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Protein
& Peptide Letters
ISSN: 0929-8665
Protein &
Peptide Letters
Volume 16, Number 6, 2009
Contents
Prelude; Cellular Mechanics
Guest Editor: Yusuf Tutar
Editorial Pp.
570
[PMID:
19519513 PubMed - indexed for MEDLINE]
Hsp70 Structure, Function, Regulation and Influence on Yeast
Prions Pp. 571-581
D. Sharma and D.C. Masison
[Abstract] [Purchase
Article]
[PMID:
19519514 PubMed - indexed for MEDLINE]
Influence of Hsp70 Chaperone Machinery
on Yeast Prion Propagation Pp. 582-586
E. Guinan and G.W. Jones
[Abstract] [Purchase
Article]
[PMID:
19519515 PubMed - indexed for MEDLINE]
Remodeling of Protein Aggregates by Hsp104
Pp. 587-597
J.R. Glover and R. Lum
[Abstract] [Purchase
Article]
[PMID:
19519516 PubMed - indexed for MEDLINE]
Hsp104 and Prion Propagation Pp.
598-605
N.V. Romanova and Y.O. Chernoff
[Abstract] [Purchase
Article]
[PMID:
19519517 PubMed - indexed for MEDLINE]
Heat Shock Protein 40: Structural Studies
and Their Functional Implications Pp. 606-612
J. Li, X. Qian and B. Sha
[Abstract] [Purchase
Article]
[PMID:
19519518 PubMed - indexed for MEDLINE]
Essential Structural and Functional Features
of Small Heat Shock Proteins in Molecular Chaperoning Process
Pp. 613-622
S. Kocabiyik
[Abstract] [Purchase
Article]
[PMID:
19519519 PubMed - indexed for MEDLINE]
Structural and Functional Diversity Among Eukaryotic
Hsp70 Nucleotide Exchange Factors Pp. 623-630
M. Kabani
[Abstract] [Purchase
Article]
[PMID:
19519520 PubMed - indexed for MEDLINE]
Tethering Creates Unusual Kinetics for
Ribosome-Associated Chaperones with Nascent Chains Pp.
631-634
S.N. Witt
[Abstract] [Purchase
Article]
[PMID:
19519521 PubMed - indexed for MEDLINE]
Application of GFP-Labeling to Study
Prions in Yeast Pp. 635-641
L.E. Greene, Y.-N. Park, D.C. Masison and
E. Eisenberg
[Abstract] [Purchase
Article]
[PMID:
19519522 PubMed - indexed for MEDLINE]
A Unique Mechanism of Chaperone Action:
Heme Regulation of Hap1 Activity Involves Separate Control
of Repression and Activation Pp. 642-649
H.C. Lee and L. Zhang
[Abstract] [Purchase
Article]
[PMID:
19519523 PubMed - indexed for MEDLINE]
General Articles
Regular Papers
Reduced NGF Secretion by HT-29 Human Colon
Cancer Cells Treated with a GRPR Antagonist Pp.
650-652
C.B. de Farias, L. Stertz, R.C. Lima, F.
Kapczinski, G. Schwartsmann and R. Roesler
[Abstract] [Purchase
Article]
[PMID:
19519524 PubMed - indexed for MEDLINE]
Inhibitory Effects of β-Cyclodextrin
and Trehalose on Nanofibril and AGE Formation During Glycation
of Human Serum Albumin Pp. 653-659
E. Sharifi, N. Sattarahmady, M. Habibi-Rezaei,
M. Farhadi, N. Sheibani, F. Ahmad and A.A. Moosavi-Movahedi
[Abstract] [Purchase
Article]
[PMID:
19519525 PubMed - indexed for MEDLINE]
Identification of a Molten Globule Like
State in HC-N Fragment of
Botulinum Neurotoxin A: Shedding Light on the Poorly Known
Features of a Conserved Sub-Domain Pp. 660-663
L. Hasani, B. Ranjbar, M. Tavallaie and
M. Sadeghizadeh
[Abstract] [Purchase
Article]
[PMID:
19519526 PubMed - indexed for MEDLINE]
Protein Engineering of a Fibroblast Growth
Factor 2 Protein for Targeting to Bone Mineral Hydroxyapatite
Pp. 664-667
E. Jeon and J.-H. Jang
[Abstract] [Purchase
Article]
[PMID:
