Calcium often serves as a link connecting neural activity to gene transcription. Kashani et al. used a transactivator trap screen to identify mediators of calcium-dependent gene transcription, a method that previously led them to identify CREST, a calcium-regulated transcriptional activator. The authors screened pools of rat cortical cDNA library by transfection into cortical neurons and then looked for activation of a reporter gene after depolarization and calcium influx. Here they report on LMO4, a 165 aa nuclear LIM-domain-only protein that is expressed in cortex during the early postnatal period. LMO4 activation required L-type voltage-gated channels and NMDA receptors, as well as activation of calcium/calmodulin-dependent kinase IV and mitogen-activated protein kinase. LMO4 interacted with CREB (cAMP response element-binding protein) and the coactivators CLIM1 and CLIM2. Conditional deletion of lmo4 in the forebrain disrupted segregation of thalamocortical afferents into barrel domains in the somatosensory cortex.

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Amir H. Kashani, Zilong Qiu, Linda Jurata, Soo-Kyung Lee, Samuel Pfaff, Sandra Goebbels, Klaus-Armin Nave, and Anirvan Ghosh

Source: News tips from the Journal of Neuroscience

Contact: Sara Harris
Society for Neuroscience