Springer protocols feed by Genetics/Genomics 
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This is an RSS file. You can use it to subscribe to this data in your favourite RSS reader or to display this data on your own website or blog.Morphometric Analysis of Huntington’s Disease Neurodegeneration in Drosophila
Huntington’s disease (HD) is an autosomal dominant neurodegenerative disorder. The HD gene encodes the huntingtin protein (HTT) that contains polyglutamine tracts of variable length. Expansions of the CAG repeat near the amino terminus to encode 40 or more glutamines (polyQ) lead to disease. At least eight other expanded polyQ diseases have been described [1]. HD can be faithfully modeled in Drosophila with the key features of the disease such as late onset, slowly progressing degeneration, formation of abnormal protein aggregates and the dependence on polyQ length being evident. Such invertebrate model organisms pro...
Source: Springer protocols feed by Genetics/Genomics - June 3, 2013 Category: Genetics & Stem Cells Source Type: news
Atomic Force Microscopy Assays for Evaluating Polyglutamine Aggregation in Solution and on Surfaces
Mutations which cause an expansion of CAG triplet repeats encoding polyglutamine (polyQ) are responsible for the subsequent misfolding of specific proteins that contribute directly to the pathogenesis of at least nine neurodegenerative disorders, including Huntington’s disease (HD) and the spinocerebellar ataxias (SCAs). Expansion of polyQ tracts results in the aggregation of these proteins, potentially through a variety of precursor aggregates, into fibrillar structures. There may also be a variety of aggregates formed that are off-pathway to the formation of fibrils. Here, detailed protocols for analyzing the aggre...
Source: Springer protocols feed by Genetics/Genomics - June 3, 2013 Category: Genetics & Stem Cells Source Type: news
Longitudinal Imaging and Analysis of Neurons Expressing Polyglutamine-Expanded Proteins
Misfolded proteins have been implicated in most of the major neurodegenerative diseases, and identifying drugs and pathways that protect neurons from the toxicity of misfolded proteins is of paramount importance. We invented a form of automated imaging and analysis called robotic microscopy that is well suited to the study of neurodegeneration. It enables the monitoring of large cohorts of individual neurons over their lifetimes as they undergo neurodegeneration. With automated analysis, multiple endpoints in neurons can be measured, including survival. Statistical approaches, typically reserved for engineering and clinica...
Source: Springer protocols feed by Genetics/Genomics - June 3, 2013 Category: Genetics & Stem Cells Source Type: news
Cell Biological Approaches to Investigate Polyglutamine-Expanded AR Metabolism
Spinal and bulbar muscular atrophy (SBMA) is a late-onset neurodegenerative disease caused by a polyglutamine expansion in the androgen receptor (AR). In vivo and in vitro studies have suggested that some steps of normal AR function and metabolism, such as hormone binding and nuclear translocation of the AR, are necessary for toxicity and aggregation of the mutant protein. Mutation of discreet functional domains of the AR and sites of posttranslational modification enable the detailed analysis of the role of AR function and metabolism in toxicity and aggregation of polyglutamine-expanded AR. This analysis could potentially...
Source: Springer protocols feed by Genetics/Genomics - June 3, 2013 Category: Genetics & Stem Cells Source Type: news
Detecting Soluble PolyQ Oligomers and Investigating Their Impact on Living Cells Using Split-GFP
Aberrant expansion of the number of polyglutamine (polyQ) repeats in mutant proteins is the hallmark of various diseases. These pathologies include Huntington’s disease (HD), a neurological disorder caused by expanded polyQ stretch within the huntingtin (Htt) protein. The expansions increase the propensity of the Htt protein to oligomerize. In the cytoplasm of living cells, the mutant form of Htt (mHtt) is present as soluble monomers and oligomers as well as insoluble aggregates termed inclusion bodies (IBs). Detecting and assessing the relative toxicity of these various forms of mHtt has proven difficult. To enable ...
Source: Springer protocols feed by Genetics/Genomics - June 3, 2013 Category: Genetics & Stem Cells Source Type: news
A Bioinformatics Method for Identifying Q/N-Rich Prion-Like Domains in Proteins
Numerous proteins contain domains that are enriched in glutamine and asparagine residues, and aggregation of some of these proteins has been linked to both prion formation in yeast and a number of human diseases. Unfortunately, predicting whether a given glutamine/asparagine-rich protein will aggregate has proven difficult. Here we describe a recently developed algorithm designed to predict the aggregation propensity of glutamine/asparagine-rich proteins. We discuss the basis for the algorithm, its limitations, and usage of recently developed online and downloadable versions of the algorithm. (Source: Springer protocols fe...
Source: Springer protocols feed by Genetics/Genomics - June 3, 2013 Category: Genetics & Stem Cells Source Type: news
Kinetic Analysis of Aggregation Data
Aggregation of repeat-containing proteins is associated with neurodegenerative disorders; a specific example is the established link between expansion of the polyglutamine domain in huntingtin and the appearance of nuclear inclusions in Huntington’s disease. This connection between aggregation and pathology has motivated numerous investigations into the kinetics of aggregation. Quantitative analysis of kinetic data is needed both for comparative purposes (e.g., to compare the effect of different compounds on aggregation kinetics) and for mechanistic insight. Here we describe some analytical equations that can be used...
