JWA, a cytoskeleton associated gene, was primarily found to be regulated by all trans-retinoic acid (ATRA), 13 cis-retinoic acid (13 cis-RA) and 12-tetradecano-ylphorbol-13-acetate (TPA). Our previous data showed that JWA might be involved in both cellular differentiation and apoptosis induced by several chemicals. In this study, we addressed the possible mechanism of JWA in the regulation of cell differentiation and apoptosis in NB4, a human acute promyelocytic leukemia cell line. CD11b/CD33 expression and cell cycle were analyzed for detecting of cell differentiation and apoptosis. Both reverse-transcription polymerase chain reaction (RT-PCR) and Western blot assays were used for understanding the expressions of JWA. The results showed that under the indicated concentrations ATRA (10-6 mol/L) and As2O3 (10-6 mol/L) induced cell differentiation and apoptosis separately; while both 4HPR (10-6mol/L) and TPA (10-7 mol/L) showed dual-directional effects on NB4 cells, they not only trigger cells’
CAO HaixiaXIA WeiSHEN QunLU HuaYE JianLI AipingZOU ChangpingZHOU Jianwei
Our previous studies demonstrated that JWA, a novel retinoic acids responsive and cytoskeleton related gene, is associated with cell differentiation and apoptosis. In the present study, to elucidate if the JWA is a novel kind of microtubule-associated proteins (MAPs) and functionally link to microtubule, we first successfully identified JWA from the physically purified MAPs complex of rat brain tissues. The results of co-immunoprecipitation, gene trans-fection and immunofluorescence microscopy assays from HBE and NIH3T3 cells provide strong evidence for a linkage between JWA and b-tubulin. In general, JWA is stably binding to b-tubulin whenever microtubule is polymerized or not, and it may be critical to the mitosis process. In addi-tion, by use of the antisense oligonucleotides technique, we also showed that JWA is a negative modulator on intracellu-lar amino acids in PC12 cells. Further analysis indicated that JWA selectively regulates both taurine, an inhibitory amino acid, and glutamate, an excitatory amino acid. In conclusion, JWA is not only structurally associated, but also a novel functional MAP.
