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.

[Screening and identification of natural antisense transcript in mouse cerebral cortex].

OBJECTIVE: To screen and identify the possible existence of natural antisense transcript (NAT) within the mouse neocortex. METHODS: Sixty-three cerebral cortex layer-specific genes were screened by bioinformatics prediction in mice, among which 31 mice with potential NATs were screened. NAT was identified using reverse transcription polymerase chain reaction (RT-PCR) and then cloned in pGEM-T Vector System for sequencing. RESULTS: Among 31 genes predicted using bioinformatics, 8 were proved to be NAT positive by RT-PCR. CONCLUSIONS: NATs exist in the mouse neocortex tissue during the development of cerebral cortex. NATs may influence mouse cortical development by regulating the related coding genes.