FEBS Journal
1742-464X
1432-1033
Anh Quốc
Cơ quản chủ quản: Wiley-Blackwell Publishing Ltd , WILEY
Lĩnh vực:
Cell BiologyMolecular BiologyBiochemistry
Phân tích ảnh hưởng
Thông tin về tạp chí
The FEBS Journal is an international peer-reviewed Journal devoted to publication of high-quality papers reporting significant advances in the molecular life sciences. Acceptance decisions are based on the originality and quality of the research and its prospective interest to a wide readership. Papers submitted to The FEBS Journal should provide novel perspectives on a biologically relevant problem and be of interest to a broad readership. The scope of the Journal is broad and inclusive. We are particularly interested in papers in which state-of-the-art approaches are applied to bring novel insight into molecular and cellular mechanisms that underlie the functions of molecules, cells and organisms. The Journal also welcomes manuscripts of an interdisciplinary nature, including systems approaches that address fundamental concepts in molecular, cellular or organismal biology. The Journal does not accept papers that lack biological insight. Papers describing bioinformatic analysis, modelling or structural studies of specific systems or molecules should include experimental data. The FEBS Journal also publishes Reviews, Minireviews, Viewpoints and Snapshots on a wide range of topics. These pieces are specially commissioned by our Editorial team and are selected on the basis of their interest to a wide readership. In addition, the Journal publishes Special Issues that provide detailed insight into a specific scientific field.
Các bài báo tiêu biểu
What distinguishes GroEL substrates from other <i>Escherichia coli</i> proteins? Experimental studies and theoretical considerations have shown that only a small subset of Escherichia coli proteins fold in vivo with the help of the GroE chaperone system. These proteins, termed GroE substrates, have been divided into three classes: (a) proteins that can fold independently, but are found to associate with GroEL; (b) proteins that require GroE when the cell is under stress; and (c) ‘obligatory’ proteins that require GroE assistance even under normal conditions. It remains unclear, however, why some proteins need GroE and others do not. Here, we review experimental and computational studies that addressed this question by comparing the sequences and structural, biophysical and evolutionary properties of GroE substrates with those of nonsubstrates. In general, obligatory substrates are found to have lower folding propensities and be more aggregation prone. GroE substrates are also more conserved than other proteins and tend to utilize more optimal codons, but this latter feature is less apparent for obligatory substrates. There is no evidence, however, for any specific sequence signatures although there is a tendency for sequence periodicity. Our review shows that reliable sequence‐ or structure‐based predictions of GroE dependency remain a challenge. We suggest that the different classes of GroE substrates be studied separately and that proper control test sets (e.g. TIM barrel proteins that need GroE for folding versus TIM barrels that fold independently) be used more extensively in such studies.
Tập 279 Số 4 - Trang 543-550 - 2012
Primary Structure of EPV20, a Secretory Glycoprotein Containing a Previously Uncharacterized Type of Domain A 20‐kDa glycoprotein, EPV20, was isolated from bovine milk and characterized. The primary structure was determined by cDNA and protein sequencing combined with mass spectrometry. EPV20 is a 130‐residue polypeptide synthesized with a 19‐residue signal peptide. The function of EPV20 is unknown, but it displays 79% sequence similarity to a putative protein deduced from a human testis cDNA sequence designated HE1 (human epididymis clone 1) (Kirchhoff, C., 1992. EMBL/GeneBank/DDBJ Databases, accession number X6769X). Northern blot analysis showed the bovine EPV20 to be expressed in kidney, spleen, liver and mammary gland, but remarkably not in bovine testis. The six Cys residues of EPV20 were found to be disulfide‐linked in a 1–6, 2–3 and 4–5 pattern. This disulfide arrangement has been observed in other proteins, e.g. in human prostatic acid phosphatase, but the spacing between the cystines differs. Therefore, EPV20 represents a new structure among the large group of proteins containing domains with three disulfide bonds.
