selenoproteins in the endoplasmic reticulum

... types, including hepatocytes, to long-chain saturated fatty acids (SFAs) led to increased expression of proinflammatory cytokines, inhibition of insulin signaling, induction of endoplasmic reticulum ... TAG synthesis was initially hindered following stearate administration and was completely interrupted at longer incubation periods Interestingly, the interruption of TAG synthesis preceded the appearance ... also indicated by in vivo experiments using genetically modified mice bearing an inactivating mutation in the gene encoding the enzyme stearoyl-CoA desaturase This enzyme is responsible for the introduction...

Ngày tải lên: 14/02/2014, 22:20

... proceed in a vectorial, domainwise process from the N terminus to the C terminus Instead, folding occurs via intermediates with disulfide bridges involving distant parts of the protein In addition, the ... sorting in the Golgi, so that newly synthesized lysosomal enzymes appear in the medium In the case of mutants, the appearance in the medium is thus an indicator that the enzyme has left the ER In ... oligosaccharide Glucosidase II then removes the remaining terminal glucose with the consequence that newly synthesized proteins no longer bind to the lectins and leave the ER In case a protein is not folded...

Ngày tải lên: 07/03/2014, 17:20

... chain is brefeldin A-insensitive and is inhibited by the proteasome inhibitor clasto-lactacystin b-lactone, resulting in the accumulation of ricin A chains These stabilized ricin A chains are partly ... unfolded proteins in the endoplasmic reticulum Cell 101, 451–454 Patil C & Water P (2001) Intracellular signaling from the endoplasmic reticulum to the nucleus: the unfolded protein response in yeast ... were increased in the opaque mutants The transcriptional response in fl-2 may be induced by the UPR, as the change in the pattern of gene expression was restricted to the endosperm in which the...

Ngày tải lên: 16/03/2014, 11:20

... (basic-X-acidic-leucine) at the C-terminus, with the basic residue being lysine (21 species), arginine (nine) or histidine (four), and the acidic 1120 residue being glutamate (30) or aspartate (four) Murine ... (one)], in the second position [glycine (28), alanine (six), proline (one), methionine (one), arginine (one), or lysine (one)], or in both positions (24) The PGEL motif accounts for 21 of the 24 ... With the exception of the latter, these species, like all PGEL species, are mammals It should be noted that both proline (or methionine and phenylalanine) in the first position and glycine in the...

Ngày tải lên: 23/03/2014, 07:20

... stages of the infection, the envelope precursor gp160, through its high receptor binding affinity and inefficient vesicular transport [6], sequesters newly synthesized CD4 in the endoplasmic reticulum ... [20] The degradation of CD4 mediated by Vpu involves multiple steps that are initiated by the direct physical binding of Vpu to the cytoplasmic tail of CD4 in the ER [21] Although the binding ... link between the machinery responsible for the ubiquitination of proteins destined for degradation by the proteasome and the enhanced CD4 turnover in presence of Vpu Indeed, further lines of evidence...

Ngày tải lên: 13/08/2014, 05:22

... ubiquitinate and degrade misfolded proteins in the ER With the final destination of misfolded proteins known, another question remained Although the ERQC substrates are detected and retained in the ... polypeptide chain 1.2.1.1 The calnexin/calreticulin cycle As soon as the core Glc3Man9GlcNAc2 oligosaccharide is attached to the emerging polypeptide in the ER lumen, the protein enters the calnexin/calreticulin ... to the cysteine residue on the active site of E2 At the final step, the E3 ligase attaches ubiquitin to a lysine residue of the target protein In general, the E1-E2-E3 cascade is centered on the...

Ngày tải lên: 11/09/2015, 10:17

... reveal any alternative splicing in the ORF or in the 3¢ untranslated region (UTR) To explain the splice variants observed in the Northern blot we analysed the 5¢-UTR of the available several dozen ... present N terminal to the hydrophobic stretch but none on the C-terminal side, the first 38 amino acid residues are expected to be cytoplasmic, whereas the large C-terminal domain including the two ... and topology of the Hu-K4 protein In order to raise an antiserum against the Hu-K4 protein two rabbits were injected with a mixture of the two peptides underlined in Fig One of the rabbits produced...

