简介:囊包含域的蛋白质属于phosphoinositide磷酸酶(PIPPase家庭)的一个最新识别的家庭。尽管有描绘得好的酶的活动,这个哺乳动物的囊领域PIPPase家庭的生物功能仍然保持大部分未知。我们识别了新奇的囊包含域的蛋白质,老鼠Sac3(rSac3)它是广泛地在各种各样的纸巾表示了并且对endoplasmic蜂窝胃局部性,Golgi复杂、再循环的内涵体。rSac3在vitro作为底层与PI(3)P,PI(4)P和PI(3,5)P(2)显示PIPPase活动,并且在囊域的催化核心的一个变化废除它的酶的活动。rSac3的表示起来在刺激的神经生长因素(NGF)期间调整了PC12细胞neuronal区别,并且在这的表示上,蛋白质在PC12细胞支持神经突长出。相反地,由反感觉oligonucleotides的rSac3表示的抑制减少刺激NGF的PC12房间的神经突长出,并且rSac3的活跃地点变化消除它的neurite-outgrowth-promoting活动。这些结果显示rSac3在通过它的PIPPase活动区分神经原支持神经突长出,建议囊领域PIPPase蛋白质可以参予从到血浆膜的endoplasmic蜂窝胃和Golgi建筑群的前面的膜交通国王,并且可以作为neuronal房间生长和区别的这个关键过程的管理者工作。
简介:<正>WeandothershavefirmlyestablishedthatsurfaceIgMreceptor(sIgM-R)crosslinkingwithantibodiestotheiheavychain(anti-i)leadstogrowtharrestandapoptosisinaseriesofwellcharacterizedB-celllymphomas.Thisrequiresablationofc-Mycproteinexpressionandtheconcomitantinductionofthecyclin-dependent-kinaseinhibitor,p27Kip1.Thesignalingmechanismsregulatingc-Mycandp27Kip1proteinexpressionarepoorlyunderstood.However,werecentlyestablishedthatsIgM-Rmediateddown-modulationofthePI-3Kpathwaydirectlyaffectedc-Mycandp27Kip1expressionandaccuratelypredictedgrowtharrest
简介:cAMPmediatedsignalingmayplayasuppressiveroleinimmuneresponse.WepreviouslyfoundthatthecAMP-elevators(CTxand8-Br-cAMP)inhibitedIL-12,IL-la,IL-6geneexpression,butincreasedthetranscriptionallevelsofIL-10andIL-1RainLPS-treatedmurineperitonealmacrophages.ThepresentstudyexaminedapossiblemolecularmechanisminvolvedincAMPelevators-inducedinhibitionofIL-12p40expressioninresponsetoLPS.OurdatademonstratedthatcAMPelevatorsdownregulatedIL-12p40mRNAexpressionandIL-12pT0productioninmurineperitonealmacrophages.SubsequentstudiesrevealedthatcAMP-elevatorsblockedphosphorylationofp38MAPK,butdidnotaffecttheactivityofNF-κBbindingtoIL-12promoter(-136/-112).ThisisthefirstreportthatcAMPelevatorsinhibitLPS-inducedIL-12productionbyamechanismthatisassociated,atleastinpart,withp38-dependentinhibitionbycAMPsignalingpathways.