Talukdar Muhammad Waliullah

Rim15 and Sch9 kinases are involved in induction of autophagic degradation of ribosomes in budding yeast

Autophagic degradation of ribosomes is promoted by nutrient starvation and inactivation of target of rapamycin complex 1 (TORC1). Here we show that selective autophagic degradation of ribosomes (called ribophagy) after TORC1 inactivation requires the specific autophagy receptor Atg11. Rim15 protein kinase upregulated ribophagy, while it downregulated non-selective degradation of ribosomes.

ANTIMICROBIAL POTENCY SCREENING OF CLERODENDRUM INFORTUNATUM LINN.

Plants play a major role in all the traditional system of medicine. Plants contain the rich source of natural products like vitamins, minerals and other immunemodulators. Most of which have been used for human welfare specially to cure disease caused by pathogenic microorganisms. The present study was conducted to determine the antimicrobial activity of C. infortunatum (Verbenaceae) with two different solvents viz; ethanol and ethyl acetate against medically important pathogens such as six gram positive bacterial strains, nine gram negative bacterial strains and seven fungal strains. The in vitro screening for antimicrobial activity was carried out by using disc diffusion and micro broth dilution techniques. All the extracts showed significant inhibitory activity over the bacteria and fungus comparable to the standard drug tetracycline and fluconazole. The maximum diameter zone of inhibition was recorded to bacterial strains against B. megaterium and B. subtilis; S. typhi, S. shiga and K. pneumoniae and to fungi against A. niger, A. flavus and C. albicans. The MIC values of ethanol leaf extract were determined 64 μg/ml to B. megaterium, S. typhi and K. pneumoniae; 128 μg/ml to S. aureus, S.-β–haemolyticus and E. coli according to the serial dilution technique. Most of the extracts of root, leaf and stem of C. infortunatum are effective against both organisms; bacteria and fungi, especially leaf extract > root extract > stem extract. Thus, C. infortunatum appears to be an effective material for development of antimicrobial drugs.

Yvh1 protein phosphatase is required for pre-autophagosomal structure formation after TORC1 inactivation

The pre-autophagosomal structure (PAS) is a putative site for autophagosome formation in budding yeast. Upon nutrient depletion or rapamycin treatment, target of rapamycin complex 1 (TORC1) becomes inactive, inducing PAS formation and autophagy. Here, we show that Yvh1 phosphatase is critical for PAS formation, but not autophagy induction, after TORC1 inactivation.

Orchestrated Action of PP2A Antagonizes Atg13 Phosphorylation and Promotes Autophagy after the Inactivation of TORC1

Target of rapamycin complex 1 (TORC1) phosphorylates autophagy-related Atg13 and represses autophagy under nutrient-rich conditions. However, when TORC1 becomes inactive upon nutrient depletion or treatment with the TORC1 inhibitor rapamycin, Atg13 dephosphorylation occurs rapidly, and autophagy is induced. At present, the phosphatases involved in Atg13 dephosphorylation remain unknown. Here, we show that two protein phosphatase 2A (PP2A) phosphatases, PP2A-Cdc55 and PP2A-Rts1, which are activated by inactivation of TORC1, are required for sufficient Atg13 dephosphorylation and autophagy induction after TORC1 inactivation in budding yeast. After rapamycin treatment, dephosphorylation of Atg13, activation of Atg1 kinase, pre-autophagosomal structure (PAS) formation and autophagy induction are all impaired in PP2A-deleted cells. Conversely, overexpression of non-phosphorylatable Atg13 suppressed defects in autophagy in PP2A mutant. This study revealed that the orchestrated action of PP2A antagonizes Atg13 phosphorylation and promotes autophagy after the inactivation of TORC1.

Evaluation of antimicrobial study in in vitro application of Clerodendrum infortunatum Linn.

Objective To evaluate the antimicrobial potency of ethanol and chloroform extracts of root, leaf and stem of Clerodendrum infortunatum (Verbenaceae) and to explore a scientific data as this plant was randomly use in traditional medicine to cure common ailments such as intestinal disorder, diarrhea, tuberculosis and respiratory problems, etc.

Synergistic effects of chlorpyrifos with piperonyl butoxide (pbo) against the lesser mealworm, Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae)

Objective To investigate the co-toxicity and co-efficient activity of Chlorpyrifos (Dursban 20EC), an organophosphate and Piperonyl butoxide (PBO) against the lesser meal worm Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae) (A. diaperinus).

CLIP and cohibin separate rDNA from nucleolar proteins destined for degradation by nucleophagy

Nutrient starvation or inactivation of target of rapamycin complex 1 (TORC1) in budding yeast induces nucleophagy, a selective autophagy process that preferentially degrades nucleolar components. DNA, including ribosomal DNA (rDNA), is not degraded by nucleophagy, even though rDNA is embedded in the nucleolus. Here, we show that TORC1 inactivation promotes relocalization of nucleolar proteins and rDNA to different sites. Nucleolar proteins move to sites proximal to the nuclear–vacuolar junction (NVJ), where micronucleophagy (or piecemeal microautophagy of the nucleus) occurs, whereas rDNA dissociates from nucleolar proteins and moves to sites distal to NVJs. CLIP and cohibin, which tether rDNA to the inner nuclear membrane, were required for repositioning of nucleolar proteins and rDNA, as well as effective nucleophagic degradation of the nucleolar proteins. Furthermore, micronucleophagy itself was necessary for the repositioning of rDNA and nucleolar proteins. However, rDNA escaped from nucleophagic degradation in CLIP- or cohibin-deficient cells. This study reveals that rDNA–nucleolar protein separation is important for the nucleophagic degradation of nucleolar proteins.