Ngày tải lên: 19/02/2014, 17:20

... multi-spanning membrane protein, the seal would be provided in an alternating manner by either the nascent chain in the pore or, once the chain has left the pore, by the plug returning to the center of Sec61 ... transport across the ER membrane T A Rapoport the C-terminus can translocate across the channel, inserting the polypeptide as a loop, as in the case of a secretory protein Maintaining the permeability ... chain has left the pore The diameter of the pore ring, as observed in the crystal structure, has to increase during translocation, probably by movements of the helices to which the pore ring...

Ngày tải lên: 07/03/2014, 06:20

... aids, the assembly of other proteins, but is not part of the final assembly Later, the focus of chaperone research shifted to the role in the folding of single protein chains and in protecting the ... keeping newly synthesized proteins in a foldingcompetent state [10] Protein folding in the ER involves two additional features which distinguish the process from folding in the cytosol: disulfide ... link the ‘monomers’ into ‘hexamers’ In the ‘monomer’, the heavy and light chains are coupled via an interchain disulfide bond between the two constant domains, and the two heavy chains are linked...

Ngày tải lên: 07/03/2014, 06:20

... staining of cells expressing CD4–TMD ⁄ CTser in the absence of detergent (Fig 3B) Together, these results indicated that although the dilysine KSKTH motif of the TMD ⁄ CT domain plays a role in ... reticular staining pattern and colocalized with the ER marker protein, calnexin (Fig 4B) Taken together, these data indicated that the TMD domain of UGT1A was sufficient to retain the ectodomain of CD4 ... Indeed, the CD4–TMD26 staining pattern overlapped with the ER and Golgi markers, calnexin and GM130, respectively (Fig 5B) In the case of CD4–TMD21, staining was observed in both the ER and the...

Ngày tải lên: 07/03/2014, 16:20

... resulting in the formation of tubular invaginations that facilitate internalization [21] It remains to be determined whether this toxin-induced pathway or clathrinmediated endocytosis is predominant ... of the endosomes, but remained in the perinuclear region After 30 min, StxB appeared to co-localize with Tfn in the majority of cells However, after 60 min, StxB separated into another perinuclear ... toxicity in the monocyte-derived macrophages may paradoxically result from the inability of the cell to transport toxin out of the endosomes and into the Golgi (provided that the toxin would then...

Ngày tải lên: 16/03/2014, 04:20

... staining was evident in resting cells (Fig 3A) Following stimulation with A23187, the intensity of staining of the nuclear membrane in digitonin-permeabilized cells was lower than that seen in ... structures resembling the Golgi, with very little staining in the region of the nuclear membrane In addition, a highly punctate staining pattern throughout the cytosol and nucleus of a resting cell was ... where they were shown to interact with caveolin-1A [45] Following this, we examined the localization of annexin V, annexin I, p11, vimentin, actin and caveo1283 cPLA2-a localization in endothelial...

Ngày tải lên: 16/03/2014, 18:20

... domains, the M-domain and the NG-domain The Mdomain (methionine-rich domain) associates with SRP RNA and provides the SS-binding site, and the NGdomain is responsible for GTP binding (G-domain) ... During this process, the permeability barrier is kept by the coordinated in and out movement of the ‘plug’ and the widening ⁄ narrowing of the hydrophobic ring, while the opening ⁄ closing of the ... (i.e the ribosome in the cotranslational pathway) Either this contact or the presence of the SS triggers the widening of the cytosolic side of the channel [25], including the hydropho˚ bic ring,...

Ngày tải lên: 22/03/2014, 15:21

... distinct but related routes by which a ligand might traffic from the plasma membrane to the endoplasmic reticulum; one involving transport through the Golgi, and the other not involving the Golgi ... organelle that contains input SV40 Second, the simultaneous co localization of SV40 with both β-COP and caveolin-1 is seen before the virus appears in the ER [9] Thus, the β-COP-containing intermediate ... nm) invaginations of the plasma membrane that are distinguished from clathrincoated pits by their size, distinctive flask-like shape, and lack of a visible coat in thin sections Expression of the...