Tập 243 Số 1-2 - Trang 437-441 - 1997
High‐Level Expression of Recombinant Pea Chloroplast Fructose‐1,6‐Bisphosphatase and Mutagenesis of Its Regulatory Site The cDNA fragment coding for mature chloroplast pea fructose‐1,6‐bisphosphatase [Fru(1,6)P 2 ase] was introduced by PCR into the expression vector pET‐3d resulting in the construction pET‐FBP. After transformation of BL21(DE3) Escherichia coli cells by the pET‐FBP plasmid and induction with isopropyl thio‐β‐d ‐galactoside, high‐level expression of the recombinant enzyme was achieved. The protein could be purified in three days by a simple procedure which includes heat treatment, ammonium sulfate fractionation, DEAE Sephacel and ACA 44 chromatographies with a yield of 20 mg/l culture. In every respect, the recombinant enzyme was similar to plant chloroplast Fru(1,6)P 2 ase and, in particular, its reactivity with Mg2+ and redox regulatory properties were conserved. In a second series of experiments based on three‐dimensional modeling of the chloroplast protein and sequence alignments, two cysteine residues of the recombinant enzyme (Cys173 and Cys178) were mutated into serine residues. An active enzyme, which did not respond to thiol reagents and to light activation, was obtained, confirming the putative regulatory role of the insertional sequence characteristic of the chloroplast enzyme.
Tập 229 Số 3 - Trang 675-681 - 1995
Physiological functions of thioredoxin and thioredoxin reductase Thioredoxin, thioredoxin reductase and NADPH, the thioredoxin system, is ubiquitous from Archea to man. Thioredoxins, with a dithiol/disulfide active site (CGPC) are the major cellular protein disulfide reductases; they therefore also serve as electron donors for enzymes such as ribonucleotide reductases, thioredoxin peroxidases (peroxiredoxins) and methionine sulfoxide reductases. Glutaredoxins catalyze glutathione‐disulfide oxidoreductions overlapping the functions of thioredoxins and using electrons from NADPH via glutathione reductase. Thioredoxin isoforms are present in most organisms and mitochondria have a separate thioredoxin system. Plants have chloroplast thioredoxins, which via ferredoxin–thioredoxin reductase regulates photosynthetic enzymes by light. Thioredoxins are critical for redox regulation of protein function and signaling via thiol redox control. A growing number of transcription factors including NF‐κB or the Ref‐1‐dependent AP1 require thioredoxin reduction for DNA binding. The cytosolic mammalian thioredoxin, lack of which is embryonically lethal, has numerous functions in defense against oxidative stress, control of growth and apoptosis, but is also secreted and has co‐cytokine and chemokine activities. Thioredoxin reductase is a specific dimeric 70‐kDa flavoprotein in bacteria, fungi and plants with a redox active site disulfide/dithiol. In contrast, thioredoxin reductases of higher eukaryotes are larger (112–130 kDa), selenium‐dependent dimeric flavoproteins with a broad substrate specificity that also reduce nondisulfide substrates such as hydroperoxides, vitamin C or selenite. All mammalian thioredoxin reductase isozymes are homologous to glutathione reductase and contain a conserved C‐terminal elongation with a cysteine–selenocysteine sequence forming a redox‐active selenenylsulfide/selenolthiol active site and are inhibited by goldthioglucose (aurothioglucose) and other clinically used drugs.
