2012 Fiscal Year Final Research Report

Spinal cord injury (SCI)-mediated expression of protein arginine N-methyltransferase 8 (PRMT8)expression in activated microglia/macrophage

Research Project

Project/Area Number	23650183
Research Category	Grant-in-Aid for Challenging Exploratory Research
Allocation Type	Multi-year Fund
Research Field	Nerve anatomy/Neuropathology
Research Institution	Osaka University
Principal Investigator	MORI Yasutake 大阪大学, 医学系研究科, 准教授 (00343252)
Project Period (FY)	2011 – 2012
Keywords	タンパク質メチル化
Research Abstract	Protein arginine N-methyltransferase 8 (PRMT8) was originally reported as a neuron-specific type II PRMT with dominantly nuclear distribution. However, when we examined changes in PRMT8 expression level in the spinal cords injured by hemisection, unambiguous signals were observed in the cytoplasm of round-shaped cells that were densely packed around the lesion site. This group of cells were well-overlapped with CD11b-positive cells, not with neurons, demonstrating that PRMT8 is expressed in the activated microglia/macrophage cells. By Western blot analysis, PRMT8 from the injured spinal cord showed a slower mobility shift band with Mw of 60-62kDa than that from brain lysate with Mw of 42kDa. We demonstrated that the high molecular weight (HMW) PRMT8is due to phosphorylation and the myristoylation might be caused by an additional N-terminal stretch harboring consensus myristoylation site that would stem from usage of another in-frame translation initiation site. These data raise the possibility that membranebound type of PRMT8 can be a novel marker for activated microglia.