共查询到20条相似文献,搜索用时 62 毫秒
1.
2.
3.
Molecular investigations during wheat germination have revealed unique developmentally regulated proteins, designated as germins, which show remarkable resistance to broad specificity proteases and to dissociation in SDS. Germins in cereals have an oxalate oxidase activity, which generates H2O2 from the oxidative breakdown of oxalate thereby playing a significant role in plant development and defense. Germin like proteins (GLPs) exhibit sequence and structural similarity with the cereal germins but mostly lack oxalate oxidase activity. Germins and germin like proteins (GLPs) are a class of developmentally regulated glycoproteins characterized by a beta-barrel core structure, a signal peptide, and are associated with the cell wall. GLPs exhibit a broad range of diversity in their occurrence and activity in organisms ranging from myxomycetes, bryophytes, pteridophytes, gymnosperms and angiosperms. Germins and GLPs are thought to play a significant role during zygotic and somatic embryogenesis (wheat and Pinus, respectively), salt stress (barley and Mesembryanthemum crystallinum), pathogen elicitation (wheat and barley), and heavy metal stress, etc. Characterization and cloning of some of the genes encoding germins and GLPs has facilitated a better understanding of their regulation and raised their potential of biotechnological application. 相似文献
4.
Increased Septoria musiva resistance in transgenic hybrid poplar leaves expressing a wheat oxalate oxidase gene 总被引:8,自引:0,他引:8
Liang Haiying Maynard Charles A. Allen Randy D. Powell William A. 《Plant molecular biology》2001,45(6):619-629
A cDNA clone of a wheat germin-like oxalate oxidase (OxO) gene regulated by the constitutive CaMV 35S promoter was expressed in a hybrid poplar clone, Populus × euramericana (`Ogy'). Previous studies showed that OxO is likely to play an important role in several aspects of plant development, stress response, and defense against pathogens. In order to study this wheat oxalate oxidase gene in woody plants, the expression of this gene and the functions of the encoded enzyme were examined in vitro and in vivo in transgenic `Ogy'. The enzyme activity in the transformed `Ogy' was visualized by histochemical assays and in SDS-polyacrylamide gels. It was found that the wheat OxO gene is expressed in leaves, stems, and roots of the transgenic `Ogy' plants and the encoded enzyme is able to break down oxalic acid. Transgenic `Ogy' leaves were more tolerant to oxalic acid as well as more effective in increasing the pH in an oxalic acid solution when compared to untransformed controls. In addition, when leaf disks from `Ogy' plants were inoculated with conidia of the poplar pathogenic fungus Septoria musiva, which produces oxalic acid, the OxO-transformed plants were more resistant than the untransformed controls. 相似文献
5.
Arabidopsis thaliana germin-like proteins: common and specific features point to a variety of functions 总被引:1,自引:0,他引:1
Germin-like proteins (GLPs) are ubiquitous plant proteins encoded by diverse multigene families. It is not known whether
they share germin's unusual biochemical properties and oxalate oxidase activity. Using specific antibodies, we have studied
three GLPs (AtGER1, AtGER2 and AtGER3) in Arabidopsis thaliana (L.) Heynh. as well as in transgenic tobacco (Nicotiana tabacum L.) plants overexpressing these proteins. Like wheat (Triticum aestivum L.) germin, these Arabidopsis GLPs are associated with the extracellular matrix (ECM) and they also seem to exist as two glycosylated isoforms. However,
none of them is an oxalate oxidase. Although GLPs display several conserved features, each has its specific characteristics.
Both AtGER2 and AtGER3 are oligomeric proteins that share germin's resistance to pepsin and to dissociation by heat and SDS.
In contrast, AtGER1 seems to exist as a monomer. The GLPs may interact with the ECM in a variety of ways, since each is efficiently
extracted by different conditions. In addition, germins and GLPs all bind Cibacron Blue, a dye often but not exclusively used
for the purification of enzymes having nucleotide cofactors. In the case of AtGER2, binding to the dye is so tight that it
almost allows a one-step purification of this protein. The variety of sequences, expression patterns and biochemical features
indicates that GLPs could be a class of receptors localized in the ECM and involved in physiological and developmental processes
as well as stress response.
