The platform for antibody characterization used to carry out this study was endorsed by a committee of industry and academic representatives. antibody characterization, antibody validation, western blot, immunoprecipitation, immunofluorescence == Introduction == Huntingtons Disease (HD) is usually a neurodegenerative disorder inherited in an autosomal dominant manner, presenting with a spectrum of progressive motor, cognitive, and psychological impairments, typically with adult-onset of symptoms.1Although the HD causative gene,HTT, was discovered over three decades ago, there are still no disease-modifying treatments available for patients, and progress unpicking the molecular pathology of the disease remains slow.2 HD arises from a heterozygous growth mutation of the trinucleotide CAG repeat tract in exon Oroxin B 1 ofHTT, located on chromosome 4, above a critical threshold of ~36 repeats. This mutation results in growth Oroxin B of the polyglutamine stretch at the N-terminus of the 3144 amino acid Huntingtin protein. Huntingtin functions as a scaffold protein, engaging in considerable protein-protein interactions,3forming numerous multi-protein complexes to carry-out its diverse array of functions. Modulation of this interaction network by the polyglutamine growth contributes to degeneration within the central nervous system, affecting medium spiny neurons at the onset of disease.4,5 The low expression level, complex interactome and large size of Oroxin B the 348 kDa Huntingtin protein have given rise to technical challenges which have hindered precise determination of its molecular function, or how this is altered in disease. In particular, the use of different Huntingtin antibodies by scientists in the HD research community, often mapping to structurally distant epitopes, Oroxin B can yield different or even conflicting results, further conflating interrogation of this protein.68 This research is a part of a broader collaborative initiative in which academics, funders and commercial antibody manufacturers are working together to address antibody reproducibility issues by characterizing commercial antibodies for human proteins using standardized protocols, and openly sharing the data.911Here we evaluated the performance of twenty commercial antibodies for Huntingtin for use in western blot, immunoprecipitation, and immunofluorescence, enabling biochemical and cellular assessment of Huntingtin properties and function. The platform for antibody characterization used to carry out this study was endorsed by a committee of industry and academic associates. It consists of identifying human cell lines with adequate target protein expression and the development/contribution of comparative knockout (KO) cell lines, followed by antibody characterization procedures using most commercially available antibodies against the corresponding target protein. The standardized consensus antibody characterization protocols are openly available on Protocol Exchange (DOI:10.21203/rs.3.pex-2607/v1).12 The authors do not engage in result analysis or offer explicit antibody recommendations. A limitation of this study is the use of universal protocols – any conclusions remain relevant within the confines of the experimental setup and cell collection used in this study. Our primary aim is to deliver top-tier data to the scientific community, grounded in Open Science principles. This empowers experts to interpret the characterization data independently, enabling them to make informed choices regarding the most suitable antibodies for their specific experimental needs. Guidelines on how to interpret antibody characterization data found in this study are featured around the YCharOS gateway.13 == Results and conversation == Our standard protocol involves comparing readouts from WT (wild type) and KO cells.14,15The first step is to identify a cell line(s) that expresses sufficient levels of a given protein to generate a measurable signal. To this end, we examined the DepMap transcriptomics database to identify all cell lines that express the Rabbit Polyclonal to DGKD target at levels greater than 2.5 log2(transcripts per million TPM + 1), which we have found to be a suitable cut-off (Cancer Dependency Map Portal, RRID:SCR_017655). We generated anHTTKO collection in DMS 53 as it expresses the endogenousHTTtranscript at 6.1 log2(TPM+1), which is usually above the average range of cancer cell lines analyzed. A commercial HAP1HTTKO is also available; HAP1 expressesHTTat 3.7 log2(TPM+1) RNA level. A HEK293THTTKO cell collection has Oroxin B been developed and used elsewhere16(Table 1). All three cell collection backgrounds were evaluated by western blot using a high-performing Huntingtin antibody detected inFigure 1. DMS 53 was identified as the most suitable cell collection (Physique 2), which can be explained by its.