Tập 267 Số 20 - Trang 6102-6109 - 2000
Isolation and characterization of a thioredoxin‐dependent peroxidase from <i>Chlamydomonas reinhardtii</i> All living organisms contain redox systems involving thioredoxins (Trx), proteins featuring an extremely conserved and reactive active site that perform thiol‐disulfide interchanges with disulfide bridges of target proteins. In photosynthetic organisms, numerous isoforms of Trx coexist, as revealed by sequencing of Arabidopsis genome. The specific functions of many of them are still unknown. In an attempt to find new molecular targets of Trx in Chlamydomonas reinhardtii , an affinity column carrying a cytosolic Trx h mutated at the less reactive cysteine of its active site was used to trap Chlamydomonas proteins that form mixed disulfides with Trx. The major protein bound to the column was identified by amino‐acid sequencing and mass spectrometry as a thioredoxin‐dependent 2Cys peroxidase. Isolation and sequencing of its gene revealed that this peroxidase is most likely a chloroplast protein with a high homology to plant 2Cys peroxiredoxins. It is shown that the Chlamydomonas peroxiredoxin (Ch‐Prx1) is active with various thioredoxin isoforms, functions as an antioxidant toward reactive oxygen species (ROS), and protects DNA against ROS‐induced degradation. Expression of the peroxidase gene in Chlamydomonas was found to be regulated by light, oxygen concentration, and redox state. The data suggest a role for␣the Chlamydomonas Prx in ROS detoxification in the chloroplast.
Tập 269 Số 1 - Trang 272-282 - 2002
The Subunit Structure of Rabbit‐Skeletal‐Muscle Phosphorylase Kinase, and the Molecular Basis of Its Activation Reactions Phosphorylase kinase was isolated from rabbit skeletal muscle in a state approaching homogeneity as judged by the criteria of ultracentrifugal analysis, ion‐exchange chromatography, and antigen‐antibody precipitation in agar. The purified enzyme showed four protein‐staining components upon acrylamide gel electrophoresis in the presence of sodium dodecylsulphate, termed α, α′, β and γ. A variety of precautions designed to eliminate the possible action of proteases and ensure complete reduction and denaturation of the protein had no influence on the gel pattern. The molecular weights of the four components determined by gel electrophoresis, and supported by sedimentation equilibrium in the presence of 6 M guanidinium chloride, following partial separation of the chains by gel filtration on Sephadex G‐200 in the presence of sodium dodecylsulphate, were:–α= 145000, α′= 140000, β= 128000 and γ= 45000. The α' component was present only in trace amounts and the evidence suggests it may be derived from the α component. The three subunits α, β, and γ, were found to exist in equimolar quantities by densitometric analysis of acrylamide gels, by gel filtration on Sephadex G‐200 in the presence of sodium dodecylsulphate, and by carboxymethylation with iodo[14 C]acetate, suggesting a minimal binding molecular weight, αβγ, of 318000. The molecular weight of the native enzyme was determined as 1.28 × 106 , demonstrating that phosphorylase kinase is composed of 4.0 αβγ units. Activation of the enzyme by incubation with adenosine‐3′:5′‐phosphate‐dependent protein kinase, adenosine 3′:5′‐phosphate and Mg‐ATP, was accompanied by the phosphorylation of one site on the β subunit, although a second site on the α subunit was phosphorylated at a slower rate. Activation of the enzyme by proteolysis resulted from a limited cleavage of the α subunit. The products of proteolytic attack suggest that the α and β subunits may be structurally related. The γ subunit was not phosphorylated, was resistant to proteolysis and distinct from the (α+β) subunits in its amino acid composition. The possible functions of the chains, and the implications of the activation reactions to the nervous and hormonal control of glycogenolysis in vivo are discussed.