Received: 28 June 1999 / Accepted: 6 December 1999 相似文献
6.
Garima Agarwal Malligarjunan Rajavel Balasubramanian Gopal Narayanaswamy Srinivasan 《PloS one》2009,4(5)
Background
The members of cupin superfamily exhibit large variations in their sequences, functions, organization of domains, quaternary associations and the nature of bound metal ion, despite having a conserved β-barrel structural scaffold. Here, an attempt has been made to understand structure-function relationships among the members of this diverse superfamily and identify the principles governing functional diversity. The cupin superfamily also contains proteins for which the structures are available through world-wide structural genomics initiatives but characterized as “hypothetical”. We have explored the feasibility of obtaining clues to functions of such proteins by means of comparative analysis with cupins of known structure and function.Methodology/Principal Findings
A 3-D structure-based phylogenetic approach was undertaken. Interestingly, a dendrogram generated solely on the basis of structural dissimilarity measure at the level of domain folds was found to cluster functionally similar members. This clustering also reflects an independent evolution of the two domains in bicupins. Close examination of structural superposition of members across various functional clusters reveals structural variations in regions that not only form the active site pocket but are also involved in interaction with another domain in the same polypeptide or in the oligomer.Conclusions/Significance
Structure-based phylogeny of cupins can influence identification of functions of proteins of yet unknown function with cupin fold. This approach can be extended to other proteins with a common fold that show high evolutionary divergence. This approach is expected to have an influence on the function annotation in structural genomics initiatives. 相似文献7.
8.
Martha H. Stipanuk Chad R. Simmons P. Andrew Karplus John E. DominyJr. 《Amino acids》2011,41(1):91-102
Proteins in the cupin superfamily have a wide range of biological functions in archaea, bacteria and eukaryotes. Although
proteins in the cupin superfamily show very low overall sequence similarity, they all contain two short but partially conserved
cupin sequence motifs separated by a less conserved intermotif region that varies both in length and amino acid sequence.
Furthermore, these proteins all share a common architecture described as a six-stranded β-barrel core, and this canonical
cupin or “jelly roll” β-barrel is formed with cupin motif 1, the intermotif region, and cupin motif 2 each forming two of
the core six β-strands in the folded protein structure. The recently obtained crystal structures of cysteine dioxygenase (CDO),
with contains conserved cupin motifs, show that it has the predicted canonical cupin β-barrel fold. Although there had been
no reports of CDO activity in prokaryotes, we identified a number of bacterial cupin proteins of unknown function that share
low similarity with mammalian CDO and that conserve many residues in the active-site pocket of CDO. Putative bacterial CDOs
predicted to have CDO activity were shown to have similar substrate specificity and kinetic parameters as eukaryotic CDOs.
Information gleaned from crystal structures of mammalian CDO along with sequence information for homologs shown to have CDO
activity facilitated the identification of a CDO family fingerprint motif. One key feature of the CDO fingerprint motif is
that the canonical metal-binding glutamate residue in cupin motif 1 is replaced by a cysteine (in mammalian CDOs) or by a
glycine (bacterial CDOs). The recent report that some putative bacterial CDO homologs are actually 3-mercaptopropionate dioxygenases
suggests that the CDO family may include proteins with specificities for other thiol substrates. A paralog of CDO in mammals
was also identified and shown to be the other mammalian thiol dioxygenase, cysteamine dioxygenase (ADO). A tentative fingerprint
motif for ADOs, or DUF1637 family members, is proposed. In ADOs, the conserved glutamate residue in cupin motif 1 is replaced
by either glycine or valine. Both ADOs and CDOs appear to represent unique clades within the cupin superfamily. 相似文献
9.
