Neuronal morphogenesis is regulated by the interplay between cyclin-dependent kinase 5 and the ubiquitin ligase mind bomb 1

• Type of Material: Article
• Authors: Eun-Ah Choe, Emory University; Lujian Liao, Emory University; Jian-Ying Zhou, Emory University; Dongmei Cheng, Emory University; Duc M. Duong, Emory University; Peng Jin, Emory University; Li-Huei Tsai, Massachusetts Institute of Technology; Junmin Peng, Emory University
• Language: English
• Date: 2007-08-29
• Publisher: Lippincott, Williams & Wilkins
• Publication Version: Final Published Version
• Copyright Statement: Copyright © 2007 Society for Neuroscience.
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1523/JNEUROSCI.1408-07.2007
• Title of Journal or Parent Work: Journal of Neuroscience Nursing
• ISSN: 0888-0395
• Volume: 27
• Issue: 35
• Start Page: 9503
• End Page: 9512
• Grant/Funding Information: This work was supported in part by National Institutes of Health Grants DA019937 and AG025688 (J.P.).
• Keywords: Life Sciences & Biomedicine; RAT FOREBRAIN; NEURITE OUTGROWTH; Science & Technology; E3 LIGASE; PROTEINS; Neurosciences & Neurology; mind bomb; Neurosciences; neuronal morphogenesis; YEAST PROTEOME; MASS-SPECTROMETRY; NOTCH; ubiquitin; mass spectrometry; MIND BOMB; proteomics; FAT FACETS; CDK5; LIQUID FACETS
• Research Categories: Biology, Genetics; Biology, Neuroscience

Abstract

Neuronal communication requires the coordinated assembly of polarized structures including axons, dendrites, and synapses. Here, we report the identification of a ubiquitin ligase mind bomb 1 (Mib1) in the postsynaptic density and the characterization of its role in neuronal morphogenesis. Expression of Mib1 inhibits neurite outgrowth in cell culture and its gene deletion enhances synaptic growth at the neuromuscular junction in Drosophila. The analysis of Mib1 interactome by mass spectrometry revealed that Mib1 primarily interacts with membrane trafficking proteins [e.g., EEA1 (early endosomal antigen 1), Rab11-interacting proteins, and SNAP25 (synaptosomal-associated protein of 25 kDa)-like protein] and cell adhesion components (e.g., catenin, coronin, dystrobrevin, and syndecan), consistent with its previously reported function in protein sorting. More interestingly, Mib1 is associated with deubiquitinating enzymes, BRCC36 and the mammalian ortholog of fat facets, and a number of kinases, such as casein kinase II, MARK (microtubule affinity regulating kinase)/PAR1, and cyclin-dependent kinase 5 (CDK5). Further characterization of the Mib1-CDK5 interaction indicated that the N-terminal domain of Mib1 directly binds to the regulatory subunit p35 of the CDK5 complex. In cell culture, Mib1 induces the relocalization of p35/CDK5 without affecting its degradation. Surprisingly, p35/CDK5 downregulates the protein level of Mib1 by its kinase activity, and completely rescues the Mib1-induced inhibitory effect on neurite morphology. p35/CDK5 also genetically interacts with Mib1 in the fly according to the rough-eye phenotype. The data strongly support that the negative interplay between Mib1 and p35/CDK5 may integrate the activities of multiple pathways during neuronal development.