19519527 PubMed - indexed for MEDLINE]
Efficient Production of Human β-Defensin
2 (HBD2) in Escherichia coli Pp. 668-676
T. Vargues, G.J. Morrison, E.S. Seo, D.J.
Clarke, H.L. Fielder, J. Bennani, U. Pathania, F. Kilanowski,
J.R. Dorin, J.R.W. Govan, C.L. Mackay, D. Uhrín and
D.J. Campopiano
[Abstract] [Purchase
Article]
[PMID:
19519528 PubMed - indexed for MEDLINE]
Glycan-Binding Profile and Cell Adhesion
Activity of American Bullfrog (Rana catesbeiana)
Oocyte Galectin-1 Pp. 677-684
S.M.A. Kawsar, R. Matsumoto, Y. Fujii, H.
Yasumitsu, H. Uchiyama, M. Hosono, K. Nitta, J. Hamako, T.
Matsui, N. Kojima and Y. Ozeki
[Abstract] [Purchase
Article]
[PMID:
19519529 PubMed - indexed for MEDLINE]
Proteome Analysis of Rice Root Plasma
Membrane and Detection of Cold Stress Responsive Proteins
Pp. 685-697
M. Hashimoto, M. Toorchi, K. Matsushita,
Y. Iwasaki and S. Komatsu
[Abstract] [Purchase
Article]
[PMID:
19519530 PubMed - indexed for MEDLINE]
Exploring Rat Plasmatic Proteomes: What
Triggered the Liver Regeneration? Pp. 698-705
X.Y. Deng, W.R. Li, Y.W. Sun, H.D. Wei,
Y. Jiang and F.C. He
[Abstract] [Purchase
Article]
[PMID:
19519531 PubMed - indexed for MEDLINE]
New Approach to Achieve High-Level Secretory
Expression of Heterologous Proteins by Using Tat Signal Peptide
Pp. 706-710
Y.-D. Li, Z. Zhou, L.-X. Lv, X.-P. Hou and
Y.-Q. Li
[Abstract] [Purchase
Article] [PMID:
19519532 PubMed - indexed for MEDLINE]
Abstracts
[Back to top]
[PMID:
19519513 PubMed - indexed for MEDLINE]
Editorial:
Machines in disrepair can either be fixed by mechanics
or if they are completely damaged, they end up in a dumpster
site. Proteins are machinery for function of an organism and
must be strictly controlled for proper function. Heat shock
proteins (Hsps) are the mechanics of almost all living organisms.
By the same analogy, Hsps either help misfolded substrate
proteins to reach their native conformation or send them for
degradation [1]. Hsps function in a wide range of cellular
processes; however their ultimate funct ion is to keep the
proteins in the native conformation [1, 2]. Unfolded or partially
folded proteins must reach a global free energy minimum to
fold to their native state. The crowded molecular environment
in a cell and hydrophobic environment of newly synthesized
protein may cause protein aggregation, undesired interactions,
and failure of assembling multi protein complexes [3]. Both
prokaryotic and eukaryotic cells adapted a strategy to solve
these problems; expressing heat shock proteins or so called
“cellular mechanics”. Proposed models suggest
that Hsp70s, Hsp40s and Hsp104 dissolve protein aggregates
by acting together; therefore, emphasis was given on these
proteins [3-5]. Hsp70 and Hsp104 were commonly studied in
yeast, therefore Hsp70 and Hsp104 were further reviewed in
S. cerevesiae by Dr. Jones and Dr. Chernoff, respectively.
Several other Hsps are involved during substrate protein folding
and prevention of aggregation. Because of their excessive
number, these other proteins were not reviewed under separate
topics but included under current topics. Hsp70 proteins interact
with different Hsp40s to form a specialized function. Therefore,
Hsp70 serves at a variety of cellular function. For this purpose,
two leading groups working towards Hsp70 were invited to write
reviews by emphasizing different aspects. The review by Dr.