Source: Springer protocols feed by Genetics/Genomics - June 3, 2013 Category: Genetics & Stem Cells Source Type: news
Analyzing Modifiers of Protein Aggregation in C. elegans by Native Agarose Gel Electrophoresis
The accumulation of specific aggregation-prone proteins during aging is thought to be involved in several diseases, most notably Alzheimer’s and Parkinson’s disease as well as polyglutamine expansion disorders such as Huntington’s disease. Caenorhabditis elegans disease models with transgenic expression of fluorescently tagged aggregation-prone proteins have been used to screen for genetic modifiers of aggregation. To establish the role of modifying factors in the generation of aggregation intermediates, a method has been developed using native agarose gel electrophoresis (NAGE) that enables parallel scre...
Source: Springer protocols feed by Genetics/Genomics - June 3, 2013 Category: Genetics & Stem Cells Source Type: news
Modeling and Analysis of Repeat RNA Toxicity in Drosophila
Expansion of repeat sequences beyond a pathogenic threshold is the cause of a series of dominantly inherited neurodegenerative diseases that includes Huntington’s disease, several spinocerebellar ataxias, and myotonic dystrophy types 1 and 2. Expansion of repeat sequences occurring in coding regions of various genes frequently produces an expanded polyglutamine tract that is thought to result in a toxic protein. However, in a number of diseases that present with similar clinical symptoms, the expansions occur in untranslated regions of the gene that cannot encode toxic peptide products. As expanded repeat-containing ...
Source: Springer protocols feed by Genetics/Genomics - June 3, 2013 Category: Genetics & Stem Cells Source Type: news
Immuno-based Detection Assays to Quantify Distinct Mutant Huntingtin Conformations in Biological Samples
A pathological hallmark of many protein-misfolding diseases is the formation of insoluble aggregates. Quantitative methods are needed to better resolve and define the formation, aggregation, and temporal dynamics of soluble misfolded proteins in native settings. In this book chapter we describe simple and sensitive detection methods to characterize high ordered aggregates (AGERA) and subsets of distinct soluble aggregates (SEC-FRET) of mutant huntingtin protein in biological samples. (Source: Springer protocols feed by Genetics/Genomics)
Source: Springer protocols feed by Genetics/Genomics - June 3, 2013 Category: Genetics & Stem Cells Source Type: news
Yeast as a Platform to Explore Polyglutamine Toxicity and Aggregation
Protein misfolding is associated with many neurodegenerative diseases, including neurodegenerative diseases caused by polyglutamine expansion proteins, such as Huntington’s disease. The model organism baker’s yeast (Saccharomyces cerevisiae) has provided important general insights into the basic cellular mechanisms underlying protein misfolding. Furthermore, experiments in yeast have identified cellular factors that modulate the toxicity and the aggregation associated with polyglutamine expansion proteins. Notably, many features discovered in yeast have been proven to be highly relevant in other model organisms...
Source: Springer protocols feed by Genetics/Genomics - June 3, 2013 Category: Genetics & Stem Cells Source Type: news
Molecular Pathology of Polyalanine Expansion Disorders: New Perspectives from Mouse Models
Disease-causing polyalanine (PA) expansion mutations have been identified in nine genes, eight of which encode transcription factors (TFs) with important roles in development. In vitro and cell overexpression studies have shown that expanded PA tracts result in protein misfolding and the formation of aggregates. This feature of PA proteins is reminiscent of the related polyglutamine (PQ) disease proteins, which have been shown to cause disease via a gain-of-function (GOF) mechanism. However, in sharp contrast to PQ disorders, the disease phenotypes associated with PA mutations are more consistent with a LOF and/or mild GOF...
Source: Springer protocols feed by Genetics/Genomics - June 3, 2013 Category: Genetics & Stem Cells Source Type: news
Evolution of Olfactory Receptors
Olfactory receptors are a specialized set of receptor cells responsible for the detection of odors. These cells are G protein-coupled receptors and expressed in the cell membranes of olfactory sensory neurons. Once a cell is activated by a ligand, it initiates a signal transduction cascade that produces a nerve impulse to the brain where odor perception is processed. Vertebrate olfactory evolution is characterized by birth-and-death events, a special case of the stochastic continuous time Markov process. Vertebrate fish have three general types of receptor cells (two dedicated to pheromones). Terrestrial animals have diffe...
Source: Springer protocols feed by Genetics/Genomics - April 19, 2013 Category: Genetics & Stem Cells Source Type: news
Deorphanization of Human Olfactory Receptors by Luciferase and Ca-Imaging Methods
Olfactory receptors (ORs) are expressed at the cell surfaces of olfactory sensory neurons lining the olfactory epithelium and are the first actors for the perception and recognition of odorants. (Source: Springer protocols feed by Genetics/Genomics)
Source: Springer protocols feed by Genetics/Genomics - April 19, 2013 Category: Genetics & Stem Cells Source Type: news
Visualizing Olfactory Receptor Expression and Localization in Drosophila
Odor detection and discrimination by olfactory systems in vertebrates and invertebrates depend both on the selective expression of individual olfactory receptor genes in subpopulations of olfactory sensory neurons, and on the targeting of the encoded proteins to the exposed, ciliated endings of sensory dendrites. Techniques to visualize the expression and localization of olfactory receptor gene products in vivo have been essential to reveal the molecular logic of peripheral odor coding and to permit investigation of the developmental and cellular neurobiology of this sensory system. Here, we describe methods for detection ...
Source: Springer protocols feed by Genetics/Genomics - April 19, 2013 Category: Genetics & Stem Cells Source Type: news
