Pantakani, Dasaradha Venkata Krishna

[["dc.bibliographiccitation.firstpage","527"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","Wiley Interdisciplinary Reviews - RNA"],["dc.bibliographiccitation.lastpage","535"],["dc.bibliographiccitation.volume","5"],["dc.contributor.author","Smorag, Lukasz"],["dc.contributor.author","Xu, X."],["dc.contributor.author","Engel, Wolfgang"],["dc.contributor.author","Pantakani, Dasaradha Venkata Krishna"],["dc.date.accessioned","2018-11-07T09:38:38Z"],["dc.date.available","2018-11-07T09:38:38Z"],["dc.date.issued","2014"],["dc.description.abstract","RNA-binding proteins play an important role in the regulation of gene expression by modulating translation and localization of specific messenger RNAs (mRNAs) during early development and gametogenesis. The DAZ (Deleted in Azoospermia) family of proteins, which includes DAZ, DAZL, and BOULE, are germ cell-specific RNA-binding proteins that are implicated in translational regulation of several transcripts. Of particular importance is DAZL, which is present in vertebrates and arose from the duplication of the ancestral BOULE during evolution. Identification of DAZL target mRNAs and characterization of the RNA-binding sequence through in vitro binding assays and crystallographic studies revealed that DAZL binds to GUU triplets in the 3' untranslated region of target mRNAs. Although there is compelling evidence for the role of DAZL in translation stimulation of target mRNAs, recent studies indicate that DAZL can also function in translational repression and transport of specific mRNAs. Furthermore, apart from the well-characterized function of DAZL in gametogenesis, recent data suggest its role in early embryonic development and differentiation of pluripotent stem cells toward functional gametes. In light of the mounting evidence for the role of DAZL in various cellular and developmental processes, we summarize the currently characterized biological functions of DAZL in RNA biology and development. (C) 2014 John Wiley & Sons, Ltd."],["dc.identifier.doi","10.1002/wrna.1228"],["dc.identifier.isi","000337627700006"],["dc.identifier.pmid","24715697"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/33108"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-blackwell"],["dc.relation.issn","1757-7012"],["dc.relation.issn","1757-7004"],["dc.title","The roles of DAZL in RNA biology and development"],["dc.type","review"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","425"],["dc.bibliographiccitation.issue","5"],["dc.bibliographiccitation.journal","Biochimica et Biophysica Acta (BBA) - Gene Regulatory Mechanisms"],["dc.bibliographiccitation.lastpage","435"],["dc.bibliographiccitation.volume","1829"],["dc.contributor.author","Xu, X."],["dc.contributor.author","Tan, Xiaoying"],["dc.contributor.author","Lin, Qiong"],["dc.contributor.author","Schmidt, Bernhard"],["dc.contributor.author","Engel, Wolfgang"],["dc.contributor.author","Pantakani, Dasaradha Venkata Krishna"],["dc.date.accessioned","2018-11-07T09:25:29Z"],["dc.date.available","2018-11-07T09:25:29Z"],["dc.date.issued","2013"],["dc.description.abstract","Dazl (deleted in azoospermia-like) is an RNA binding protein that is important for germ cell differentiation in vertebrates. In the present study, we report the identification of a novel Dazl isoform (Dazl_Delta 8) that results from alternative splicing of exon8 of mouse Dazl. We observed the expression of Dazl_Delta 8 in various pluripotent cell types, but not in somatic cells. Furthermore, the Dazl_Delta 8 splice variant was expressed along with the full-length isoform of Dazl (Dazl_FL) throughout male germ-cell development and in the ovary. Sub-cellular localization studies of Dazl_Delta 8 revealed a diffused cytoplasmic and large granular pattern, which is similar to the localization patterns of Dazl_FL protein. In contrast to the well documented translation stimulation function in germ cells, overexpression and downregulation studies of Dazl isoforms (Dazl_FL and Dazl_Delta 8) revealed a role for Dazl in the negative translational regulation, of Mvh, a known target of Dazl, as well as Oct3/4 and Sox2 in embryonic stem cells (ESCs). In line with these observations, a luciferase reporter assay with the 3'UTRs of Oct3/4 and Mvh confirmed the translational repressive role of Dazl isoforms in ESCs but not in germ cells derived cell line GC-1. Further, we identified several putative target mRNAs of Dazl_FL and Dazl_Delta 8 in ESCs through RNA-binding immunoprecipitation followed by whole genome transcriptome analysis. Collectively, our results show a translation repression function of Dazl in pluripotent stem cells. (C) 2013 Elsevier B.V. All rights