Identification of the family of aquaporin genes and their expression in upland cotton (<Emphasis Type="Italic">Gossypium hirsutum</Emphasis>L.)

Background  

Cotton (Gossypium spp.) is produced in over 30 countries and represents the most important natural fiber in the world. One of the primary factors affecting both the quantity and quality of cotton production is water. A major facilitator of water movement through cell membranes of cotton and other plants are the aquaporin proteins. Aquaporin proteins are present as diverse forms in plants, where they function as transport systems for water and other small molecules. The plant aquaporins belong to the large major intrinsic protein (MIP) family. In higher plants, they consist of five subfamilies including plasma membrane intrinsic proteins (PIP), tonoplast intrinsic proteins (TIP), NOD26-like intrinsic proteins (NIP), small basic intrinsic proteins (SIP), and the recently discovered X intrinsic proteins (XIP). Although a great deal is known about aquaporins in plants, very little is known in cotton.     

DNA barcoding of the <Emphasis Type="Italic">Lemnaceae</Emphasis>, a family of aquatic monocots

Background  

Members of the aquatic monocot family Lemnaceae (commonly called duckweeds) represent the smallest and fastest growing flowering plants. Their highly reduced morphology and infrequent flowering result in a dearth of characters for distinguishing between the nearly 38 species that exhibit these tiny, closely-related and often morphologically similar features within the same family of plants.     

Functional characterization of a small heat shock protein from <Emphasis Type="Italic">Mycobacterium leprae</Emphasis>

Background  

Small heat shock proteins are ubiquitous family of stress proteins, having a role in virulence and survival of the pathogen. M. leprae, the causative agent of leprosy is an uncultivable organism in defined media, hence the biology and function of proteins were examined by cloning M. leprae genes in heterologous hosts. The study on sHsp18 was carried out as the knowledge about the functions of this major immunodominant antigen of M. leprae is scanty.     

A single hydrophobic cleft in the <Emphasis Type="Italic">Escherichia coli</Emphasis> processivity clamp is sufficient to support cell viability and DNA damage-induced mutagenesis <Emphasis Type="Italic">in vivo</Emphasis>

Background  

The ubiquitous family of DnaN sliding processivity clamp proteins plays essential roles in DNA replication, DNA repair, and cell cycle progression, in part by managing the actions of the different proteins involved in these processes. Interactions of the homodimeric Escherichia coli β clamp with its known partners involves multiple surfaces, including a hydrophobic cleft located near the C-terminus of each clamp protomer.     

Contribution of SecDF to <Emphasis Type="Italic">Staphylococcus aureus</Emphasis>resistance and expression of virulence factors

Background  

SecDF is an accessory factor of the conserved Sec protein translocation machinery and belongs to the resistance-nodulation-cell division (RND) family of multidrug exporters. SecDF has been shown in Escherichia coli and Bacillus subtilis to be involved in the export of proteins. RND proteins can mediate resistance against various substances and might be of relevance in antimicrobial therapy. The role of RND proteins in Staphylococcus aureus has not yet been determined.     

Role of PII proteins in nitrogen fixation control of Herbaspirillum seropedicae strain SmR1

Background  

The PII protein family comprises homotrimeric proteins which act as transducers of the cellular nitrogen and carbon status in prokaryotes and plants. In Herbaspirillum seropedicae, two PII-like proteins (GlnB and GlnK), encoded by the genes glnB and glnK, were identified. The glnB gene is monocistronic and its expression is constitutive, while glnK is located in the nlmAglnKamtB operon and is expressed under nitrogen-limiting conditions.     

Structure and evolution of the plant cation diffusion facilitator family of ion transporters

Background  

Members of the cation diffusion facilitator (CDF) family are integral membrane divalent cation transporters that transport metal ions out of the cytoplasm either into the extracellular space or into internal compartments such as the vacuole. The spectrum of cations known to be transported by proteins of the CDF family include Zn, Fe, Co, Cd, and Mn. Members of this family have been identified in prokaryotes, eukaryotes, and archaea, and in sequenced plant genomes. CDF families range in size from nine members in Selaginella moellendorffii to 19 members in Populus trichocarpa. Phylogenetic analysis suggests that the CDF family has expanded within plants, but a definitive plant CDF family phylogeny has not been constructed.     

Zebrafish RNase T2 genes and the evolution of secretory ribonucleases in animals

Background  

Members of the Ribonuclease (RNase) T2 family are common models for enzymological studies, and their evolution has been well characterized in plants. This family of acidic RNases is widespread, with members in almost all organisms including plants, animals, fungi, bacteria and even some viruses. While several biological functions have been proposed for these enzymes in plants, their role in animals is unknown. Interestingly, in vertebrates most of the biological roles of plant RNase T2 proteins are carried out by members of a different family, RNase A. Still, RNase T2 proteins are conserved in these animals     

A phylogenetic study of cytochrome <Emphasis Type="Italic">b</Emphasis>561 proteins

Background  

As an antioxidant and cofactor to numerous metabolic enzymes, ascorbate has an essential role in plants and animals. Cytochromes b561 constitute a class of intrinsic membrane proteins involved in ascorbate regeneration. Despite their importance in ascorbate metabolism, no evolutionary analysis has been presented so far on this newly described protein family.     

