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"Keshava"
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Protein kinase TgCDPK7 regulates vesicular trafficking and phospholipid synthesis in Toxoplasma gondii
by
Katris, Nicholas J.
,
Prasad, T. S. Keshava
,
Antil, Neelam
in
Biochemistry, Molecular Biology
,
Biology and Life Sciences
,
Biosynthesis
2021
Apicomplexan parasites are causative agents of major human diseases. Calcium Dependent Protein Kinases (CDPKs) are crucial components for the intracellular development of apicomplexan parasites and are thus considered attractive drug targets. CDPK7 is an atypical member of this family, which initial characterization suggested to be critical for intracellular development of both Apicomplexa Plasmodium falciparum and Toxoplasma gondii . However, the mechanisms via which it regulates parasite replication have remained unknown. We performed quantitative phosphoproteomics of T . gondii lacking TgCDPK7 to identify its parasitic targets. Our analysis lead to the identification of several putative TgCDPK7 substrates implicated in critical processes like phospholipid (PL) synthesis and vesicular trafficking. Strikingly, phosphorylation of TgRab11a via TgCDPK7 was critical for parasite intracellular development and protein trafficking. Lipidomic analysis combined with biochemical and cellular studies confirmed that TgCDPK7 regulates phosphatidylethanolamine (PE) levels in T . gondii . These studies provide novel insights into the regulation of these processes that are critical for parasite development by TgCDPK7.
Journal Article
Depression in patients with chronic otolaryngology symptoms – A vicious cycle
by
Shenoy, Vijendra
,
K., Keshava Pai
,
Dosemane, Deviprasad
in
Age groups
,
Care and treatment
,
Chronic illnesses
2024
Background
Depression is a common comorbidity among individuals with otolaryngologic disorders, particularly those with longstanding conditions. This study aims at analysing the sociodemographic profile of depressive disorders in patients with chronic otolaryngology symptoms or conditions, and the correlation with PHQ-9 score.
Methods
A cross-sectional study was conducted on a hundred patients presenting to the outpatient department with chronic otolaryngology symptoms or conditions. They were requested to fill in the PHQ-9 questionnaire, containing questions based on the fourth edition of the
Diagnostic and Statistical Manual of Mental Disorders
(
DSM-IV
) for major depressive disorder (MDD).
Results
Median age was 39, male: female ratio was 1.17. Nasal obstruction (29%), ear discharge (25%), and headache (17%) were the common presenting complaints. Mean and median PHQ-9 scores were 5.03 and 4 respectively. Seven patients (7%) had MDD, while eleven (11%) had other depressive disorder; 9% of cases were found to have no significant otolaryngologic problem despite presenting with symptoms, two of which were found to have depressive disorder. Thirty-five (35%) and thirty-six (36%) patients had minimal and mild depressive symptoms respectively, while one (1%) had severe depressive symptoms. Statistical significance was noted for the duration of symptoms (p-value 0.005); high statistical significance was found for occupation and otolaryngology diagnosis (p-value < 0.001 each). PHQ-9 score showed statistical significance in comparison with gender and duration of symptoms (p-value 0.046 and 0.005 respectively). Correlation of severity of depressive disorder revealed statistical significance with gender (p-value 0.049) and high statistical significance with duration of symptoms (p-value < 0.001).
Conclusion
Chronic otolaryngology conditions are associated with significant morbidity, attributable to longstanding disturbing symptoms and prolonged treatment protocols, leading to depression. Nevertheless, depression in chronic otolaryngology disorders may aggravate or overlap the clinical symptoms or may go undetected. Hence it may be worthwhile to evaluate for depressive disorders in chronic patients presenting to otolaryngology.
Journal Article
Mechanical characterization & regression analysis of Calamus rotang based hybrid natural fibre composite with findings reported on retrieval bending strength
by
Sharanya, I. S.
,
Channa Keshava Reddy, K. L.
,
Nikam, Hrithika
in
639/166/988
,
639/301/1023
,
639/301/54
2024
Research on Bio-based natural fiber material promoted the development of reinforcement and expand their possible structural applications. In this study, fibers are extracted from the stem of
Calamus rotang
(common rattan-Indian Species). Further, the fiber is processed to get novel hybrid combinations with glass fibers by manual hand lay-up technique. Three sets of samples were prepared for the different volume fractions of 60:40, 30:30:30, and 60:32:8 of glass fiber/epoxy as neat composite sample (NCS), a hybrid combination of
C. rotang
/glass fiber with epoxy as modified reinforced composite sample (MRCS) and glass fiber/epoxy with calamus stem powder as modified matrix composite sample (MMCS) respectively. Mechanical tests including tensile, flexural, impact, and ILSS tests are conducted as per ASTM Standards. Comparative studies have been done to evaluate the effect of novel species of
C. rotang
on mechanical properties with neat GFRP composites. Addition to this regression analysis has been carried out to achieve the experimental correlation for tensile and bending tests. Microstructural analysis for all the tested samples has been done to assess the fracture mode. Novel findings on retrieval bending strength for MMCS has been reported for the first time for composite materials. Study proves that novel species have a significant impact on the basic properties of materials.