reserved."],["dc.identifier.doi","10.1016/j.bbagrm.2012.12.010"],["dc.identifier.isi","000318134500001"],["dc.identifier.pmid","23298641"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/30075"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Bv"],["dc.relation.issn","1874-9399"],["dc.title","Mouse Dazl and its novel splice variant functions in translational repression of target mRNAs in embryonic stem cells"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1045"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Stem Cell Research"],["dc.bibliographiccitation.lastpage","1059"],["dc.bibliographiccitation.volume","11"],["dc.contributor.author","Tan, Xiaoying"],["dc.contributor.author","Xu, X."],["dc.contributor.author","Elkenani, Manar"],["dc.contributor.author","Smorag, Lukasz"],["dc.contributor.author","Zechner, Ulrich"],["dc.contributor.author","Nolte, Jessica"],["dc.contributor.author","Engel, Wolfgang"],["dc.contributor.author","Pantakani, Dasaradha Venkata Krishna"],["dc.date.accessioned","2018-11-07T09:17:54Z"],["dc.date.available","2018-11-07T09:17:54Z"],["dc.date.issued","2013"],["dc.description.abstract","Pluripotency is maintained by both known and unknown transcriptional regulatory networks. In the present study, we have identified Zfp819, a KRAB-zinc finger protein, as a novel pluripotency-related factor and characterized its role in pluripotent stem cells. We show that Zfp819 is expressed highly in various types of pluripotent stem cells but not in their differentiated counterparts. We identified the presence of non-canonical nuclear localization signals in particular zinc finger motifs and identified them as responsible for the nuclear localization of Zfp819. Analysis of the Zfp819 promoter region revealed the presence of a transcriptionally active chromatin signature. Moreover, we confirmed the binding of pluripotency-related factors, Oct4, Sox2, and Nanog to the distal promoter region of Zfp819, indicating that the expression of this gene is regulated by a pluripotency transcription factor network. We found that the expression of endogenous retroviral elements (ERVs) such as Intracisternal A Particle (IAP) retrotransposons, Long Interspersed Nuclear Elements (LINE1), and Short Interspersed Nuclear Elements (SINE B1) is significantly upregulated in Zfp819-knockdown (Zfp819_KD) cells. In line with the activation of ERVs, we observed the occurrence of spontaneous DNA damage in Zfp819_KD cells. Furthermore, we tested whether Zfp819 can interact with KAP1, a KRAB-associated protein with a transcriptional repression function, and found the interaction between these two proteins in both in vitro and in vivo experiments. The challenging of Zfp819_KD cells with DNA damaging agent revealed that these cells are inefficient in repairing the damaged DNA, as cells showed presence of gamma H2A.X foci for a prolonged time. Collectively, our study identified Zfp819 as a novel pluripotency-related factor and unveiled its function in genomic integrity maintenance mechanisms of mouse embryonic stem cells. (C) 2013 Elsevier B.V. All rights reserved."],["dc.identifier.doi","10.1016/j.scr.2013.07.006"],["dc.identifier.isi","327905300008"],["dc.identifier.pmid","23954693"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/28283"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Bv"],["dc.relation.issn","1876-7753"],["dc.relation.issn","1873-5061"],["dc.title","Zfp819, a novel KRAB-zinc finger protein, interacts with KAP1 and functions in genomic integrity maintenance of mouse embryonic stem cells"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","166"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","MHR Basic science of reproductive medicine"],["dc.bibliographiccitation.lastpage","174"],["dc.bibliographiccitation.volume","17"],["dc.contributor.author","Khromov, Tatjana"],["dc.contributor.author","Pantakani, Dasaradha Venkata Krishna"],["dc.contributor.author","Nolte, Jessica"],["dc.contributor.author","Wolf, Marieke"],["dc.contributor.author","Dressel, Ralf"],["dc.contributor.author","Engel, Wolfgang"],["dc.contributor.author","Zechner, Ulrich"],["dc.date.accessioned","2018-11-07T08:58:57Z"],["dc.date.available","2018-11-07T08:58:57Z"],["dc.date.issued","2011"],["dc.description.abstract","We previously reported the generation of multipotent adult germline stem cells (maGSCs) from spermatogonial stem cells (SSCs) isolated from adult mouse testis. In a later study, we substantiated the pluripotency of maGSCs by demonstrating their close similarity to pluripotent male embryonic stem cells (ESCs) at the epigenetic level of global and gene-specific DNA methylation. Here, we extended the comparative epigenetic analysis of maGSCs and male ESCs by investigating the second main epigenetic