In vitro Antimicrobial Study for Biological Evaluation of Clerodendrum infortunatum Linn

OBJECTIVE To explore a scientific idea, this study was examined for evaluation of antimicrobial potency using root, leaf and stem of ethyl acetate and chloroform extracts of C. infortunatum (Verbenaceae) due to randomly use in traditional medicine to cure common ailments such as intestinal disorder, diarrhea, tuberculosis and respiratory problems etc. METHODS The in vitro application was carried out by using disc diffusion, micro broth dilution and serial dilution techniques against clinically important life threatening organisms. RESULTS All the extracts showed significant inhibitory activity over the bacteria and fungus comparable to the standard drug tetracycline and fluconazole. The maximum average diameter zone of inhibition was recorded to bacterial strains against B. megaterium, S. typhi, K. pneumoniae and to fungi against A. niger and C. albicans. The MIC values of ethyl acetate and chloroform root extract were determined 64 µg/ml to B. subtilis, and K. pneumoniae; to S.-β-haemolyticus and S. typhi for ethyl acetate extracts, 128 µg/ml to S. aureus, and E. coli for both ethyl acetate and chloroform root extracts but only S. typhi and S.-β-haemolyticus for chloroform extract. CONCLUSION The findings evidently appear promising antibacterial and antifungal properties of C. infortunatum against antagonistic pathogens. Leaf possess quite potent activity than root and stem specially root extract > leaf extract > stem extract. One of the more significant achievements of this study to follows and covers the most recent and important patents WO2009075290 (2009) which deals on yeast having immunopotentiating effect and food or feed. This study serves as basis for further research to lead compounds to be isolated so that may be as a template for the implications of these results for bioactivity and drug discovery potential of herbal products are discussed.

Cdc14 Phosphatase Promotes TORC1-Regulated Autophagy in Yeast

Cdc14 protein phosphatase is critical for late mitosis progression in budding yeast, although its orthologs in other organisms, including mammalian cells, function as stress-responsive phosphatases. We found herein unexpected roles of Cdc14 in autophagy induction after nutrient starvation and target of rapamycin complex 1 (TORC1) kinase inactivation. TORC1 kinase phosphorylates Atg13 to repress autophagy under nutrient-rich conditions, but if TORC1 becomes inactive upon nutrient starvation or rapamycin treatment, Atg13 is rapidly dephosphorylated and autophagy is induced. Cdc14 phosphatase was required for optimal Atg13 dephosphorylation, pre-autophagosomal structure formation, and autophagy induction after TORC1 inactivation. In addition, Cdc14 was required for sufficient induction of ATG8 and ATG13 expression. Moreover, Cdc14 activation provoked autophagy even under normal conditions. This study identified a novel role of Cdc14 as the stress-responsive phosphatase for autophagy induction in budding yeast.

Valuation of toxicity assay of crude drug; Clerodendrum infortunatum L

M expansion, which is used to correct transverse discrepancies between the maxilla and mandible, occurs through a combination of skeletal and dental expansion. Skeletal expansion involves separating the maxilla at the midpalatal suture. Sutural expansion is accomplished by stretching the collagenous fibres, which is then accompanied by new bone formation. After expansion, the suture undergoes remodelling by way of bone formation. However, although long-term retention is used to prevent relapse, there is generally a reduction of the width of the expanded maxillary arch. Clinically, bone begins to repair itself within weeks following expansion and lasts for months. Bone remodeling is dynamically equilibrated by bone-forming osteoblasts and bone-resorbing osteoclasts for several months up to 1 year. Free radicals function as intermediates in osteoclast activation, which is vital for bone resorption. Some studies showed that antioxidants affect bone metabolism, via an increase of osteoblastic activity. Recently, some studies have demonstrated that traditional medicines have beneficial therapeutic effects on accelerating new bone formation.\r\nThe current review focuses on pharmacological, clinical, and animal studies with chemically profiled extracts of some selected traditional medicinal plants (Salvia officinalis, S. miltiorrhizae, Ginkgo biloba, Hypericum perforatum, Nigella sativa etc.) in accelerating new bone formation, conducted by research groups in Turkey and abroad.I of apoptosis in human colon cancer cells by isorhamnetin glycosides from Opuntia ficus-indica: The aim of this investigation was to study how different glycosilation patterns of isorhamnetin derived from Opuntia ficus-indica affect their potential as a natural chemotherapeutic compounds. Isorhamnetin glycosideswere isolated by semi-preparative chromatography and identified with LC/MSD TOF and were chosen by their abundance in O. ficus-indica. It has already been reported that the isorhamnetin aglycone induced caspase dependent apoptosis on cancerous lung cells. On the other hand, it has been established that biological activities of flavonoids differ between aglycones and glycosides, and that monosaccharides type, number and position also exert an important effect. Therefore, in this study we tested four isorhamnetin glycosides to validate the apoptotic effect on colon cancer cellsusing annexin V and propidium iodide staining for flow cytometry. Significant differences between glycosides were evidentin a dose-dependent manner and the greatest induction of apoptosis was observed for isorhamnetin-3-O-glucosylpentosideat 100 μg/mL. Afterwards, mitochondrial membrane potential and reactive oxygen species (ROS)were determined via tetramethylrhodamine ethyl ester (TMRE) and 2,7-dichlorofluorescin diacetate (DCFDA), respectively. It was found that the highest membrane potential loss was generated by the same isorhamnetin glycoside with the strongest apoptotic effect while isorhamnetin3-O-glucosyl-rhamnsoyl-rhamnoside and isorhamnetin showed the lowest. In contrast with this, the highest ROS concentration was obtained with isorhamnetin. Results demonstrated that differences in the profile of sugars moieties of isorhmanetin affected apoptosis induction.