GEOapplication/xmlftp://ftp.ncbi.nlm.nih.gov/geo/series/GSE326nnn/GSE326336/primaryOK200TranscriptomicsMus musculusExpression profiling by high throughput sequencinghttps://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE326336GEOGSEfalseCRISPR/Cas9 screening reveals key role of STK11/LKB1 in vasopressin-mediated regulation of Aqp2 transcriptionIdentification of signaling networks is an essential goal in systems biology. Here, we use CRISPR knockout screening (employing a whole kinome sgRNA library) to identify functionally critical protein kinases in a well-studied Gs-dependent G-protein coupled receptor (GPCR)-signaling model, namely the vasopressin V2 receptor (V2R). Screening was done using a specially-designed fluorescence-based reporter cell line with green-fluorescent protein (GFP) co-transcribed with Aqp2, a gene whose transcription is dependent on vasopressin-mediated activation of protein kinase A (PKA). The reporter line endogenously expresses V2R. Positive regulators (n=16) included PKA-catalytic subunit α (but not β). Mark2 (Par1b) and Dyrk1a (minibrain homolog). Negative regulators (n=13) included PKA-regulatory subunit type Iα, Stk11 (liver kinase B1 [LKB1]), and three TGF-β receptor subunits (Tgfbr1, Tgfbr2, Tgfbr3) (see https://esbl.nhlbi.nih.gov/Databases/Kinome-CRISPR-screen/ for full list). Dyrk1a and Stk11/LKB1 knockout cell lines were created for further study. Dyrk1a knockout cell lines failed to express AQP2 protein and exhibited a profound decrease in AQP2 mRNA. RNA-sequencing demonstrated widespread increases in cell-cycle transcripts, with a general defect in cell differentiation, accounting for AQP2 loss. Stk11/LKB1 knockout lines displayed marked increases in AQP2 protein and mRNA. RNA-sequencing and phospho-proteomic findings point to a signaling model in which Stk11/LKB1- and PKA-mediated phosphorylation events exert counteracting effects on the activities of cAMP-responsive transcriptional coactivator (CRTC) proteins. Finally, additional studies confirmed that TGF-β exposure to un-transformed cells results in a profound decrease in AQP2 mRNA abundance along with most recognized differentiation markers, consistent with our prior conclusion that TGF-β represses Aqp2 gene expression by inducing epithelial-mesenchymal transition.2026/03/30GSE326336GSM9629585GSM9629584GSM9629587GSM9629586GSM9629581GSM9629580GSM9629583GSM9629582GSM9629608GSM9629607GSM9629609GSM9629604GSM9629603GSM9629606GSM9629605GSM9629600GSM9629589GSM9629588GSM9629602GSM9629569GSM9629601GSM9629596GSM9629574GSM9629573GSM9629595GSM9629576GSM9629598GSM9629597GSM9629575GSM9629570GSM9629592GSM9629591GSM9629594GSM9629572GSM9629593GSM9629571GSM9629590GSM9629611GSM9629578GSM9629610GSM9629599GSM9629577GSM9629579GSM962961234328326336Mus musculus