@article {683, title = {Combinatorial action of Grainyhead, Extradenticle and Notch in regulating Hox mediated apoptosis in Drosophila larval CNS.}, journal = {PLoS Genet}, volume = {13}, year = {2017}, month = {2017 Oct}, pages = {e1007043}, abstract = {

Hox mediated neuroblast apoptosis is a prevalent way to pattern larval central nervous system (CNS) by different Hox genes, but the mechanism of this apoptosis is not understood. Our studies with Abdominal-A (Abd-A) mediated larval neuroblast (pNB) apoptosis suggests that AbdA, its cofactor Extradenticle (Exd), a helix-loop-helix transcription factor Grainyhead (Grh), and Notch signaling transcriptionally contribute to expression of RHG family of apoptotic genes. We find that Grh, AbdA, and Exd function together at multiple motifs on the apoptotic enhancer. In vivo mutagenesis of these motifs suggest that they are important for the maintenance of the activity of the enhancer rather than its initiation. We also find that Exd function is independent of its known partner homothorax in this apoptosis. We extend some of our findings to Deformed expressing region of sub-esophageal ganglia where pNBs undergo a similar Hox dependent apoptosis. We propose a mechanism where common players like Exd-Grh-Notch work with different Hox genes through region specific enhancers to pattern respective segments of larval central nervous system.

}, keywords = {Amino Acid Sequence, Animals, Apoptosis, Central Nervous System, DNA-Binding Proteins, Drosophila, Drosophila Proteins, Enhancer Elements, Genetic, Female, Gene Expression Regulation, Developmental, Genes, Homeobox, Homeodomain Proteins, Larva, Male, Nuclear Proteins, Receptors, Notch, Transcription Factors}, issn = {1553-7404}, doi = {10.1371/journal.pgen.1007043}, author = {Khandelwal, Risha and Sipani, Rashmi and Govinda Rajan, Sriivatsan and Kumar, Raviranjan and Joshi, Rohit} } @article {513, title = {L-Plastin S-glutathionylation promotes reduced binding to β-actin and affects neutrophil functions. (Mass Spectrometry)}, journal = {Free Radic Biol Med}, volume = {86}, year = {2015}, month = {2015 Sep}, pages = {1-15}, abstract = {

Posttranslational modifications (PTMs) of cytoskeleton proteins due to oxidative stress associated with several pathological conditions often lead to alterations in cell function. The current study evaluates the effect of nitric oxide (DETA-NO)-induced oxidative stress-related S-glutathionylation of cytoskeleton proteins in human PMNs. By using in vitro and genetic approaches, we showed that S-glutathionylation of L-plastin (LPL) and β-actin promotes reduced chemotaxis, polarization, bactericidal activity, and phagocytosis. We identified Cys-206, Cys-283, and Cys-460as S-thiolated residues in the β-actin-binding domain of LPL, where cys-460 had the maximum score. Site-directed mutagenesis of LPL Cys-460 further confirmed the role in the redox regulation of LPL. S-Thiolation diminished binding as well as the bundling activity of LPL. The presence of S-thiolated LPL was detected in neutrophils from both diabetic patients and db/db mice with impaired PMN functions. Thus, enhanced nitroxidative stress may results in LPL S-glutathionylation leading to impaired chemotaxis, polarization, and bactericidal activity of human PMNs, providing a mechanistic basis for their impaired functions in diabetes mellitus.

}, keywords = {Actins, Adult, Amino Acid Sequence, Animals, Case-Control Studies, Cell Polarity, Chemotaxis, Diabetes Mellitus, Female, Glutathione, HEK293 Cells, Humans, Male, Mice, Inbred C57BL, Mice, Obese, Microfilament Proteins, Middle Aged, Molecular Sequence Data, Neutrophils, Nitric Oxide, Oxidative Stress, Protein Binding, Protein Processing, Post-Translational, Young Adult}, issn = {1873-4596}, doi = {10.1016/j.freeradbiomed.2015.04.008}, author = {Dubey, Megha and Singh, Abhishek K and Awasthi, Deepika and Nagarkoti, Sheela and Kumar, Sachin and Ali, Wahid and Chandra, Tulika and Kumar, Vikas and Barthwal, Manoj K and Jagavelu, Kumaravelu and S{\'a}nchez-G{\'o}mez, Francisco J and Lamas, Santiago and Dikshit, Madhu} } @article {519, title = {Unexpected histone H3 tail-clipping activity of glutamate dehydrogenase. (Mass spectrometry - Proteomics)}, journal = {J Biol Chem}, volume = {288}, year = {2013}, month = {2013 Jun 28}, pages = {18743-57}, abstract = {

Clipping of histone tails has been reported in several organisms. However, the significance and regulation of histone tail clipping largely remains unclear. According to recent discoveries H3 clipping has been found to be involved in regulation of gene expression and chromatin dynamics. Earlier we had provided evidence of tissue-specific proteolytic processing of histone H3 in White Leghorn chicken liver nuclei. In this study we identify a novel activity of glutamate dehydrogenase (GDH) as a histone H3-specific protease in chicken liver tissue. This protease activity is regulated by divalent ions and thiol-disulfide conversion in vitro. GDH specifically clips H3 in its free as well as chromatin-bound form. Furthermore, we have found an inhibitor that inhibits the H3-clipping activity of GDH. Like previously reported proteases, GDH too may have the potential to regulate/modulate post-translational modifications of histone H3 by removing the N-terminal residues of the histone. In short, our findings identify an unexpected proteolytic activity of GDH specific to histone H3 that is regulated by redox state, ionic concentrations, and a cellular inhibitor in vitro.