Journal Article
Protein kinase PfPK2 mediated signalling is critical for host erythrocyte invasion by malaria parasite
by
Rawat, Akanksha
,
Gupta, Ankit
,
Prasad, T. S. Keshava
in
Analysis
,
Animals
,
Apical membrane antigen 1
2023
Signalling pathways in malaria parasite remain poorly defined and major reason for this is the lack of understanding of the function of majority of parasite protein kinases and phosphatases in parasite signalling and its biology. In the present study, we have elucidated the function of Protein Kinase 2 (PfPK2), which is known to be indispensable for the survival of human malaria parasite Plasmodium falciparum . We demonstrate that it is involved in the invasion of host erythrocytes, which is critical for establishing infection. In addition, PfPK2 may also be involved in the maturation of the parasite post-invasion. PfPK2 regulates the release of microneme proteins like Apical Membrane Antigen 1 (AMA1), which facilitates the formation of Tight Junction between the merozoite and host erythrocyte- a key step in the process of invasion. Comparative phosphoproteomics studies revealed that PfPK2 may be involved in regulation of several key proteins involved in invasion and signalling. Furthermore, PfPK2 regulates the generation of cGMP and the release of calcium in the parasite, which are key second messengers for the process of invasion. These and other studies have shed light on a novel signalling pathway in which PfPK2 acts as an upstream regulator of important cGMP-calcium signalling, which plays an important role in parasite invasion.
Journal Article
Differences in milk metabolites in Malnad Gidda (Bos indicus) cows reared under pasture-based feeding system
2021
The milk and milk products from cows reared under grazing system are believed to be healthier and hence have high demand compared to milk from cows reared in the non-grazing system. However, the effect of grazing on milk metabolites, specifically lipids has not been fully understood. In this study, we used acetonitrile precipitation and methanol:chloroform methods for extracting the milk metabolites followed by liquid chromatography–tandem mass spectrometry (LC–MS/MS) run to identify the different metabolites between the milk of grazing and non-grazing early lactating Malnad Gidda cows. Various carbohydrates, amino acids, nucleosides and vitamin derivatives were found to be differentially abundant in grazing cows. A total of 35 metabolites were differentially regulated (fold change above 1.5) between the two groups. Tyrosyl-threonine, histidinyl-cysteine, 1-methyladenine,
l
-cysteine and selenocysteine showed fold change above 3 in grazing cows. The lipid profile of milk showed a lesser difference between grazing and non-grazing cows as compared to polar metabolites. To the best of our knowledge, this is the largest inventory of milk metabolomics data of an Indian cattle (
Bos indicus
) breed. We believe that our study would help to emerge a field of Nutri-metabolomics and veterinary omics research.
Journal Article
Quantitative mass spectrometric analysis to unravel glycoproteomic signature of follicular fluid in women with polycystic ovary syndrome
by
Prasad, T. S. Keshava
,
Yelamanchi, Soujanya
,
Mukherjee, Srabani
in
Adult
,
Analysis
,
Angiogenesis
2019
Polycystic ovary syndrome (PCOS) is a complex endocrinopathy affecting women of reproductive age, and whose etiology is not well understood yet. In these women, the follicular growth is arrested at preantral stage leading to cyst formation, consequently resulting in anovulatory infertility in these women. As the follicular fluid provides the conducive microenvironment for the growth of oocytes, molecular profiling of the fluid may provide unique information about pathophysiology associated with follicular development in PCOS. Post-translational addition of oligosaccharide residues is one of the many modifications of secreted proteins influencing their functions. These glycoproteins play a significant role in disease pathology. Despite glycoproteins having such essential functions, very limited information is available on their profiling in human reproductive system, and glycoproteomic profile of follicular fluid of women with PCOS is yet unexplored. In the present study, we performed a comparative glycoproteomic analysis of follicular fluid between women with PCOS and controls undergoing in vitro fertilization, by enrichment of glycoproteins using three different lectins viz. concanavalin A, wheat germ agglutinin and Jacalin. Peptides generated by trypsin digestion were labeled with isobaric tags for relative and absolute quantification reagents and analyzed by liquid chromatography tandem mass spectrometry. We identified 10 differentially expressed glycoproteins, in the follicular fluid of women with PCOS compared to controls. Two important differentially expressed proteins- SERPINA1 and ITIH4, were consistently upregulated and downregulated respectively, upon validation by immunoblotting in follicular fluid and real-time polymerase chain reaction in granulosa cells. These proteins play a role in angiogenesis and extracellular matrix stabilization, vital for follicle maturation. In conclusion, a comparative glycoproteomic profiling of follicular fluid from women with PCOS and controls revealed an altered expression of proteins which may contribute to the defects in follicle development in PCOS pathophysiology.