Jim M. Dunwell Alastair Culham Carol E. Carter Carlos R. Sosa-Aguirre Peter W. Goodenough 《Trends in biochemical sciences》2001,26(12):740-746
The cupin superfamily of proteins is among the most functionally diverse of any described to date. It was named on the basis of the conserved β-barrel fold (‘cupa’ is the Latin term for a small barrel), and comprises both enzymatic and non-enzymatic members, which have either one or two cupin domains. Within the conserved tertiary structure, the variety of biochemical function is provided by minor variation of the residues in the active site and the identity of the bound metal ion. This review discusses the advantages of this particular scaffold and provides an evolutionary analysis of 18 different subclasses within the cupin superfamily. 相似文献
10.
Cupins: the most functionally diverse protein superfamily? 总被引:10,自引:0,他引:10
11.
12.
Transient expression of members of the germin-like gene family in epidermal cells of wheat confers disease resistance 总被引:16,自引:0,他引:16
Schweizer P Christoffel A Dudler R 《The Plant journal : for cell and molecular biology》1999,20(5):541-552
The wheat genome encodes a family of germin-like proteins that differ with respect to regulation and tissue specificity of expression of the corresponding genes. While germin exhibits oxalate oxidase (E.C. 1.2.3.4.) activity, the germin-like proteins (GLPs) have no known enzymatic activity. A role of oxalate oxidase in plant defence has been proposed, based on the capacity of the enzyme to produce H2O2, a reactive oxygen species. The role in defence of germin and other members of the germin-like gene family was functionally assessed in a transient assay system based on particle bombardment of wheat leaves. Transient expression of the pathogen-induced germin gf-2.8 gene, but not of the constitutively expressed HvGLP1 gene, reduced the penetration efficiency of Blumeria (syn. Erysiphe) graminis f.sp. tritici, the causal agent of wheat powdery mildew, on transformed cells. Two engineered germin-gf-2.8 genes and the TaGLP2a gene, which all encoded proteins without oxalate oxidase activity, also reduced the penetration efficiency of the fungus, demonstrating that oxalate oxidase activity is not required for conferring enhanced resistance. Instead, activity tagging experiments showed that in cells transiently expressing the germin gf-2.8 gene, the transgene product became insolubilized at sites of attempted fungal penetration where localised production of H2O2 was observed. Thus, germin and GLPs may play a structural role in cell-wall re-enforcement during pathogen attack. 相似文献
13.
Zardoya R 《Biology of the cell / under the auspices of the European Cell Biology Organization》2005,97(6):397-414
BACKGROUND INFORMATION: MIPs (major intrinsic proteins) form channels across biological membranes that control recruitment of water and small solutes such as glycerol and urea in all living organisms. Because of their widespread occurrence and large number, MIPs are a sound model system to understand evolutionary mechanisms underlying the generation of protein structural and functional diversity. With the recent increase in genomic projects, there is a considerable increase in the quantity and taxonomic range of MIPs in molecular databases. RESULTS: In the present study, I compiled more than 450 non-redundant amino acid sequences of MIPs from NCBI databases. Phylogenetic analyses using Bayesian inference reconstructed a statistically robust tree that allowed the classification of members of the family into two main evolutionary groups, the GLPs (glycerol-uptake facilitators or aquaglyceroporins) and the water transport channels or AQPs (aquaporins). Separate phylogenetic analyses of each of the MIP subfamilies were performed to determine the main groups of orthology. In addition, comparative sequence analyses were conducted to identify conserved signatures in the MIP molecule. CONCLUSIONS: The earliest and major gene duplication event in the history of the MIP family led to its main functional split into GLPs and AQPs. GLPs show typically one single copy in microbes (eubacteria, archaea and fungi), up to four paralogues in vertebrates and they are absent from plants. AQPs are usually single in microbes and show their greatest numbers and diversity in angiosperms and vertebrates. Functional recruitment of NOD26-like intrinsic proteins to glycerol transport due to the absence of GLPs in plants was highly supported. Acquisition of other MIP functions such as permeability to ammonia, arsenite or CO2 is restricted to particular MIP paralogues. Up to eight fairly conserved boxes were inferred in the primary sequence of the MIP molecule. All of them mapped on to one side of the channel except the conserved glycine residues from helices 2 and 5 that were found in the opposite side. 相似文献
14.