Jones specially focuses on yeast prions. The other review
by Dr. Masison highlights structure-function relationship
of Hsp70, Hsp70 interaction with other proteins, and Hsp70
role in signal transduction and apoptosis.
Intensive research has been done on dissolving mechanism of
the aggregates by heat shock proteins and Hsp70 is at the
heart of this network. Hsp100 family chops off aggregates
to facilitate Hsp70-Hsp40 complex function. Hsp104 chaperone
role in interactions with aggregates and with Hsp70-Hsp40
complex in yeast was reviewed by Dr. Chernoff. Unique structure
of Hsp100 serves to separate chunks from aggregates. Further
biological functions of Hsp104, and structure of Hsp104 were
reviewed by Dr. Glover.
Hsp40 picks an unfolded protein and submits it to Hsp70. Hsp70
processes the unfolded substrate by providing a hydrophobic
space. This allows a protein to fold to its native structure
and makes an nonfunctional protein functional. Dr. Sha’s
group presented Hsp40 and its interaction with Hsp70. Classification
and structure of Hsp40s were discussed in detail in order
to better understand the folding of substrate peptides and
solubilisation of aggregates.
Throughout this mechanism new proteins were discovered, small
Hsps and nucleotide exchange factors. Dr. Kocabiyik discusses
small Hsps and their essential role for inhibiting aggregate
formation. In the next review, Dr. Kabani provides an overview
on nucleotide exchange factors. Hsp70 encapsulates and releases
substrate proteins by coupling ATP hydrolysis energy. However
to start the second round, hydrolyzed ATP must be removed
from Hsp70 so that another ATP can bind. Nucleotide exchange
factors replace ATP for ADP in Hsp70. Detailed information
on nucleotide exchange factors are given in the review.
Ribosome associated chaperones are unique because they draw
less attention compared to the other cellular isoforms. However,
these types of chaperones help folding of newly synthesized
proteins properly. The subject is reviewed by Dr. Witt.
Studying with Green Florescent Protein labeling is a novel
method to monitor prion propagation and prion curing. Dr.
Greene reviewed recent advances and application of this peculiar
technique and compares the technique with other traditional
methods.
Heat shock proteins maintain cellular function through keeping
proteins in their native state; however this is not their
sole function. Dr. Zhang reviews Hsp70-Hsp90 molecular chaperones
role in transcription activation of several genes along with
Hap1, the yeast heme activator protein. This review of Hsps
involvement in different metabolic process explains their
vital roles in metabolism.
REFERENCES
[1] Tutar, Y.; Song, Y.; Masison D.C. Primate chaperones Hsc70
(constitutive) and Hsp70 (induced) differ functionally in
supporting growth and prion propagation in Saccharomyces
cerevisiae. Genetics, 2006, 172,
851-861.
[2] Song, Y.; Wu, Y.X.; Jung, G.; Tutar, Y.; Eisenburg, E.;
Masison, D.C. Role for Hsp70 chaperone in Saccharomyces cerevisiae
prion seed replication. Eukaryot. Cell, 2005,
2, 289-297.
[3] Tutar, Y. Heat shock proteins, substrate specificity and
modulation of function. Protein Pept. Lett., 2006,
13, 699-705.
[4] Tutar, Y. Key residues involved in Hsp70 regulatory activity
and affect of co-chaperones on mechanism of action. Protein
Pept. Lett., 2006, 13, 693-698.
[5] Tutar, L.; Tutar, Y. Ydj1 but not Sis1 stabilizes Hsp70
protein under prolonged stress in vitro. Biopolymers,
2008, 89, 171.
Dr. Yusuf Tutar
Guest Editor
Protein &
Peptide Letters
Department of Chemistry, Biochemistry Division
Cumhuriyet University
58140 Sivas
Turkey
E-mails: ytutar@cumhuriyet.edu.tr
ytutar@yahoo.com
[Back to top]
[Purchase
Article] [PMID:
19519514 PubMed - indexed for MEDLINE]
Hsp70 Structure, Function, Regulation and Influence on
Yeast Prions
D. Sharma and D.C. Masison
Heat shock proteins protect cells from various conditions
of stress. Hsp70, the most ubiquitous and highly conserved
Hsp, helps proteins adopt native conformation or regain function
after misfolding. Various co-chaperones specify Hsp70 function
and broaden its substrate range. We discuss Hsp70 structure
and function, regulation by co-factors and influence on propagation
of yeast prions.