Ngày tải lên: 20/06/2014, 04:20

... [9,10] Beclin 1, a class III phosphatidylinositol 3-kinaseinteracting protein [11], plays a role in promoting autophagy [12] Beclin contains a Bcl-2-binding domain which may serve as a point of cross-talk ... -XL-binding domain We next investigated the control of Beclin and its binding partner, Bcl-2, on autophagic activity Beclin was the first mammalian protein described to mediate autophagy [12] Beclin ... H+-ATPase inhibitor) to inhibit autophagosome–lysosome fusion [24], and E64d (5 lgÆmL)1, inhibitor of cysteine proteases, including cathepsin B), and PepA (5 lgÆmL)1, cathepsin D inhibitor) to inhibit...

Ngày tải lên: 07/03/2014, 09:20

... Proteins in every other fraction were analyzed by Western blotting with the anti-H-chain, the anti-L-chain, the anti-L28, the anti-Nd-sD, the anti-fhx/P25 or the anti-calnexin-peptide Igs (C) The ... [1] The disulfide linkage between H- and L-chains is not formed in Nd-s and Nd-sD mutants because of the lack of Cys-172 in the mutant L-chain [8] It is of interest to note that the fhx/P25 in the ... a1,2-mannosidases to yield only the 27-kDa molecule in the secreted fibroin In order to examine a role of L-chain in the protection of a1,2-mannose residues of fhx/P25 in the elementary unit, the Nd-sD mutant...

Ngày tải lên: 16/03/2014, 16:20

... processing enzymes, the same experiment was performed in the presence of kifunensine, an inhibitor of the demannosylation process Figure 1D,H shows that incubation in the presence of 20 lM kifunensine ... only originate from the action of UGGT Furthermore, when the incubation was performed in the presence of 20 lM kifunensine, the formation of Man4GlcNAc2 and Man8GlcNAc2 species was strongly inhibited ... converted into Man4GlcNAc2, in contrast with the small amount of Man6GlcNAc2 originating from the Man9GlcNAc2 species ERAD of glycoproteins bearing Man5 and Man9 populations in MI8-5 cells The N-glycosylation...

Ngày tải lên: 16/03/2014, 16:20

... conformational change in the peptide-binding domain Apparently, in the in vitro analysis in the absence of 5184 polypeptide substrates, this leads to reversible trapping of the J-domain or neighboring parts ... ERj5 or their J-domains, such as in the case of ERj2 ⁄ Sec63, are in the low millimolar range Furthermore, the total amounts of Hsp70 and Hsp40 proteins in the ER lumen (Table 1) and the observed ... substrates Proteins with BiP-reactive J-domains have a high affinity for BiP–ATP and can therefore bind to the underside of the ATP-binding cleft Owing to their additional domains, the Hsp40s ERj3,...

Ngày tải lên: 30/03/2014, 03:20

... kinectin and EF-1γ binding domain on EF-1δ 161 5.7 Kinectin anchors the EF-1 subunits to the ER 166 5.8 Aberrant splicing of EF-1δ binding domain on kinectin mRNA 171 using morpholinos 5.9 Kinectin ... conventional kinesin (Kifs 5) using in vitro and in vivo assays (Ong et al., 2000) The kinesin-binding domain on kinectin can enhance the microtubule-stimulated ATPase activity and inhibit the kinesin-dependent ... based on the position of the motor domain, namely, N-kinesin with motor domain at amino terminal; M-kinesin with motor domain in the middle and C-kinesin with motor domain at the COOH terminal (Miki...

Ngày tải lên: 12/09/2015, 10:00

... on the endogenous kinectin protein level iv Fig 3.2 Kinectin knockdown using RNAi inhibited the migration of HeLa cells in wound healing assays Fig 3.3 The disruption of kinesin-kinectin interaction ... stained with anti-kinectin antibodies However, kinectin was not found in the axons where kinesin was detected (Hollenbeck, 1989; Niclas et al., 1994) ER TM Int1 Int2 Int3 Int4 Int5 Kinectin Fig ... However, the double immuno-staining shows kinesin and kinectin only co-localize with melanosomes in the perinuclear area, which suggest that kinesin-kinectin interaction based motor transport is involved...

Ngày tải lên: 08/11/2015, 16:45