Protein kinase A (PKA) plays critical roles in neuronal function that are mediated by different regulatory (R) subunits. Deficiency in either RIÎ² or RIIÎ² subunits results in distinct neuronal phenotypes. Although RIÎ² contributes to synaptic plasticity, it is the least studied isoform. Using isoform-specific antibodies we generated high-resolution large-scale immunohistochemical mosaic images of mouse brain that provide global views of several brain regions, including the hippocampus and cerebellum. The isoforms concentrate in discrete brain regions and we then zoom-in to show distinct patterns of subcellular localization. RIÎ² is enriched in dendrites and co-localizes with MAP2, whereas RIIÎ² is concentrated in axons. Using correlated light and electron microscopy we confirm mitochondrial and nuclear localization of RIÎ² in cultured neurons. To show the functional significance of nuclear localization, we demonstrate that down-regulation of RIÎ², but not RIIÎ², decreased CREB phosphorylation. Our study reveals how PKA isoform specificity is defined by precise localization.
- Susan S Taylor
- Mark H Ellisman
- Mark H Ellisman
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Animal experimentation: All experiments involving vertebrate animals conform to the National Institute of Health Guide for the Care and Use of Laboratory Animals (NIH publication 865-23, Bethesda, MD, USA) and were approved by the Institutional Animal Care and Use Committee (IACUC) of the University of California San Diego. Approved Animal Protocol Numbers: S03172m, S03182R.
- Mary B Kennedy, California Institute of Technology, United States
© 2017, Ilouz et al.
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