[Back to top]
[Purchase
Article] [PMID:
19519515 PubMed - indexed for MEDLINE]
Influence of Hsp70 Chaperone Machinery on Yeast Prion
Propagation
E. Guinan and G.W. Jones
Chaperones have long been recognised for their essential
roles in the cell. They are involved in the refolding or degradation
of misfolded proteins as well as the correct folding of newly
synthesised proteins. However recent experiments have discovered
that chaperones also have an important role to play in the
propagation and maintenance of prions in yeast. The following
minireview focuses on the Hsp70 chaperone family and it’s
involvement in the propagation of yeast prions.
[Back to top]
[Purchase
Article] [PMID:
19519516 PubMed - indexed for MEDLINE]
Remodeling of Protein Aggregates by Hsp104
J.R. Glover and R. Lum
Hsp104 is molecular chaperone in the AAA+ family of ATPases
that specializes in the resolubilization and refolding of
thermally denatured proteins in yeast. In addition to providing
high levels of thermotolerance, Hsp104 plays a pivotal role
in the propagation of yeast prions, self-replicating, amyloid-like
aggregates that are inherited during mitosis and meiosis.
In this review, the structure and function of Hsp104 is discussed,
its functional interaction with other molecular chaperones,
and a model for disaggregation and refolding is proposed.
[Back to top]
[Purchase
Article] [PMID:
19519517 PubMed - indexed for MEDLINE]
Hsp104 and Prion Propagation
N.V. Romanova and Y.O. Chernoff
High-ordered aggregates (amyloids) may disrupt cell functions,
cause toxicity at certain conditions and provide a basis for
self-perpetuated, protein-based infectious heritable agents
(prions). Heat shock proteins acting as molecular chaperones
counteract protein aggregation and influence amyloid propagation.
The yeast Hsp104/Hsp70/Hsp40 chaperone complex plays a crucial
role in interactions with both ordered and unordered aggregates.
The main focus of this review will be on the Hsp104 chaperone,
a molecular “disaggregase”.
[Back to top]
[Purchase
Article] [PMID:
19519518 PubMed - indexed for MEDLINE]
Heat Shock Protein 40: Structural Studies and Their
Functional Implications
J. Li, X. Qian and B. Sha
The mechanism by which Hsp40 and other molecular chaperones
recognize and interact with non-native polypeptides is a fundamental
question, as is how Hsp40 co-operates with Hsp70 to facilitate
protein folding. Years of structural studies of Hsp40 from
yeast and other species, conducted using X-ray protein crystallography,
NMR and small-angle X-ray scattering, have shed light on the
mechanisms how Hsp40 functions as a molecular chaperone and
how Hsp40-Hsp70 pair promotes protein folding, protein transport
and degradation. This review provides a discussion of recent
structural studies of Hsp40s and their functional implications.
[Back to top]
[Purchase
Article] [PMID:
19519519 PubMed - indexed for MEDLINE]
Essential Structural and Functional Features of Small
Heat Shock Proteins in Molecular Chaperoning Process
S. Kocabiyik
Small heat shock proteins are ubiquitously found in all
three domains of life, although they are the most poorly conserved
family of molecular chaperones. Their involvement in anti-stress
mechanisms of the cells have been clearly demonstrated by
induction of their expression in response to various environmental
and pathological stresses. Small heat shock proteins comprise
the most effective chaperone family concerning their unusual
capacity of substrate binding. It is well documented that
small heat shock proteins associate with unfolding substrate
proteins and form large oligomeric complexes to prevent their
aggregation and accumulation, that otherwise would impair
the normal cell functions. The substrates captured by small
heat shock proteins are further refolded to their native state
by ATP depended chaperones. During heat stress, the induced
expression and activation of the small heat shock proteins,
might reflect that this mechanism of protein quality control
contributes to acquired thermotolerance in hyperthermophilic
archaea, as well.
