Potential target proteins binding to VirB4 of type Ⅳ secretion system were screened during Brucella infected bovine embryonic trophoblast cells .Brucella VirB4 genes were amplified by PCR with species-specific primers .Expression vector pGBKT7-virB4 was constructed and analysed by sequencing and restriction enzymes ,transforming to the yeast strain Y187 and testing self-activation and toxicity .The cells model and cDNA library of bovine embryonic trophoblast cells infected with Brucella abortus strain were constructed respectively .Utilizing yeast two-hybrid system was employed to screen the target proteins of bovine embryo trophoblastic cells which was conjunctive with virB4 .These proteins were detected by real-time fluo-rescence quantitative PCR .The results suggested that bait plasmid pGBKT7-virB4 was successfully transformed into the Y187 and there was no toxicity and self-activation;the cDNA library of bovine embryonic trophoblast cells infected with Brucella abortus strain was constructed .There screened 13 positive plasmids in which Q10 and SLC3A2 were up-regulated at the mRNA level .In this paper ,we reported the interactions between the VirB4 protein of Brucella and the bovine embryo trophoblastic cells ,which provide an upstream work for further elucidating the pathogenesis of Brucella infection of the host cell .

Objective To investigate the molecular mechanism of translocation of heterogeneous nuclear ribonucleoprotein A2B1 (hnRNPA2B1 )to the cytoplasm after glucose starvation and the effects of increased cytoplasmic translocation of hnRNPA2B1 on the survival of prostate cancer PC3 cells. Methods Human prostate cancer PC3 cells were divided into normal control group (cultured conventionally with glucose-containing medium,RPMI 1640 Medium)and glucose starvation group (cultured with glucose-free medium,RPMI 1640 Medium).The 2 types of cells were treated with deacetylase inhibitor,trichostatin A (TSA ) combined with nicotinamide (NAM),AKT inhibitor BEZ235,si-NC transfection,and si-hnRNPA2B1 transfection,respectively.Cytoplasmic and nuclear protein separation,immunoprecipitation and Western blotting were used to detect changes in hnRNPA2B1 acetylation,total AKT protein and its phosphorylation level,and expression levels of hnRNPA2B1 in the cytoplasm and nucleus.CCK-8 assay was employed to observe cell survival in each group.Results After 3～5 h of glucose starvation treatment,the acetylation of hnRNPA2B1 protein was reduced (P<0.01 ),and its cytoplasmic translocation was increased in PC3 cells (P<0.01 ),which was accompanied by enhanced AKT phosphorylation and activation of the AKT signaling pathway.TSA/NAM treatment,BEZ235 treatment,and si-hnRNPA2B1 transfection all resulted in obvious increase in acetylation of hnRNPA2B1 protein when compared with glucose starvation treated cells (P<0.01 ),which could inhibit the glucose starvation-mediated cytoplasmic translocation of hnRNPA2B1,suppress AKT phosphorylation,and consequently decrease the cell survival rate after glucose starvation (P<0.01).Conclusion Glucose starvation can maintain the survival of PC3 cells by inducing the activation of the Ac-hnRNPA2B1-AKT signaling pathway.