Journal Article
Kinetic characterization of purified laccase from Trametes hirsuta: a study on laccase catalyzed biotransformation of 1,4-dioxane
2021
ObjectiveLaccase is one of the best known biocatalysts which degrade wide varieties of complex molecules that are both non-cyclic and cyclic in structure. The study focused on enzyme kinetics of a purified laccase from Trametes hirsuta L. fungus and its application on biotransformation of a carcinogenic molecule 1,4-dioxane.ResultsLaccase was purified from white-rot fungus T. hirsuta L. which showed specific activity of 978.34 U/mg after the purification fold of 54.08. The stable laccase activity (up to 16 h) is shown at 4–6 pH and 20–40 °C temperature range. The purified enzyme exhibited significant stability for 10 metal ions up to 10 mM concentration, except for Fe2+ and Hg2+. The Cu2+ ion induced laccase activity up to 142% higher than the control at 10 mM concentration. The laccase enzyme kinetic parameters Km was 20 ± 5 µM and 400 ± 60 µM, whereas Kcat was 198.29 ± 0.18/s and 80.20 ± 1.59/s for 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and guaiacol respectively. The cyclic ether 1,4-dioxane (100 ppm) was completely degraded in presence of purified laccase within 2 h of incubation and it was confirmed by HPLC and GC analysis. The oxidation reaction was accelerated by 25, 22, 6 and 19% in presence of 1 mM syringaldehyde, vanillin, ABTS and guaiacol mediators respectively.ConclusionsIn this study, fungal laccase (a natural biocatalyst) based degradation of synthetic chemical 1,4-dioxane was reported for the first time. This method has added advantages over the multiple methods reported earlier being a natural remedy.
Journal Article
Oral Azacitidine Maintenance Therapy for Acute Myeloid Leukemia in First Remission
by
Porkka, Kimmo
,
Kumar, Keshava
,
Ofran, Yishai
in
Acute myeloid leukemia
,
Administration, Oral
,
Aged
2020
Older patients with acute myeloid leukemia were treated with intensive chemotherapy and then randomly assigned to receive placebo or oral azacitidine (CC-486) daily for 14 days per 28-day cycle. CC-486 was associated with significantly longer relapse-free and overall survival, with some gastrointestinal side effects but maintenance of quality of life.
Journal Article
A Dominant C150Y Mutation in FHL1 Induces Structural Alterations in LIM2 Domain Causing Protein Aggregation In Human and Drosophila Indirect Flight Muscles
by
Narayanappa Gayathri
,
Atchayaram Nalini
,
Mangalaparthi, Kiran K
in
Abnormalities
,
Agglomeration
,
Aggregates
2021
FHL1-related myopathies are rare X-linked dominant myopathies. Though clinically classified into several subgroups, spinal and scapuloperoneal muscle involvement are common to all. In this study, we identified c.449G > A, p.C150Y mutation by clinical exome sequencing in two patients from same family (son and mother) of Indian origin who presented with multiple contractures. Muscle biopsy showed numerous intracytoplasmic aggregates intensely stained on HE and MGT. The strong reactions to M-NBT revealed aggregates to be reducing bodies and positively labeled to anti-FHL1 antibody. Ultrastructurally, Z-band streaming and granular and granulofilamentous material were seen. Further, the translational evidence of mutant peptide was confirmed using mass spectrometric analysis. To establish p.C150Y as the cause for protein aggregation, in vivo studies were carried out using transgenic Drosophila model which highlighted Z-band abnormalities and protein aggregates in indirect flight muscles with compromised physiological function. Thus, recapitulating the X-linked human disease phenotype. Additionally, the molecular dynamics simulation analysis unraveled the drastic change in α-helix of LIM2, the region immediately next to site of C150Y mutation that could be the plausible cause for protein aggregation. To the best of our knowledge, this is the first study of p.C150Y mutation in FHL1 identified in Indian patients with in vivo and in silico analysis to establish the cause for protein aggregation in muscle.
Journal Article
PfCDPK1 mediated signaling in erythrocytic stages of Plasmodium falciparum
by
Gilberger, Tim
,
Ekka, Roseleen
,
Madugundu, Anil K.
in
631/326/417/1716
,
631/45/275
,
631/45/475
2017
Calcium Dependent Protein Kinases are key effectors of calcium signaling in malaria parasite. PfCDPK1 is critical for asexual development of
Plasmodium falciparum
, but its precise function and substrates remain largely unknown. Using a conditional knockdown strategy, we here establish that this kinase is critical for the invasion of host erythrocytes. Furthermore, using a multidisciplinary approach involving comparative phosphoproteomics we gain insights into the underlying molecular mechanisms. We identify substrates of PfCDPK1, which includes proteins of Inner Membrane Complex and glideosome-actomyosin motor assembly. Interestingly, PfCDPK1 phosphorylates PfPKA regulatory subunit (PfPKA-R) and regulates PfPKA activity in the parasite, which may be relevant for the process of invasion. This study delineates the signaling network of PfCDPK1 and sheds light on mechanisms via which it regulates invasion.
Calcium dependent protein kinase 1 (CDPK1) plays an important role in asexual development of
Plasmodium falciparum
. Using phosphoproteomics and conditional knockdown of CDPK1, the authors here identify CDPK1 substrates and a cross-talk between CDPK1 and PKA, and show the role of CDPK1 in parasite invasion.
Journal Article