[Back to top]
[Purchase
Article] [PMID:
19519520 PubMed - indexed for MEDLINE]
Structural and Functional Diversity Among Eukaryotic
Hsp70 Nucleotide Exchange Factors
M. Kabani
Since their recent identification, eukaryotic Hsp70 nucleotide
exchange factors (NEFs) have gained increasing interest due
to their engagement in vital cellular processes. Here, I summarize
our current knowledge of their mechanisms of action, regulations
and cellular functions as well as their relevance for human
diseases such as cystic fibrosis or amyloidoses.
[Back to top]
[Purchase
Article] [PMID:
19519521 PubMed - indexed for MEDLINE]
Tethering Creates Unusual Kinetics for Ribosome-Associated
Chaperones with Nascent Chains
S.N. Witt
This article focuses on ribosome-associated chaperones.
A chaperone bound close to the exit tunnel on a ribosome 25
Å
from the emerging nascent chain has an effective concentration
of 1 x 10-1 M, which is 4-5
orders of magnitude larger than the concentration of the chaperone
in the cytosol. Ribosome-bound chaperones bind nascent chains
intramolecularly with rates as large as 104
s-1 in order to keep chains
unfolded.
[Back to top]
[Purchase
Article] [PMID:
19519522 PubMed - indexed for MEDLINE]
Application of GFP-Labeling to Study Prions in Yeast
L.E. Greene, Y.-N. Park, D.C. Masison and
E. Eisenberg
Fluorescent live cell imaging has recently been used
in numerous studies to examine prions in yeast. These fluorescence
studies take advantage of the fact that unlike the normally
folded form, the misfolded amyloid form of the prion protein
is aggregated. The studies have used fluorescence to identify
new prions, to study the transmission of prion from mother
to daughter, and to understand the role of molecular chaperones
in this transmission. The use of fluorescence imaging complements
the more standard methods used to study prion propagation.
This review discusses the various studies that have taken
advantage of fluorescence imaging technique particularly in
regard to understanding the transmission and curing of the
[PSI+], the prion
form of the translation termination factor Sup35p.
[Back to top]
[Purchase
Article] [PMID:
19519523 PubMed - indexed for MEDLINE]
A Unique Mechanism of Chaperone Action: Heme Regulation
of Hap1 Activity Involves Separate Control of Repression and
Activation
H.C. Lee and L. Zhang
The Hsp90 and Hsp70 molecular chaperones play important
roles in the folding and proper functioning of diverse cellular
proteins, including transcriptional regulators and protein
kinases. In yeast, several transcriptional regulators and
protein kinases are known to be substrates for Hsp90 and Hsp70
molecular chaperones. The yeast heme activator protein Hap1
promotes transcription of many genes in response to heme.
It requires Hsp90 and Hsp70 molecular chaperones for its activity
to be precisely regulated by heme concentration. The mechanism
by which molecular chaperones promote heme regulation of Hap1
activity is distinct from the mechanism by which molecular
chaperones promote steroid signaling. Hsp70 and Hsp90 molecular
chaperones act separately to promote Hap1 repression in heme-deficient
cells and heme activation of Hap1 in heme-sufficient cells.
Likewise, distinct Hap1 elements or domains act to mediate
Hap1 repression and heme activation separately. In this review,
we summarize the current knowledge about the molecular mechanism
governing heme regulation of Hap1 activity, and we compare
this mechanism to the molecular mechanism by which Hsp90 and
Hsp70 molecular chaperones promote the regulation of glucocorticoid
receptor, the most extensively studied substrate of Hsp90
and Hsp70 molecular chaperones.
[Back to top]
[Purchase
Article] [PMID:
19519524 PubMed - indexed for MEDLINE]
Reduced NGF Secretion by HT-29 Human Colon Cancer
Cells Treated with a GRPR Antagonist
C.B. de Farias, L. Stertz, R.C. Lima, F.
