Tebuconazole and trifloxystrobin regulate the physiology,antioxidant defense and methylglyoxal detoxification systems in conferring salt stress tolerance in Triticum aestivum L.

Physiology and Molecular Biology of Plants - Fungicides are widely used for controlling fungi in crop plants. However, their roles in conferring abiotic stress tolerance are still elusive. In this...     

Enzyme dimension of the ribosomal protein S4 across plant and animal kingdoms

Background

The protein S4 of the smaller ribosomal subunit is centrally important for its anchorage role in ribosome assembly and rRNA binding. Eubacterial S4 also facilitates synthesis of rRNA, and restrains translation of ribosomal proteins of the same polycistronic mRNA. Eukaryotic S4 has no homolog in eubacterial kingdom, nor are such extraribosomal functions of S4 known in plants and animals even as genetic evidence suggests that deficiency of S4X isoform in 46,XX human females may produce Turner syndrome (45,XO).

Methods

Recombinant human S4X and rice S4 were used to determine their enzymatic action in the cleavage of synthetic peptide substrates and natural proteins. We also studied autoproteolysis of the recombinant S4 proteins, and examined the growth and proliferation of S4-transfected human embryonic kidney cells.

Results

Extraribosomal enzyme nature of eukaryotic S4 is described. Both human S4X and rice S4 are cysteine proteases capable of hydrolyzing a wide spectrum of peptides and natural proteins of diverse origin. Whereas rice S4 also cleaves the -XXXD↓- consensus sequence assumed to be specific for caspase-9 and granzyme B, human S4 does not. Curiously, both human and rice S4 show multiple-site autoproteolysis leading to self-annihilation. Overexpression of human S4 blocks the growth and proliferation of transfected embryonic kidney cells, presumably due to the extraribosomal enzyme trait reported.

Conclusions

The S4 proteins of humans and rice, prototypes of eukaryota, are non-specific cysteine proteases in the extraribosomal milieu.

General significance

The enzyme nature of S4 is relevant toward understanding not only the origin of ribosomal proteins, but also processes in cell biology and diseases.     

Vapor of Volatile Oils from Litsea cubeba Seed Induces Apoptosis and Causes Cell Cycle Arrest in Lung Cancer Cells

Non-small cell lung carcinoma (NSCLC) is a major killer in cancer related human death. Its therapeutic intervention requires superior efficient molecule(s) as it often becomes resistant to present chemotherapy options. Here we report that vapor of volatile oil compounds obtained from Litsea cubeba seeds killed human NSCLC cells, A549, through the induction of apoptosis and cell cycle arrest. Vapor generated from the combined oils (VCO) deactivated Akt, a key player in cancer cell survival and proliferation. Interestingly VCO dephosphorylated Akt at both Ser⁴⁷³ and Thr³⁰⁸; through the suppression of mTOR and pPDK1 respectively. As a consequence of this, diminished phosphorylation of Bad occurred along with the decreased Bcl-xL expression. This subsequently enhanced Bax levels permitting the release of mitochondrial cytochrome c into the cytosol which concomitantly activated caspase 9 and caspase 3 resulting apoptotic cell death. Impairment of Akt activation by VCO also deactivated Mdm2 that effected overexpression of p53 which in turn upregulated p21 expression. This causes enhanced p21 binding to cyclin D1 that halted G1 to S phase progression. Taken together, VCO produces two prong effects on lung cancer cells, it induces apoptosis and blocked cancer cell proliferation, both occurred due to the deactivation of Akt. In addition, it has another crucial advantage: VCO could be directly delivered to lung cancer tissue through inhalation.     

Cloning, Escherichia coli expression, purification, characterization, and enzyme assay of the ribosomal protein S4 from wheat seedlings (Triticum vulgare)

S4 is a paradigm of ribosomal proteins involved in multifarious activities both within and outside the ribosome. For a detailed biochemical and structural investigations of eukaryotic S4, the wheat S4 gene has been cloned and expressed in Escherichia coli, and the protein purified to a high degree of homogeneity. The 285-residue recombinant protein containing an N-terminal His(6) tag along with fourteen additional residues derived from the cloning vector is characterized by a molecular mass of 31981.24 Da. The actual sequence of 265 amino acids having a molecular mass of 29931 Da completely defines the primary structure of wheat S4. Homology modeling shows a bi-lobed protein topology arising from folding of the polypeptide into two domains, consistent with the fold topology of prokaryotic S4. The purified protein is stable and folded since it can be reversibly unfolded in guanidinium hydrochloride, and is capable of hydrolyzing cysteine protease-specific peptide-based fluorescence substrates, including Ac-DEVD-AFC (N-acetyl-Asp-Glu-Val-Asp-7-amino-4-trifluoromethylcoumarin) and Z-FR-AMC (N-CBZ-Phe-Arg-aminomethylcoumarin).     

Structural Changes in the Relationships of Body Dimensions of Four Species of Pulmonate Slugs (Mollusca : Gastropoda : Pulmonata)

Four species of pulmonate slugs viz. Milax rusticus, Milax sowerbyi, Milax gagates and Limax tenellus are colonised along the north eastern region of Libya. These slugs are homogeneous in character since they belong to the same class and order. However, their body dimensions were significantly different. Significant positive relationships existed on most of the body dimensions of each species and these relationships were found to be heterogeneous among the four species studied.     

Tolerability and efficacy of single dose albendazole,diethylcarbamazine citrate (DEC) or co-administration of albendazole with DEC in the clearance of <Emphasis Type="Italic">Wuchereria bancrofti</Emphasis>in asymptomatic microfilaraemic volunteers in Pondicherry,South India: a hospital-based study

Background  

The tolerability and efficacy of single dose albendazole (400 mg), diethylcarbamazine citrate (DEC) (6 mg/kg bodyweight) or co-administration of albendazole (400 mg) + DEC (6 mg/kg bodyweight) was studied in 54 asymptomatic Wuchereria bancrofti microfilaraemic volunteers in a double blind hospital-based clinical study.