Loss of aPKCλ in differentiated neurons disrupts the polarity complex but does not induce obvious neuronal loss or disorientation in mouse brains

Tomoyuki Yamanaka; Asako Tosaki; Masaru Kurosawa; Kazunori Akimoto; Tomonori Hirose; Shigeo Ohno; Nobutaka Hattori; Nobuyuki Nukina

doi:10.1371/journal.pone.0084036

Loss of aPKCλ in differentiated neurons disrupts the polarity complex but does not induce obvious neuronal loss or disorientation in mouse brains

PLoS One. 2013 Dec 31;8(12):e84036. doi: 10.1371/journal.pone.0084036. eCollection 2013.

Authors

Tomoyuki Yamanaka¹, Asako Tosaki², Masaru Kurosawa¹, Kazunori Akimoto³, Tomonori Hirose⁴, Shigeo Ohno⁴, Nobutaka Hattori⁵, Nobuyuki Nukina⁶

Affiliations

¹ Laboratory for Structural Neuropathology, RIKEN Brain Science Institute, Saitama, Japan ; Department of Neuroscience for Neurodegenerative Disorders, Juntendo University Graduate School of Medicine, Tokyo, Japan.
² Laboratory for Structural Neuropathology, RIKEN Brain Science Institute, Saitama, Japan.
³ Department of Molecular Medical Science, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Chiba, Japan.
⁴ Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Yokohama, Japan.
⁵ Department of Neurology, Juntendo University Graduate School of Medicine, Tokyo, Japan.
⁶ Laboratory for Structural Neuropathology, RIKEN Brain Science Institute, Saitama, Japan ; Department of Neuroscience for Neurodegenerative Disorders, Juntendo University Graduate School of Medicine, Tokyo, Japan ; Core Research for Evolutionary Science and Technology, Japan Science and Technology Agency, Tokyo, Japan.

Abstract

Cell polarity plays a critical role in neuronal differentiation during development of the central nervous system (CNS). Recent studies have established the significance of atypical protein kinase C (aPKC) and its interacting partners, which include PAR-3, PAR-6 and Lgl, in regulating cell polarization during neuronal differentiation. However, their roles in neuronal maintenance after CNS development remain unclear. Here we performed conditional deletion of aPKCλ, a major aPKC isoform in the brain, in differentiated neurons of mice by camk2a-cre or synapsinI-cre mediated gene targeting. We found significant reduction of aPKCλ and total aPKCs in the adult mouse brains. The aPKCλ deletion also reduced PAR-6β, possibly by its destabilization, whereas expression of other related proteins such as PAR-3 and Lgl-1 was unaffected. Biochemical analyses suggested that a significant fraction of aPKCλ formed a protein complex with PAR-6β and Lgl-1 in the brain lysates, which was disrupted by the aPKCλ deletion. Notably, the aPKCλ deletion mice did not show apparent cell loss/degeneration in the brain. In addition, neuronal orientation/distribution seemed to be unaffected. Thus, despite the polarity complex disruption, neuronal deletion of aPKCλ does not induce obvious cell loss or disorientation in mouse brains after cell differentiation.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adaptor Proteins, Signal Transducing / genetics
Adaptor Proteins, Signal Transducing / metabolism
Animals
Blotting, Western
Brain / metabolism
Brain / pathology*
Cell Adhesion Molecules / genetics
Cell Adhesion Molecules / metabolism
Cell Cycle Proteins
Cell Differentiation*
Cell Polarity*
Female
Glycoproteins / genetics
Glycoproteins / metabolism
Immunoenzyme Techniques
Immunoprecipitation
Integrases / metabolism
Isoenzymes / physiology*
Male
Mice
Mice, Inbred C57BL
Mice, Knockout
Neurogenesis / physiology*
Neurons / metabolism
Neurons / pathology*
Protein Kinase C / physiology*
RNA, Messenger / genetics
Real-Time Polymerase Chain Reaction
Reverse Transcriptase Polymerase Chain Reaction

Substances

Adaptor Proteins, Signal Transducing
Cell Adhesion Molecules
Cell Cycle Proteins
Glycoproteins
Isoenzymes
LGL1 protein, mouse
Par6 protein, mouse
Pard3 protein, mouse
RNA, Messenger
Protein Kinase C
protein kinase C lambda
Cre recombinase
Integrases

Grants and funding

This work was supported by a Grant-in-Aid from Ministry of Education, Culture, Sports, Science and Technology of Japan for TY (24111553, 23700430) and NN (22110004, 22240037, 24659436) (http://www.mext.go.jp/), by Special Postdoctoral Researchers Program of RIKEN for TY. (http://www.riken.go.jp/en/careers/programs/spdr/), by Core Research for Evolutionary Science and Technology from Japan Science and Technology Agency for NN. (http://www.jst.go.jp/kisoken/crest/); and by Grant-in-Aid for the Research on Measures for Ataxic Diseases from the Ministry of Health, Welfare and Labor for NN (http://ataxia.umin.jp/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.