Screening of substrates of protein arginine methyltransferase 1 in glioma.
OBJECTIVE
To screen the asymmetric dimethyl arginines (ADMA)-containing proteins which could combine with protein arginine methyltransferase 1 (PRMT1).


METHODS
Western blot was adopted to identify the expression of PRMT1 and the proteins with ADMA in glioma cell lines and normal brain tissues, and then to detect the changes of ADMA level after knock-down of PRMT1 with RNAi transfection in U87MG cells. Co-Immunoprecipitation (Co-IP), western blot, and sliver staining were employed to screen the candidate binding proteins of PRMT1. Then liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to identify the binding proteins of PRMT1.


RESULTS
The expression of PRMT1 and some levels of ADMA were higher in glioma cell lines than in normal brain tissues. After knocking down PRMT1, some ADMA levels were found declined. After screening the binding proteins of PRMT1 with Co-IP and LC-MS/MS, 26 candidate binding proteins were identified. Among them, 6 candidate proteins had higher ions scores (> 38) and bioinformation analysis predicted that SEC23-IP, ANKHD1-EIF4EBP3 protein, and 1-phosphatidylinositol-3-phosphate 5-kinase isoform 2 had possible methylated aginine sites.


CONCLUSIONS
The high expression of PRMT1 in glioma may induce the change of ADMA levels. Altogether 26 candidate proteins were identified, which contain ADMA and specifically bind with PRMT1.
National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100005, China.
Shan
S
Wang
Xiao-Chao
XC
Tan
Bin
B
Yang
Bin
B
Yin
Xiao-Zhong
XZ
Peng
D001120:Arginine / Q000031:analogs & derivatives* / Q000032:analysis; D045744:Cell Line, Tumor; D002853:Chromatography, Liquid; D005910:Glioma / Q000737:chemistry*; D006801:Humans; D047468:Immunoprecipitation; D011484:Protein-Arginine N-Methyltransferases / Q000032:analysis* / Q000502:physiology; D012097:Repressor Proteins / Q000032:analysis* / Q000502:physiology; D013379:Substrate Specificity; D053719:Tandem Mass Spectrometry
D012097:Repressor Proteins; C018524:N,N-dimethylarginine; D001120:Arginine; C099988:PRMT1 protein, human; D011484:Protein-Arginine N-Methyltransferases