modification in mammals, i.e. global and gene-specific modifications of histones (H3K4 trimethylation, H3K9 acetylation, H3K9 trimethylation and H3K27 trimethylation). Using immunofluorescence staining, flow cytometry and western blot analysis, we show that maGSCs are very similar to male ESCs with regard to global levels and nuclear distribution patterns of these modifications. Chromatin immunoprecipitation real-time PCR analysis of these modifications at the gene-specific level further revealed modification patterns of the pluripotency marker genes Oct4, Sox2 and Nanog in maGSCs that are nearly identical to those of male ESCs. These genes were enriched for activating histone modifications including H3K4me3 and H3K9ac and depleted of repressive histone modifications including H3K27me3 and H3K9me3. In addition, Hoxa11, a key regulator of early embryonic development showed the ESC-typical bivalent chromatin conformation with enrichment of both the activating H3K4me3 and the repressive H3K27me3 modification also in maGSCs. Collectively, our results demonstrate that maGSCs also closely resemble ESCs with regard to their chromatin state and further evidence their pluripotent nature."],["dc.identifier.doi","10.1093/molehr/gaq085"],["dc.identifier.isi","000287257000003"],["dc.identifier.pmid","20935159"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/23771"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Oxford Univ Press"],["dc.relation.issn","1360-9947"],["dc.title","Global and gene-specific histone modification profiles of mouse multipotent adult germline stem cells"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1664"],["dc.bibliographiccitation.issue","8"],["dc.bibliographiccitation.journal","Journal of Investigative Dermatology"],["dc.bibliographiccitation.lastpage","1671"],["dc.bibliographiccitation.volume","136"],["dc.contributor.author","Elkenani, Manar"],["dc.contributor.author","Nyamsuren, Gunsmaa"],["dc.contributor.author","Raju, Priyadharsini"],["dc.contributor.author","Liakath-Ali, Kifayathullah"],["dc.contributor.author","Hamdaoui, Aicha"],["dc.contributor.author","Kata, Aleksandra"],["dc.contributor.author","Dressel, Ralf"],["dc.contributor.author","Klonisch, Thomas"],["dc.contributor.author","Watt, Fiona M."],["dc.contributor.author","Engel, Wolfgang"],["dc.contributor.author","Thliveris, James A."],["dc.contributor.author","Pantakani, Dasaradha Venkata Krishna"],["dc.contributor.author","Adham, Ibrahim M."],["dc.date.accessioned","2018-11-07T10:11:05Z"],["dc.date.available","2018-11-07T10:11:05Z"],["dc.date.issued","2016"],["dc.description.abstract","The depletion of evolutionarily conserved pelota protein causes impaired differentiation of embryonic and spermatogonial stem cells. In this study, we show that temporal deletion of pelota protein before epidermal barrier acquisition leads to neonatal lethality due to perturbations in permeability barrier formation. Further analysis indicated that this phenotype is a result of failed processing of profilaggrin into filaggrin monomers, which promotes the formation of a protective epidermal layer. Molecular analyses showed that pelota protein negatively regulates the activities of bone morphogenetic protein and phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling pathways in the epidermis. To address whether elevated activities of bone morphogenetic protein and PI3K/AKT signaling pathways were the cause for the perturbed epidermal barrier in Pelo-deficient mice, we made use of organotypic cultures of skin explants from control and mutant embryos at embryonic day 15.5. Inhibition of PI3K/AKT signaling did not significantly affect the bone morphogenetic protein activity. However, inhibition of bone morphogenetic protein signaling caused a significant attenuation of PI3K/AKT activity in mutant skin and, more interestingly, the restoration of profilaggrin processing and normal epidermal barrier function. Therefore, increased activity of the PI3K/AKT signaling pathway in Pelo-deficient skin might conflict with the dephosphorylation of profilaggrin and thereby affect its proper processing into filaggrin monomers and ultimately the epidermal differentiation."],["dc.description.sponsorship","Medical Research Council [G1100073, MR/L022699/1]"],["dc.identifier.doi","10.1016/j.jid.2016.04.020"],["dc.identifier.isi","000380585200092"],["dc.identifier.pmid","27164299"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/39976"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Inc"],["dc.relation.issn","1523-1747"],["dc.relation.issn","0022-202X"],["dc.title","Pelota Regulates Epidermal Differentiation by Modulating BMP and PI3K/AKT Signaling Pathways"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]