Tập 34 Số 1 - Trang 1-14 - 1973
Changes in glycosaminoglycan structure and composition of the main heparan sulphate proteoglycan from human colon carcinoma cells (perlecan) during cell differentiation Colon carcinoma cells provide a useful model to study the biochemical processes associated with cell differentiation. Undifferentiated HT29, differentiated HT29MTX−3 and HT29MTX−6 , and Caco2 human colon carcinoma cells have been used to study the production of proteoglycans and to characterize the glycosaminoglycan structure of the heparan sulphate chains. All the cell lines produce mainly a heparan sulphate proteoglycan that is found partly in the extracellular medium and associated to the cell membrane. The heparan sulphate proteoglycans from the media were purified by ion‐exchange chromatography and subjected to structural analysis. The heparan sulphate proteoglycan from differentiated cells is larger and more homogeneous in size than the heparan sulphate proteoglycan from undifferentiated HT29 cells. No differences in protein core structure were observed when cells were labeled with [35 S]methionine and the protein cores visualized by gel electrophoresis. Nevertheless, differences in glycosaminoglycan composition were found correlated with the degree of differentiation. The heparan sulphate chains from differentiated HT29MTX−3 and HT29MTX−6 cells have a higher sulphation degree than those from undifferentiated HT29 cells. The heparan sulphate from Caco2 cells is the most highly sulphated species. The differences are mainly attributed to O‐sulphate groups. The increase in O‐sulphation was more pronounced for
D ‐glucosamine 6‐O ‐sulphate than for
L ‐iduronic acid 2‐O ‐sulphate groups.
Tập 254 Số 2 - Trang 371-377 - 1998
Molecular cloning and sequence analysis of bovine lactotransferrin The screening of a bovine submaxillary gland cDNA library yielded 25 clones coding for bovine lactotransferrin. The nucleotide sequence of the longest insert contained a protein‐coding region of 2115 nucleotides and a 3′ non‐coding region of 194 nucleotides followed by a poly(A) tract of about 55 nucleotides. The predicted peptide sequence included a 16‐amino‐acid signal sequence upstream of the first amino acid of the native protein. The identity of the clone was confirmed by matching the amino acid sequence predicted from the cDNA with the N‐terminal and tryptic peptide sequences derived from purified bovine milk lactotransferrin, and also by similarity with human and murine lactotransferrins. The cDNA described corresponds to a 705‐amino‐acid‐long preprotein that lacks the start methionine. The sequence of the secreted protein is 689 amino acids long and contains five potential glycosylation sites. Bovine lactotransferrin is 69% and 64% identical to human and murine lactotransferrins, respectively.
Tập 196 Số 1 - Trang 177-184 - 1991
Expression of human lactotransferrin receptors in phytohemagglutinin‐stimulated human peripheral blood lymphocytes In the resting rate, the human peripheral blood lymphocytes did not show detectable surface and intracellular receptors for human lactotransferrin. However, both types of lactotransferrin receptors were expressed during stimulation of lymphocytes with phytohemagglutinin. The appearance of receptors was time‐dependent and the number of receptors reached a plateau after at least two days of mitogen stimulation. These results suggest that the presence of surface receptors on mitogen‐stimulated lymphocytes is not consecutive to a modification of subcellular distribution but to an induction of biosynthesis of the receptors. As measured by incorporation of [3 H]thymidine into DNA, addition of human lactotransferrin in a serum‐free medium increased the proliferative activity of phytohemagglutinin‐stimulated lymphocytes. Optimal enhancement of [3 H]thymidine incorporation was obtained by adding 30% iron‐saturated lactotransferrin at a concentration of 0.17 μM. Therefore, the role of lactotransferrin in the response of lymphocytes to mitogen stimulation appears to be similar to that previously described for serotransferrin. The lactotransferrin receptor was visualized using 125 I‐labeled lactotransferrin on nitrocellulose paper after electroblotting of the Triton X‐100 extract of the phytohemagglutinin‐stimulated lymphocytes as two protein bands of 100 and 110 kDa molecular mass. Purification of the lactotransferrin receptor from the Triton‐X‐100‐soluble extract of stimulated lymphocytes was performed by antiligand‐affinity chromatography. The binding of lactotransferrin to the purified receptors was reversible and dependent on concentration and pH.
Tập 179 Số 2 - Trang 481-487 - 1989
Human lactotransferrin: amino acid sequence and structural comparisons with other transferrins
Tập 145 Số 3 - Trang 659-676 - 1984