TY - JOUR T1 - Cell-type selective deletion of RSK2 reveals insights into altered signaling in Coffin-Lowry Syndrome JF - bioRxiv DO - 10.1101/156257 SP - 156257 AU - Hu Zhu AU - Ryan T. Strachan AU - Daniel J. Urban AU - Martilias S. Farrell AU - Wesley K. Kroeze AU - Justin G. English AU - Reid H.J. Olsen AU - Bryan L. Roth Y1 - 2017/01/01 UR - http://biorxiv.org/content/early/2017/06/26/156257.abstract N2 - Coffin-Lowry syndrome (CLS) is an X-linked syndromic form of mental retardation characterized by various skeletal dysmorphisms, moderate to severe mental retardation, and in some cases, psychosis. CLS is caused by loss-of-function mutations of the p90 ribosomal S6 kinase 2 (RPS6KA3) gene encoding a growth factor-regulated serine/threonine kinase, ribosomal S6 kinase 2 (RSK2). We previously identified RSK2 as a novel interacting protein that tonically inhibits 5-HT2A receptor signaling by phosphorylating Ser-314 within the third intracellular loop. To determine if RSK2 inhibits 5-HT2A receptor signaling in vivo and whether disruption of RSK2 could lead to schizophrenia-like behaviors - as is seen in some CLS patients - we genetically disrupted the function of RSK2 either globally or selectively in forebrain pyramidal neurons in mice. Both global and forebrain-selective RSK2 deletion augmented the locomotor responses to the psychotomimetic drugs phencyclidine (PCP) and amphetamine (AMPH). Significantly, forebrain-selective deletion of RSK2 augmented 5-HT2A receptor signaling as exemplified by enhanced 5-HT2A-mediated c-fos activation and head-twitch response without altering the levels or distribution of 5-HT2A receptor protein. Thus, RSK2 modulates 5HT2A receptor function in vivo, and disruption of RSK2 leads to augmented psychostimulant-induced responses reminiscent of those seen in many animal models of schizophrenia. These findings strengthen the association between 5-HT2A receptor dysfunction and psychosis, and provide a potential mechanism underlying the schizophrenia-like symptoms present in some CLS patients.Global and cell-type-specific RSK2 knock-out mice were assessed behaviorally and pharmacologicallyAugmentation of amphetamine and PCP locomotor responses were seen in both global and forebrain-specific RSK2 KO miceAugmentation of 5-HT2A serotonin receptor function but not number was also observedThese alterations reveal insights into mechanisms potentially responsible for behavioral sequlae of Coffin-Lowry Syndrome ER -