Project description:Transcriptome profiling of Lir3 C.elegans mutants. Larval stage L4 worms were used for RNA isolation from N2 (Bristol), Q40 (polyglutamine model) genetic background; Lir3 and wiltype controls. Experiments were done in triplicates using ribosomal RNA depletion. Libraries were sequenced with 50bp reads on Illumina HiSeq2500 platform
Project description:The poorly conserved N-terminal half of TATA binding protein (TBP) harbours a polyglutamine stretch of 29 to 42 in normal individuals. Expansion of this stretch leading to more than 42 is associated with a neurodegenerative disorder spinocerebellar ataxia 17 (SCA17). This study compares the espression profile of mouse neuro 2a cells expressing a vector control and TBP varient with 59 polyglutamines known to form intra nuclear aggregates. Keywords: Neuro 2a, SCA17, TBP, polyglutamine
Project description:Expansion of a polyglutamine (polyQ) tract in the gene for the androgen receptor (AR) results in partial loss of transactivation function and causes spinobulbar muscular atrophy (SBMA). Modification of AR by small ubiquitin-like modifier (SUMO) reduces AR function in a promoter context-dependent manner. We used microarrays to confirm and demonstrate loss of AR function from polyQ expansion and to test the degree to which AR function is altered by preventing polyQ AR SUMOylation.
Project description:Expansion of a polyglutamine (polyQ) tract in the gene for the androgen receptor (AR) results in partial loss of transactivation function and causes spinobulbar muscular atrophy (SBMA). Modification of AR by small ubiquitin-like modifier (SUMO) reduces AR function in a promoter context-dependent manner. We used microarrays to confirm and demonstrate loss of AR function from polyQ expansion and to test the degree to which AR function is altered by preventing polyQ AR SUMOylation. PC12 cells expressing AR10Q, AR112Q, or nonSUMOylatable AR112Q (KRKR) in the presence or absence of synthetic androgen R1881 were assessed for alterations in AR function by comparing gene expression changes with each AR variant in response to ligand.
Project description:Polyglutamine(polyQ) expansion of α1A voltage-dependent calcium channel (Cav2.1) is the causative mutation of spinocerebellar ataxia type 6 (SCA6). The C-terminal fragment (CTF) of Cav2.1 makes aggregates in the cytoplasm of SCA6 Purkinje cells and may relate to the pathogenesis. In order to identify genes associated with polyQ expansion and subcellular localization of CTF, we analyzed gene expression profiles of PC12 rat pheochromocytoma cells using Tet-off system.
Project description:Huntington’s disease is a monogenic disorder, with only one known causative gene, huntingtin (HTT). Expansion of a trinucleotide (CAG) repeat within the HTT gene results in a mutant protein containing polyglutamine (polyQ) stretches. While mutant HTT is the primary driver of cellular degeneration in the brain, the molecular and cellular mechanisms are incompletely understood. To further understand the role of polyQ in disease pathogenesis, we studied the dynamics of HTT protein-protein interactions (PPIs) in the striatum of mice with wild-type (Q20) and mutant (Q140) HTT at pre-symptomatic and manifest HD ages using label-free and isotope-labeled IP-MS approaches. Combining these approaches, we demonstrated that HTT PPI dynamics are distinct in early and later disease phases. Computational analysis pointed to early protein interaction changes involving synaptic transmission and vesicle fusion functions, while later interactions underlie changes in synapse morphogenesis and impact the actin cytoskeletal network.
Project description:Polyglutamine(polyQ) expansion of ?1A voltage-dependent calcium channel (Cav2.1) is the causative mutation of spinocerebellar ataxia type 6 (SCA6). The C-terminal fragment (CTF) of Cav2.1 makes aggregates in the cytoplasm of SCA6 Purkinje cells and may relate to the pathogenesis. In order to identify genes associated with polyQ expansion and subcellular localization of CTF, we analyzed gene expression profiles of PC12 rat pheochromocytoma cells using Tet-off system. We exmined gene expression profiles of Tet-off PC12 cells using the following four recombinant C-terminal fragments (rCTFs): rCTF-Q13-NLS, rCTF-Q13-NES, rCTF-Q28-NLS and rCTF-Q28-NES. We obtained gene expression data of both Dox (+) and Dox (-) conditions for each CTF. All assays were performed in duplicate.
Project description:Huntington’s disease results from expansion of a glutamine-coding CAG tract in the huntingtin (HTT) gene, producing an aberrantly functioning form of HTT. Both wildtype and disease-state HTT form a hetero-dimer with HAP40 of unknown functional relevance. We demonstrate in vivo and in cell models that HTT and HAP40 cellular abundance are coupled. Integrating data from a 2.6 Å cryo-electron microscopy structure, cross-linking mass spectrometry, small-angle X-ray scattering, and modeling, we provide a near-atomic-level view of HTT, its molecular interaction surfaces and compacted domain architecture, orchestrated by HAP40. Native mass-spectrometry reveals a remarkably stable hetero-dimer, potentially explaining the cellular inter-dependence of HTT and HAP40. The exon 1 region of HTT is dynamic but shows greater conformational variety in the polyglutamine expanded mutant than wildtype exon 1. Our data provide a foundation for future functional and drug discovery studies targeting Huntington’s disease and illuminate the structural consequences of HTT polyglutamine expansion.
Project description:Huntington’s disease results from expansion of a glutamine-coding CAG tract in the huntingtin (HTT) gene, producing an aberrantly functioning form of HTT. Both wildtype and disease-state HTT form a hetero-dimer with HAP40 of unknown functional relevance. We demonstrate in vivo and in cell models that HTT and HAP40 cellular abundance are coupled. Integrating data from a 2.6 Å cryo-electron microscopy structure, cross-linking mass spectrometry, small-angle X-ray scattering, and modeling, we provide a near-atomic-level view of HTT, its molecular interaction surfaces and compacted domain architecture, orchestrated by HAP40. Native mass-spectrometry reveals a remarkably stable hetero-dimer, potentially explaining the cellular inter-dependence of HTT and HAP40. The exon 1 region of HTT is dynamic but shows greater conformational variety in the polyglutamine expanded mutant than wildtype exon 1. Our data provide a foundation for future functional and drug discovery studies targeting Huntington’s disease and illuminate the structural consequences of HTT polyglutamine expansion.
Project description:Stem cells in many systems, including Drosophila germline stem cells (GSCs), have increased ribosome biogenesis and translation during terminal differentiation. Here, we show that pseudouridylation of ribosomal RNA (rRNA) mediated by the H/ACA box is required for ribosome biogenesis and oocyte specification. Reducing ribosome levels during differentiation decreased the translation of a subset of mRNAs that are enriched for CAG repeats and encodes polyglutamine-containing proteins, including differentiation factors such as RNA-binding Fox protein 1. Moreover, ribosomes were enriched at CAG repeats within transcripts during oogenesis. Increasing TOR activity to elevate ribosome levels in H/ACA box-depleted germlines suppressed the GSC differentiation defects, whereas germlines treated with the TOR inhibitor rapamycin had reduced levels of polyglutamine-containing proteins. Thus, ribosome biogenesis and ribosome levels can control stem cell differentiation via selective translation of CAG repeat-containing transcripts.