Relationships of gag-pol diversity between <Emphasis Type="Italic">Ty3/Gypsy</Emphasis> and <Emphasis Type="Italic">Retroviridae</Emphasis>LTR retroelements and the three kings hypothesis

Background  

The origin of vertebrate retroviruses (Retroviridae) is yet to be thoroughly investigated, but due to their similarity and identical gag-pol (and env) genome structure, it is accepted that they evolve from Ty3/Gypsy LTR retroelements the retrotransposons and retroviruses of plants, fungi and animals. These 2 groups of LTR retroelements code for 3 proteins rarely studied due to the high variability – gag polyprotein, protease and GPY/F module. In relation to 3 previously proposed Retroviridae classes I, II and II, investigation of the above proteins conclusively uncovers important insights regarding the ancient history of Ty3/Gypsy and Retroviridae LTR retroelements.     

Unique features of the rice blast resistance <Emphasis Type="Italic">Pish</Emphasis> locus revealed by large scale retrotransposon-tagging

Background  

R gene-mediated resistance is one of the most effective mechanisms of immunity against pathogens in plants. To date some components that regulate the primary steps of plant immunity have been isolated, however, the molecular dissection of defense signaling downstream of the R proteins remains to be completed. In addition, R genes are known to be highly variable, however, the molecular mechanisms responsible for this variability remain obscure.     

A family of GFP-like proteins with different spectral properties in lancelet <Emphasis Type="Italic">Branchiostoma floridae</Emphasis>

Background  

Members of the green fluorescent protein (GFP) family share sequence similarity and the 11-stranded β-barrel fold. Fluorescence or bright coloration, observed in many members of this family, is enabled by the intrinsic properties of the polypeptide chain itself, without the requirement for cofactors. Amino acid sequence of fluorescent proteins can be altered by genetic engineering to produce variants with different spectral properties, suitable for direct visualization of molecular and cellular processes. Naturally occurring GFP-like proteins include fluorescent proteins from cnidarians of the Hydrozoa and Anthozoa classes, and from copepods of the Pontellidae family, as well as non-fluorescent proteins from Anthozoa. Recently, an mRNA encoding a fluorescent GFP-like protein AmphiGFP, related to GFP from Pontellidae, has been isolated from the lancelet Branchiostoma floridae, a cephalochordate (Deheyn et al., Biol Bull, 2007 213:95).     

Genetic characterization of <Emphasis Type="Italic">psp</Emphasis> encoding the DING protein in <Emphasis Type="Italic">Pseudomonas fluorescens</Emphasis> SBW25

Background  

DING proteins constitute a conserved and broadly distributed set of proteins found in bacteria, fungi, plants and animals (including humans). Characterization of DING proteins from animal and plant tissues indicated ligand-binding ability suggesting a role for DING proteins in cell signaling and biomineralization. Surprisingly, the genes encoding DING proteins in eukaryotes have not been identified in the eukaryotic genome or EST databases. Recent discovery of a DING homologue (named Psp here) in the genome of Pseudomonas fluorescens SBW25 provided a unique opportunity to investigate the physiological roles of DING proteins. P. fluorescens SBW25 is a model bacterium that can efficiently colonize plant surfaces and enhance plant health. In this report we genetically characterize Psp with a focus on conditions under which psp is expressed and the protein exported.     

WD-repeat instability and diversification of the <Emphasis Type="Italic">Podospora anserina hnwd</Emphasis> non-self recognition gene family

Background  

Genes involved in non-self recognition and host defence are typically capable of rapid diversification and exploit specialized genetic mechanism to that end. Fungi display a non-self recognition phenomenon termed heterokaryon incompatibility that operates when cells of unlike genotype fuse and leads to the cell death of the fusion cell. In the fungus Podospora anserina, three genes controlling this allorecognition process het-d, het-e and het-r are paralogs belonging to the same hnwd gene family. HNWD proteins are STAND proteins (signal transduction NTPase with multiple domains) that display a WD-repeat domain controlling recognition specificity. Based on genomic sequence analysis of different P. anserina isolates, it was established that repeat regions of all members of the gene family are extremely polymorphic and undergoing concerted evolution arguing for frequent recombination within and between family members.     

The expression,processing and localization of polymorphic membrane proteins in <Emphasis Type="Italic">Chlamydia pneumoniae</Emphasis> strain CWL029

Background  

Chlamydiae are obligate intracellular bacteria, which are important human pathogens. Genome sequences of C. trachomatis and C. pneumoniae have revealed the presence of a Chlamydia specific gene family encoding polymorphic outer membrane proteins, Pmps. In C. pneumoniae the family comprises twenty-one members, which are all transcribed. In the present study, the expression, processing and localisation of the sixteen full-length Pmps in C. pneumoniae strain CWL029 have been further investigated by two-dimensional gel electrophoresis and immunofluorescence microscopy.     

A new picture of cell wall protein dynamics in elongating cells of <Emphasis Type="Italic">Arabidopsis thaliana</Emphasis>: Confirmed actors and newcomers

Background  

Cell elongation in plants requires addition and re-arrangements of cell wall components. Even if some protein families have been shown to play roles in these events, a global picture of proteins present in cell walls of elongating cells is still missing. A proteomic study was performed on etiolated hypocotyls of Arabidopsis used as model of cells undergoing elongation followed by growth arrest within a short time.     

Interaction of the heterotrimeric G protein alpha subunit SSG-1 of <Emphasis Type="Italic">Sporothrix schenckii</Emphasis> with proteins related to stress response and fungal pathogenicity using a yeast two-hybrid assay

Background  

Important biological processes require selective and orderly protein-protein interactions at every level of the signalling cascades. G proteins are a family of heterotrimeric GTPases that effect eukaryotic signal transduction through the coupling of cell surface receptors to cytoplasmic effector proteins. They have been associated with growth and pathogenicity in many fungi through gene knock-out studies. In Sporothrix schenckii, a pathogenic, dimorphic fungus, we previously identified a pertussis sensitive G alpha subunit, SSG-1. In this work we inquire into its interactions with other proteins.