Cdk5-mediated phosphorylation of CRMP-2 enhances its interaction with CaV2.2
FEBS LETTERS
Authors: Brittain, Joel M.; Wang, Yuying; Eruvwetere, Omotore; Khanna, Rajesh
Abstract
The axon/dendrite specification collapsin response mediator protein-2 (CRMP-2) bidirectionally regulates N-type voltage-gated Ca2+ channels (CaV2.2). But how cyclin dependent kinase 5 (Cdk5)-mediated phosphorylation of CRMP-2 affects its interaction/regulation with CaV2.2 is unknown. CRMP-2-mediated enhancement of currents via CaV2.2 was not observed with a Cdk5 phospho-null CRMP-2-S522A mutant or in cells expressing an inactive Cdk5. Concomitant knockdown of endogenous CRMP2 and overexpression of CRMP2-S522A mutant refractory to knockdown phenocopied the reduction in Ca2+ influx while the Rho kinase CRMP2-T555A mutant was ineffective. Cdk5-phosphorylated CRMP-2 had increased association with CaV2.2. These results identify an important role for Cdk5 in CRMP2-mediated CaV2.2 regulation. Structured summary of protein interactions: Gsk3b phosphorylates Crmp2by phosphatase assay (View interaction) Crmp2 physically interacts with Cav2.2 by anti tag coimmunoprecipitation (View interaction) (C) 2012 Federation of European Biochemical Societies. Published by Elsevier B. V. All rights reserved.
Genetic dissection of the neuro-glio-vascular machinery in the adult brain
MOLECULAR BRAIN
Authors: Kirschen, Gregory W.; Kery, Rachel; Liu, Hanxiao; Ahamad, Afrinash; Chen, Liang; Akmentin, Wendy; Kumar, Ramya; Levine, Joel; Xiong, Qiaojie; Ge, Shaoyu
Abstract
The adult brain actively controls its metabolic homeostasis via the circulatory system at the blood brain barrier interface. The mechanisms underlying the functional coupling from neuron to vessel remain poorly understood. Here, we established a novel method to genetically isolate the individual components of this coupling machinery using a combination of viral vectors. We first discovered a surprising non-uniformity of the glio-vascular structure in different brain regions. We carried out a viral injection screen and found that intravenous Canine Adenovirus 2 (CAV2) preferentially targeted perivascular astrocytes throughout the adult brain, with sparing of the hippocampal hilus from infection. Using this new intravenous method to target astrocytes, we selectively ablated these cells and observed severe defects in hippocampus-dependent contextual memory and the metabolically regulated process of hippocampal neurogenesis. Combined with AAV9 targeting of neurons and endothelial cells, all components of the neuro-glio-vascular machinery can be simultaneously labeled for genetic manipulation. Together, we demonstrate a novel method, which we term CATNAP (CAV/AAV Targeting of Neurons and Astrocytes Perivascularly), to target and manipulate the neuro-glio-vascular machinery in the adult brain.