TY - JOUR T1 - A metabolic CRISPR-Cas9 screen in Chinese hamster ovary cells identifies glutamine-sensitive genes JF - bioRxiv DO - 10.1101/2020.05.07.081604 SP - 2020.05.07.081604 AU - Karen Julie la Cour Karottki AU - Hooman Hefzi AU - Songyuan Li AU - Lasse Ebdrup Pedersen AU - Philipp Spahn AU - Chintan Joshi AU - David Ruckerbauer AU - Juan Hernandez Bort AU - Alex Thomas AU - Jae Seong Lee AU - Nicole Borth AU - Gyun Min Lee AU - Helene Faustrup Kildegaard AU - Nathan E. Lewis Y1 - 2021/01/01 UR - http://biorxiv.org/content/early/2021/02/02/2020.05.07.081604.abstract N2 - Over the past decades, optimization of media formulation and feeding strategies have fueled a many-fold improvement in CHO-based biopharmaceutical production. While Design of Experiments (DOE) and media screens have led to many advances, genome editing offers another avenue for enhancing cell metabolism and bioproduction. However the complexity of metabolism, involving thousands of genes, makes it unclear which engineering strategies will result in desired traits. Here we developed a comprehensive pooled CRISPR screen for CHO cell metabolism, including ∼16,000 gRNAs against ∼2500 metabolic enzymes and regulators. We demonstrated the value of this screen by identifying a glutamine response network in CHO cells. Glutamine is particularly important since it is often substantially over-fed to drive increased TCA cycle flux but can lead to accumulation of toxic ammonia. Within the glutamine-response network, the deletion of a novel and poorly characterized lipase, Abhd11, was found to substantially increase growth in glutamine-free media by altering the regulation of the TCA cycle. Thus, the screen provides an invaluable targeted platform to comprehensively study genes involved in any metabolic trait.Competing Interest StatementThe authors have declared no competing interest.αkgdhcalpha ketoglutarate dehydrogenase complexCas9CRISPR-associated protein 9CHOChinese hamster ovaryCPMcounts per millionCRISPRclustered regularly interspaced short palindromic repeatsDAPI4’,6-diamidino-2-phenylindoleGFPgreen fluorescent proteinGLSglutaminaseGLULglutamine synthetasegRNAguide RNAMgat1mannosyl (alpha-1,3-)- glycoprotein beta-1,2-N-acetylglucosaminyltransferaseNGSnext generation sequencingRNAiRNA interferenceTALENtranscription activator-like effector nucleasesVCDviable cell densityZFNzinc-finger nuclease ER -