoacids, located near the N-terminal of the kinase. This demonstrates the existence of two isoforms of GRK4 which were named GRK4A and GRK4B in the presence or absence of the insert, respectively. This is the first evidence that, within the GRKs gene family, different isoforms do exist
Comparative analysis of beta-adrenergic receptor kinase and beta-arrestin mRNA expression in human cells.
No full textReceptor phosphorylation is a key step in the process of rapid desensitization. beta-Adrenergic receptor kinase is a specific receptor kinase that is known to phosphorylate and induce desensitization of several G-coupled synaptic receptors only when they are occupied by their agonists. We recently cloned human beta ARK cDNA and reported high levels of beta ARK expression in human peripheral blood leukocytes, also providing the first evidence for its possible functional role in these cells. Complete homologous receptor desensitization by beta ARK requires an additional cytosolic factor, called beta-arrestin. In the present study, we have cloned a 212 bp fragment of the human beta-arrestin cDNA to perform a comparative analysis of beta ARK and beta-arrestin mRNA expression in various human cell types. We found that also beta-arrestin mRNA is abundant in non-innervated tissues and cells. The fact that the entire machinery for G-coupled receptor desensitization is highly expressed in these cells further supports the idea that beta ARK may regulate nonsynaptic as well as synaptic receptors
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