Cotton (Gossypium hirsutum L.) contains a germin-like protein (GLP), GhGLP1, that shows tissue-specific accumulation in fiber. The fiber GLP is an oligomeric, glycosylated protein with a subunit size of approximately 25.5 kDa. Accumulation of GhGLP1 occurs during the period of fiber elongation [4–14 days post-anthesis (DPA)]. During early phases of fiber development (2–4 DPA), GhGLP1 localizes to cytoplasmic vesicles as shown by confocal immunofluorescent microscopy. In slightly older fibers (7–10 DPA), GhGLP1 localizes to the apoplast. In other plants, germins and GLPs have been reported to have enzymatic activities including oxalate oxidase (OxO), superoxide dismutase, and ADP-glucose pyrophosphatase. Cotton fiber extracts did not contain OxO activity, nor did intact fibers stain for OxO activity. A four-step purification protocol involving ammonium sulfate precipitation of a 1.0 M NaCl extract, ion-exchange chromatography on DEAE-Trisacryl M, lectin-affinity chromatography, and gel filtration chromatography resulted in electrophoretically pure GhGLP1. While 1.0 M NaCl extracts from 10–14 DPA fiber contained superoxide dismutase and phosphodiesterase activities, GhGLP1 could be separated from both enzyme activities by the purification protocol. Although a GLP accumulates in the cotton fiber apoplast during cell elongation, the function of this protein in fiber growth and development remains unknown.Abbreviations ABP
Auxin binding protein
- AGPPase
ADP-Glucose pyrophosphatase/phosphodiesterase
- bis-PNPP
Bis-p-nitrophenol phosphate
- ConA
Concanavalin A
- DOA
Day of anthesis
- DPA
Days post-anthesis
- GLP
Germin-like protein
- Mn-SOD
Manganese superoxide dismutase
- OxO
Oxalate oxidase
- PBS
Phosphate-buffered saline 相似文献
15.
16.
Simeon O. Kotchoni Jose C. Jimenez-Lopez Dongying Gao Vincent Edwards Emma W. Gachomo Venu M. Margam Manfredo J. Seufferheld 《PloS one》2010,5(7)
The completion of the rice genome sequence has made it possible to identify and characterize new genes and to perform comparative genomics studies across taxa. The aldehyde dehydrogenase (ALDH) gene superfamily encoding for NAD(P)+-dependent enzymes is found in all major plant and animal taxa. However, the characterization of plant ALDHs has lagged behind their animal- and prokaryotic-ALDH homologs. In plants, ALDHs are involved in abiotic stress tolerance, male sterility restoration, embryo development and seed viability and maturation. However, there is still no structural property-dependent functional characterization of ALDH protein superfamily in plants. In this paper, we identify members of the rice ALDH gene superfamily and use the evolutionary nesting events of retrotransposons and protein-modeling–based structural reconstitution to report the genetic and molecular and structural features of each member of the rice ALDH superfamily in abiotic/biotic stress responses and developmental processes. Our results indicate that rice-ALDHs are the most expanded plant ALDHs ever characterized. This work represents the first report of specific structural features mediating functionality of the whole families of ALDHs in an organism ever characterized. 相似文献
17.
Small GTP-binding Proteins and their Functions in Plants 总被引:2,自引:0,他引:2
Qing-Hu Ma 《Journal of Plant Growth Regulation》2007,26(4):369-388
Small GTP-binding proteins exist in eukaryotes from yeast to animals to plants and constitute a superfamily whose members
function as molecular switches that cycle between “active” and “inactive” states. They regulate a wide variety of cell functions
such as signal transduction, cell proliferation, cytoskeletal organization, intracellular membrane trafficking, and gene expression.