Kapczinski, G. Schwartsmann and R. Roesler
The gastrin-releasing peptide receptor (GRPR) is a therapeutic
target in colon cancer. Here we show that the GRPR antagonist
RC-3095 (10-3, 10-6,
or 1 μM)
decreases nerve growth factor (NGF) secretion measured by
enzyme-linked immunosorbent assay (ELISA) in HT-29 human colon
carcinoma cells. The results suggest that decreased secretion
of neurotrophins might be a novel mechanism by which GRPR
antagonists exert their antiproliferative effects in cancer
cells.
[Back to top]
[Purchase
Article] [PMID:
19519525 PubMed - indexed for MEDLINE]
Inhibitory Effects of β-Cyclodextrin
and Trehalose on Nanofibril and AGE Formation During Glycation
of Human Serum Albumin
E. Sharifi, N. Sattarahmady, M. Habibi-Rezaei,
M. Farhadi, N. Sheibani, F. Ahmad and A.A. Moosavi-Movahedi
The effects of β-cyclodextrin
(β-CyD)
and trehalose on glycation of human serum albumin (HSA) were
studied. These additives reduced AGEs and nanofibril formation
of HSA under in vitro glycation conditions and improved
its helical structure. These were accomplished through direct
interactions of them with HSA and alterations in solute-protein
interactions.
[Back to top]
[Purchase
Article] [PMID:
19519526 PubMed - indexed for MEDLINE]
Identification of a Molten Globule Like State in HC-N
Fragment of Botulinum Neurotoxin A: Shedding Light on the
Poorly Known Features of a Conserved Sub-Domain
L. Hasani, B. Ranjbar, M. Tavallaie and
M. Sadeghizadeh
C-terminal fragment of the Botulinum neurotoxin A comprises
two sub-domains including HC-N
and HC-C. Here, the conformational
change of HC-N was studied
by spectroscopic techniques. The results indicated that the
partially unfolded state forms during unfolding of HC-N.
This finding may shed light on poorly – known features
of the protein.
[Back to top]
[Purchase
Article] [PMID:
19519527 PubMed - indexed for MEDLINE]
Protein Engineering of a Fibroblast Growth Factor
2 Protein for Targeting to Bone Mineral Hydroxyapatite
E. Jeon and J.-H. Jang
The engineering of a novel FGF2 fused with highly conserved
bone mineral-binding domain of osteocalcin (OC) for targeting
to bone mineral hydroxyapatite (HA) exhibited much stronger
HA-binding affinity than native FGF2. FGF2-OC also showed
a significant increase of mitogenic activity and cellular
differentiation of osteoblastic cells compared with native
FGF2.
[Back to top]
[Purchase
Article] [PMID:
19519528 PubMed - indexed for MEDLINE]
Efficient Production of Human β-Defensin
2 (HBD2) in Escherichia coli
T. Vargues, G.J. Morrison, E.S. Seo, D.J.
Clarke, H.L. Fielder, J. Bennani, U. Pathania, F. Kilanowski,
J.R. Dorin, J.R.W. Govan, C.L. Mackay, D. Uhrín and
D.J. Campopiano
Human β-defensin
2 (HBD2) has been shown to interact with pathogenic bacteria
and components of the mammalian innate and adaptive immune
response. We describe a quick and reliable method for the
production of HBD2 in Escherichia coli. HBD2 was
expressed as an insoluble fusion, chemically cleaved and oxidised
to give a single, folded HBD2 β-isoform.
The purified peptide was analysed by high resolution mass
spectrometry, displayed a well-dispersed 1H
NMR spectrum, was a chemoattractant to HEK293 cells expressing
CCR6 and acted as an antimicrobial agent against E. coli,
P. aeruginosa, C. albicans and S. aureus.
[Back to top]
[Purchase
Article]
[PMID:
19519529 PubMed - indexed for MEDLINE]
Glycan-Binding Profile and Cell Adhesion Activity
of American Bullfrog (Rana catesbeiana) Oocyte Galectin-1
S.M.A. Kawsar, R. Matsumoto, Y. Fujii, H.
Yasumitsu, H. Uchiyama, M. Hosono, K. Nitta, J. Hamako, T.
