A5081005463- Glycosylation and Glycoproteins Research
- Endoplasmic Reticulum Stress and Disease
- melanin and skin pigmentation
- Bone Tissue Engineering Materials
- Dental materials and restorations
- Galectins and Cancer Biology
- Immunotherapy and Immune Responses
- Cellular transport and secretion
- RNA regulation and disease
- Laser-Ablation Synthesis of Nanoparticles
- Dental Implant Techniques and Outcomes
- Monoclonal and Polyclonal Antibodies Research
- Carbohydrate Chemistry and Synthesis
- RNA and protein synthesis mechanisms
- Ion Channels and Receptors
- Toxin Mechanisms and Immunotoxins
- Melanoma and MAPK Pathways
- Biochemical Analysis and Sensing Techniques
- Pancreatic function and diabetes
- Autophagy in Disease and Therapy
- Chronic Lymphocytic Leukemia Research
- Cutaneous Melanoma Detection and Management
- Laser Applications in Dentistry and Medicine
- Nonlinear Optical Materials Studies
- Calcium signaling and nucleotide metabolism
University of Bucharest
2010-2025
Institute of Biochemistry
2015-2025
Romanian Academy
2013-2025
Universitatea Națională de Știință și Tehnologie Politehnica București
1992-2013
Yonsei University
2012
National Institute for Laser Plasma and Radiation Physics
2010
Institutul de Chimie Macromoleculară Petru Poni
2010
University of Oxford
1997-2001
National Institute of Research and Development for Technical Physics
2001
Gheorghe Asachi Technical University of Iași
1995
Ovarian cancer is the fourth most common in women Western world. In a pilot scale study, we highlight changes total serum glycome of patients with advanced ovarian that might shed insight into disease pathogenesis. These include increases levels core fucosylated, agalactosyl biantennary glycans (FA2) and sialyl Lewis x (SLex). To investigate further which proteins contribute to these alterations, developed technology analyze simultaneously glycosylation protein glycoforms contained single...
ABSTRACT Investigation of the entry pathways hepatitis B virus (HBV), a member family Hepadnaviridae , has been hampered by lack versatile in vitro infectivity models. Most concepts hepadnaviral infection come from more robust duck HBV system; however, whether two viruses use same mechanisms to invade target cells is still matter controversy. In this study, we investigate role an important plasma membrane component, caveolin-1 (Cav-1), infection. Caveolins are main structural components...
Synthesis of nanostructured thin films pure and oxidized levan exopolysaccharide by matrix-assisted pulsed laser evaporation is reported. Solutions exopolysaccharides in dimethyl sulfoxide were frozen liquid nitrogen to obtain solid cryogenic pellets that have been used as targets experiments with a KrF* excimer source. The expulsed material was collected assembled onto glass slides Si wafers. contact angle studies evidenced higher hydrophilic behavior the case structures because presence...
Hepatitis B virus (HBV) belongs to the Hepadnaviridae family of enveloped DNA viruses. It was previously shown that HBV can induce endoplasmic reticulum (ER) stress and activate IRE1-XBP1 pathway unfolded protein response (UPR), through expression viral regulatory X (HBx). However, it remained obscure whether or not this activation had any functional consequences on target genes UPR pathway. Of these targets, ER degradation-enhancing, mannosidase-like proteins (EDEMs) are thought play an...
Tyrosinase is a copper-containing enzyme that regulates melanin biosynthesis in mammals. Mutations at single N-glycosylation sequon of tyrosinase have been reported to be responsible for oculocutaneous albinism type IA humans, characterized by inactive and the total absence pigmentation. To probe role each site plays synthesis biologically active tyrosinase, we analyzed calnexin mediated folding mutants. We determined four six potential sites, including associated with albinism, are...
We have generated a database of 639 glycosidic linkage structures by an exhaustive survey the available crystallographic data for isolated oligosaccharides, glycoproteins, and glycan-binding proteins. For oligosaccharides there is relatively little available. A much larger number glycoprotein protein now been solved in which two or more linked monosaccharides can be resolved. In majority these cases, only few residues seen. Using structures, we identified one distinct conformers all...
Abstract In this work, an improved version of the radio frequency magnetron sputtering (RF‐MS) technique was used to prepare highly adherent B‐type carbonated hydroxylapatite (B‐CHA) thin films. Fourier transform infrared spectroscopy (FTIR) and grazing incidence X‐ray diffraction studies proved that coatings maintained composition revealed polycrystalline structure HA. Scanning electron microscopy analysis showed CHA films are rough exhibit a homogeneous microstructure. Energy‐dispersive...
Tyrosinase is the key enzyme in melanin biosynthesis, catalyzing multiple steps this pathway. The mature glycoprotein transported from Golgi to melanosome where biosynthesis occurs. In study, we have investigated effects of inhibitors N-glycan processing on synthesis, transport, and catalytic activity tyrosinase. When B16 mouse melanoma cells were cultured presence N-butyldeoxynojirimycin, an inhibitor endoplasmic reticulum-processing enzymes alpha-glucosidases I II, was synthesized but...