In yeast and animals, this superfamily is structurally classified into at least five families: the Ras, Rho, Rab, Arf/Sar1,
and Ran families. However, plants contain Rab, Rho, Arf, and Ran homologs, but no Ras. Small GTP-binding proteins have become
an intensively studied group of regulators not only in yeast and animals but also in plants in recent years. In this article
we briefly review the class and structure of small GTP-binding proteins. Their working modes and functions in animals and
yeast are listed, and the functions of individual members of these families in plants are discussed, with the emphasis on
the recently revealed plant-specific roles of these proteins, including their cross-talk with plant hormones and other signals,
regulation of organogenesis (leaf, root, and embryo), polar growth, cell division, and involvement in various stress and defense
responses. 相似文献
18.
Friends and relations of the cystatin superfamily--new members and their evolution. 总被引:6,自引:0,他引:6
下载免费PDF全文
![点击此处可从《Protein science : a publication of the Protein Society》网站下载免费的PDF全文](/ch/ext_images/free.gif)
W. M. Brown K. M. Dziegielewska 《Protein science : a publication of the Protein Society》1997,6(1):5-12
The cystatin "superfamily" encompasses proteins that contain multiple cystatin-like sequences. Some of the members are active cysteine protease inhibitors, while others have lost or perhaps never acquired this inhibitory activity. In recent years, several new members of the superfamily have characterized, including proteins from insects and plants. Based on partial amino acid homology, new members, such as the invariant chain (Ii), and the transforming growth factor-beta receptor type II (TGF-beta receptor II) may, in fact, represent members of an emerging family within the superfamily that may have used some common building blocks to form functionally diverse proteins. Cystatin super-family members have been found throughout evolution and members of each family of the superfamily are present in mammals today. In this review, the new and older, established members of the family are arranged into a possible evolutionary order, based on sequence homology and functional similarities. 相似文献
19.
Germin-like genes are expressed during somatic embryogenesis and early development of conifers 总被引:3,自引:0,他引:3
Mathieu M Lelu-Walter MA Blervacq AS David H Hawkins S Neutelings G 《Plant molecular biology》2006,61(4-5):615-627
Germins and germin-like proteins (GLPs) are members of a superfamily of proteins widely distributed in plants. Their localization
within the extracellular matrix and in some cases their hydrogen peroxide-producing activity suggests that these proteins
are involved in cell wall metabolism during stress responses and developmental processes. Several very highly conserved conifer
GLPs have been identified in somatic embryo tissues. In order to gain more knowledge on their potential involvement in the
development of this particular tissue, we have characterized a new GLP gene, LmGER1 in hybrid larch. Anti-GLP immunserum and in-gel activity analyses suggested the presence of superoxide dismutase activity
in apoplastic proteins from larch somatic embryos. These results could indicate a possible role for LmGER1 in this physiological process. The expression of LmGER1 has been followed during the maturation of somatic embryos and in different organs of young plantlets by homologous transformation
with a promoter-gus construct. This promoter was activated in the root cap of young embryos and, later on, in the cotyledons and in the vascular
procambium and xylem. Furthermore, the importance of this gene in embryo development was evaluated by transforming embryonal
masses with a gene construct encoding a hairpin RNA leading to gene silencing. The potential role of LmGER1 in cross-linking
of cell wall components is discussed. 相似文献
20.
The fact that the psp54 gene codes for p16, a seed chromatin protein of Pisum sativum, has been described previously. In the present paper it is shown that p54, the p16 precursor, also exists as a free polypeptide in pea and that it also yields p38, a second polypeptide from the N-terminal region of p54, which is co-localized at a subcellular level with p16. By using antibodies against pea p16 and p38, it was found that these proteins are present in the members of the tribe Viciae examined. Sequence analysis and 3D modelling indicates that p54 proteins belong to the cupin superfamily, and that they are related to sucrose binding proteins and, to a lesser extent, to vicilin-type seed storage proteins. Nevertheless, several distinctive characteristics of psp54 expression have been found: (i) the gene is differentially induced by ABA and several stress situations, in accordance with the presence of putative separate ABA and stress responsive elements in its promoter; (ii) the proteins are present in pods and seed coats, tissues of maternal origin; and (iii) p54 mRNA accumulates in the dry seeds. In view of both the functional properties of p54-derived proteins and the features of the psp54 gene expression, it is concluded that p54 represents a novel class within the cupin superfamily. 相似文献