}, keywords = {Amino Acid Sequence, Animals, Binding Sites, Brain, Chickens, Chromatin, Cysteine Proteases, Disulfides, Epigenesis, Genetic, Gene Expression Regulation, Enzymologic, Glutamate Dehydrogenase, Histones, Hydrogen-Ion Concentration, Liver, Mass Spectrometry, Mice, Molecular Sequence Data, Rats, Recombinant Proteins, Salts, Sulfhydryl Compounds, Temperature}, issn = {1083-351X}, doi = {10.1074/jbc.M113.462531}, author = {Mandal, Papita and Verma, Naveen and Chauhan, Sakshi and Tomar, Raghuvir S} } @article {718, title = {Development of the structural core and of conformational heterogeneity during the conversion of oligomers of the mouse prion protein to worm-like amyloid fibrils.}, journal = {J Mol Biol}, volume = {423}, year = {2012}, month = {2012 Oct 19}, pages = {217-31}, abstract = {

Understanding how structure develops during the course of amyloid fibril formation by the prion protein is important for understanding prion diseases. Determining how conformational heterogeneity manifests itself in the fibrillar and pre-fibrillar amyloid aggregates is critical for understanding prion strain phenotypes. In this study, the formation of worm-like amyloid fibrils by the mouse prion protein has been characterized structurally by hydrogen-deuterium exchange coupled to mass spectrometry. The structural cores of these fibrils and of the oligomer on the direct pathway of amyloid fibril formation have been defined, showing how structure develops during fibril formation. The structural core of the oligomer not on the direct pathway has also been defined, allowing the delineation of the structural features that make this off-pathway oligomer incompetent to directly form fibrils. Sequence segments that exhibit multiple local conformations in the three amyloid aggregates have been identified, and the development of structural heterogeneity during fibril formation has been characterized. It is shown that conformational heterogeneity is not restricted to only the C-terminal domain region, which forms the structural core of the aggregates; it manifests itself in the N-terminal domain of the protein as well. Importantly, all three amyloid aggregates are shown to be capable of disrupting lipid membrane structure, pointing to a mechanism by which they may be toxic.

}, keywords = {Amino Acid Sequence, Amyloid, Animals, Deuterium Exchange Measurement, Kinetics, Mice, Models, Molecular, Molecular Sequence Data, Prion Proteins, Prions, Protein Conformation, Protein Folding}, issn = {1089-8638}, doi = {10.1016/j.jmb.2012.06.040}, author = {Singh, Jogender and Sabareesan, A T and Mathew, M K and Udgaonkar, Jayant B} } @article {712, title = {An inhibitor of nonhomologous end-joining abrogates double-strand break repair and impedes cancer progression.}, journal = {Cell}, volume = {151}, year = {2012}, month = {2012 Dec 21}, pages = {1474-87}, abstract = {

DNA Ligase IV is responsible for sealing of double-strand breaks (DSBs) during nonhomologous end-joining (NHEJ). Inhibiting Ligase IV could result in amassing of DSBs, thereby serving as a strategy toward treatment of cancer. Here, we identify a molecule, SCR7 that inhibits joining of DSBs in cell-free repair system. SCR7 blocks Ligase IV-mediated joining by interfering with its DNA binding but not that of T4 DNA Ligase or Ligase I. SCR7 inhibits NHEJ in a Ligase IV-dependent manner within cells,\ and activates the intrinsic apoptotic pathway. More importantly, SCR7 impedes tumor progression in mouse models and when coadministered with DSB-inducing therapeutic modalities enhances their sensitivity significantly. This inhibitor to target NHEJ offers a strategy toward the treatment of cancer and improvement of existing regimens.

}, keywords = {Amino Acid Sequence, Animals, Cell Line, Tumor, Disease Models, Animal, DNA Breaks, Double-Stranded, DNA End-Joining Repair, DNA Ligase ATP, DNA Ligases, Drug Design, Drug Resistance, Neoplasm, Humans, Lymphocytes, Lymphoma, Male, Mice, Mice, Inbred BALB C, Mice, Nude, Models, Molecular, Molecular Sequence Data, Neoplasms, Protein Structure, Tertiary, Pyrimidines, Radiation Tolerance, Rats, Schiff Bases, Sequence Alignment}, issn = {1097-4172}, doi = {10.1016/j.cell.2012.11.054}, author = {Srivastava, Mrinal and Nambiar, Mridula and Sharma, Sheetal and Karki, Subhas S and Goldsmith, G and Hegde, Mahesh and Kumar, Sujeet and Pandey, Monica and Singh, Ram K and Ray, Pritha and Natarajan, Renuka and Kelkar, Madhura and De, Abhijit and Choudhary, Bibha and Raghavan, Sathees C} }