There is increased interest in smart bioactive materials to control tissue regeneration for the engineering of cell instructive scaffolds. We introduced combinatorial matrix-assisted pulsed laser evaporation (C-MAPLE) as a new method fabrication organic thin films with compositional gradient. Synchronized C-MAPLE levan and oxidized was employed assemble two-compound biopolymer film structure. The gradient composition validated by fluorescence microscopy. In this study, we investigated...
Melanoma is a form of skin cancer that can rapidly invade distant organs. A distinctive feature melanomas their pigmentation status, as melanin present in most melanomas, whilst many metastatic tumors could become amelanotic. Besides the obvious malfunction key genes pathway, amelanotic bear characteristic molecular signature accounting for aggressivity. Using mass spectrometry-based proteomics we report here panel biomarkers aggressive melanoma differ from less invasive pigmented cells. The...
EDEM1 is a mannosidase-like protein that recruits misfolded glycoproteins from the calnexin/calreticulin folding cycle to downstream endoplasmic reticulum associated degradation (ERAD) pathway. Here, we investigate role of in processing tyrosinase, tumour antigen overexpressed melanoma cells. First, analyzed and modeled major domains. The homology model raised on crystal structures human Saccharomyces cerevisiae ER class I α1,2-mannosidases reveals mannosidase domain located between...
We introduce a combinatorial approach for the fabrication of organic biopolymer thin films. Structures with compositional gradient are obtained by simultaneous laser vaporization two distinct targets. Matrix-assisted pulsed evaporation deposition method was applied to obtain library levan and oxidized in form film. The film composition structure demonstrated infrared spectroscopy while vitro cell culture assays illustrated characteristic responses cells specific surface regions. can rapidly...
Endoplasmic reticulum (ER)-associated degradation (ERAD) is the main mechanism of targeting ER proteins for to maintain homeostasis, and perturbations ERAD lead pathological conditions. ER-degradation enhancing α-mannosidase-like (EDEM1) was proposed extract terminally misfolded from calnexin folding cycle target them by ERAD. Here, using mass-spectrometry biochemical methods, we show that EDEM1 found in auto-regulatory complexes with components. Moreover, N-terminal disordered region...
In response to DNA-damaging physical or chemical agents, the DNA damage repair (DDR) pathway is activated in eukaryotic cells. radiobiology field, it important assess effect of a certain irradiation regime on cancer cells and compare non-transformed exposed identical conditions. The first step mechanism consists attachment proteins such as phosphorylated histone γ-H2AX (p-γ-H2AX) double-strand breaks (DSB) nucleus, which leads formation repairing foci. Therefore, imaging methods were...
Abstract Background Chronic hepatitis B virus (HBV) infection is a major risk for development of hepatocellular carcinoma (HCC), frequent malignancy with poor survival rate. HBV results in significant endoplasmic reticulum (ER) stress and activation the unfolded protein response (UPR) signaling, contributing factor to carcinogenesis. As part UPR, ER - associated degradation (ERAD) pathway responsible removing burden misfolded secretory proteins, re establish cellular homeostasis. Emerging...
The ERAD glycoprotein misfolding checkpoint complex de-mannosylates misfolded glycoproteins to enable retrotranslocation, ubiquitination, and proteasomal degradation. comprises an Endoplasmic Reticulum-Degradation Enhancing α-Mannosidase (EDEM) a Protein Disulfide Isomerase (PDI). We solved Cryo-EM structures of Chaetomium thermophilum ( Ct ) CtEDEM:CtPDI, both as the heterodimer with no client in α1-antitrypsin (A1AT-NHK). EDEM catalytic domain nests within PDI arc, while A1AT-NHK binds...
<title>Abstract</title> The ERAD glycoprotein misfolding checkpoint complex de-mannosylates misfolded glycoproteins targeting them to retrotranslocation, ubiquitination, and proteasomal degradation. comprises an Endoplasmic Reticulum-Degradation Enhancing α-Mannosidase (EDEM) a Protein Disulfide Isomerase (PDI). We solved Cryo-EM structures of the Chaetomium thermophilum (Ct) EDEM:PDI complex, both by itself in with classic substrate, α1-antitrypsin (A1AT-NHK). EDEM catalytic domain nestles...
G-protein coupled receptor 27 (GPR27) is part of the Super Conserved Receptors Expressed in Brain (SREB) family, alongside GPR85 and GPR173. While endogenous ligands functions SREB receptors are still unknown, GPR27 has been implicated insulin secretion tumorigenesis. Here, we show that substituting GPR27′ C-terminus domain with β-1 adrenergic (1AR) yields a chimera β-1AR-like ligand selectivity cellular functions. Interestingly, stimulation inhibited EGF-induced serum-responsive element...
In this study we have explored the endoplasmic reticulum associated events accompanying maturation of tyrosinase-related protein-1 (TRP-1) nascent chain synthesized in mouse melanoma cells. We show that TRP-1 folding process occurs much more rapidly than for tyrosinase, a highly homologous protein, being completed post-translationally by formation critical disulfide bonds. cells pretreated with dithiothreitol (DTT), unfolded is retained prolonged interaction calnexin and BiP before targeted...