[Frontiers in Bioscience E3, 1241-1248, June 1, 2011]

Involvement of LOC66273 isoform 2, a novel Mth938 containing protein, in MAPK pathway

Hualang Wang1, Xi Ma1, Heyu Zhang2, Jianjun Zang1, Shengdi Hu1, Defa Li1

1State Key Laboratory of Animal Nutrition, China Agricultural University, No. 2 Yuanmingyuan West Road, Beijing 100193, China. 2 Human Disease Genomics Center, Peking University, No. 38 Xueyuan Road, Beijing 100191, China


1. Abstract
2. Introduction
3. Materials and Methods
3.1. Reagents
3.2. cDNA cloning and vector construction
3.3. Polyclonal anti-LI2 antibody preparation
3.4. Cell line and transfection
3.5. RNA Isolation and reverse transcription-PCR analysis
3.6. Fluorescence microscopy
3.7. Protein extraction and Immunoblot analysis
3.8. Dual-luciferase reporter assay
4. Results
4.1. Cloning and bioinformatics analysis of mouse LI2
4.2. Expression profiles
4.3. Sub-cellular localization of LI2 protein
4.4. Over-expression of LI2 promoted AP-1 activity
4.5. Over-expression of LI2 increased Elk1 and c-jun transcriptional activity, but not c-fos
4.6. LI2 promoted phosphorylation of ERK1/2 and SAPK/JNK, but not p38
5. Discussion
6. Acknowledgment
7. Reference


Using dual-luciferase reporter assay system, our previous study showed that LI2, significantly increased AP-1 transcriptional activity. Sub-cellular localization showed that GFP-LI2 fusion protein is diffusely distributed in the cytoplasm, with some highly concentrated spots around the nucleus, suggesting that LI2 protein has a physiological role in cytoplasm. Overexpression of LI2 significantly increased AP-1 transcriptional activity. Moreover, LI2 significantly promoted transcriptional activity of Elk1 and c-jun, which might, at least partly, be associated with activated ERK1/2 and JNK/SAPK signaling pathway. These data suggest that LI2 is a novel MAPK regulating protein.