Matsui, N. Kojima and Y. Ozeki
The glycan-binding profile of a β-galactoside-binding
15 kDa lectin (Galectin-1) purified from the oocytes of the
American bullfrog, Rana catesbeiana, was studied
using 61 pyridyl-aminated oligosaccharides by frontal affinity
chromatography. Human blood type-A-hexasaccharide (GalNAcα1-3(Fucα1-2)Galβ1-4GlcNAcβ1-4Galβ1
4Glc) was found to exhibit the strongest ligand binding to
the galectin while Forssman antigen (GalNAcα1-3GalNAcβ1-3Galα1-4Galβ1-4Glc)
and type-A-tetrasaccharide (GalNAcα1-3(Fucα1-2)Galβ1-4GlcNAcβ1-4Glc)
were also extensively recognized. The kinetics of affinity
of galectin-1 to type-A oligosaccharide was analysed by surface
plasmon resonance using neoglycoprotein with type-A oligosaccharides.
R. catesbeiana oocyte galectin adhered to human rhabdomyosarcoma
cells dose dependently and the activity was specifically cancelled
by the neoglycoprotein. It was concluded that galectin-1 from
R. catesbeiana oocytes possesses different and rare
glycan-binding properties from typical members in galectin
family.
[Back to top]
[Purchase
Article] [PMID:
19519530 PubMed - indexed for MEDLINE]
Proteome Analysis of Rice Root Plasma Membrane and
Detection of Cold Stress Responsive Proteins
M. Hashimoto, M. Toorchi, K. Matsushita,
Y. Iwasaki and S. Komatsu
To investigate the function of plant plasma membrane,
proteins of rice plasma membrane were analyzed and the proteins
changed by cold stress were identified. Plasma membrane proteins
were purified with an aqueous two-phase partitioning method
from root of rice seedlings, and activity of specific H+-ATPase
localized in plasma membranes was measured. The plasma membrane
proteins were separated by SDS-PAGE or 2D-PAGE, and analyzed
with nano LC-MS/MS. The number of transmembrane helices was
predicted from the amino acid sequence of annotated proteins.
Functional categorization revealed that the most of proteins
were associated with energy production, signal transduction,
protein synthesis, cell growth/division and defense. In addition,
12 cold stress responsive proteins were identified from the
plasma membrane using 2D-PAGE based proteomics method. Out
of them, cold shock protein-1 was significantly decreased
in plasma membrane of rice under cold stress.
[Back to top]
[Purchase
Article] [PMID:
19519531 PubMed - indexed for MEDLINE]
Exploring Rat Plasmatic Proteomes: What Triggered
the Liver Regeneration?
X.Y. Deng, W.R. Li, Y.W. Sun, H.D. Wei,
Y. Jiang and F.C. He
To further clarify the priming mechanism of liver regeneration,
proteins and protein complexes from rat plasma (normal group,
partial hepatectomy (PHx) group and sham-operation group)
were comparatively studied by two-dimensional gel electrophoresis
and two-dimensional blue native gel electrophoresis. Our results
suggested that Kupffer cell—NF-κB/ROS
might trigger the liver regeneration.
[Back to top]
[Purchase
Article] [PMID:
19519532 PubMed - indexed for MEDLINE]
New Approach to Achieve High-Level Secretory Expression
of Heterologous Proteins by Using Tat Signal Peptide
Y.-D. Li, Z. Zhou, L.-X. Lv, X.-P. Hou and
Y.-Q. Li
The twin-arginine translocation (Tat) pathway is an attractive
route for secretory production of heterologous proteins in
E. coli. In this study, we investigated the potential
use of Tat signal peptide from S. coelicolor to improve
secretory expression. The results showed that Tat signal peptide
(ssDagA) could effectively secrete active Green fluorescent
protein (GFP) to periplasm. When the rare codons of signal
sequence were optimized, the expression and secretion yield
of GFP improved by about 2-3 folds as detected qualitatively
by western blotting and fluorescent analysis. The increase
of translation rate could be explained by the unstability
of mRNA secondary structure. In summary, our strategy could
provide a new approach for high-level secretory expression
of heterologous proteins in E. coli.
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