Oligomerization study of NHR3 and NHR4 domains from ETO protein involved in t(8;21)-associated acute myeloid leukemia  

作　　者：WUDonghui YANGHaitao XUEXiaoyu LIANGWenxue MIAOXiaoyu CHENSaijuan PANGHai 

机构地区：[1]ShanghaiInstituteofHematology,Rui-jinHopitalaffiliatedtoShanghaiSecondMedicalUniversity//ShanghaiFirstPeople'sHospitalaffiliatedtoShanghaiJiaotongUniversity [2]LaboratoryofStructuralBiology,DepartmentofBiologicalSciencesandBiotechnology&ProteinSciencesLaboratoryofMOE,TsinghuaUniversity,Beijing100084,China [3]ShanghaiInstituteofHematology,StateKeyLaboratoryofMedicalGenomics,Rui-jinHopitalaffiliatedtoShanghaiSecondMedicalUniversity,Shanghai200025,China

出　　处：《Chinese Science Bulletin》2005年第9期875-879,共5页

基　　金：This work was supported by the National Natural Science Foundation of China(Grant No.30370300).

摘　　要：Little had been known about ETO protein until t(8;21) was found in 12%―15% of acute myeloid leukemia which resulted in AML1-ETO fusion protein. ETO protein has four conserved nervy homology regions termed NHR1― 4. A lot have already been known about NHR1, 2, 4: NHR1 is homologous with the Drosophila TATA-box-associated factor 110 (TAF110); NHR2 is a dimerization domain associated with mSin3A/HDAC; NHR4 is MYND class of zinc fingers associated with NCoR/SMRT/HDAC. Only the function of NHR3 remains unclear. In order to investigate whether NHR3 domain could participate in oligomerization, we cloned and purified this domain. Through gel filtration chromatography, dynamic light scattering and dissolved crystal electrophoresis, we found that NHR3 domain was a tight tetramer. Then we cloned NHR3+4 domain (i.e. NHR3 domain plus NHR4 domain), and discovered, by gel filtration chromatography and native PAGE, that NHR3+4 domain could form dimer in solution. This was the first time to ob- serve that NHR3 and NHR4 domains may have some con- tribution to the oligomerization of ETO protein, which might recruit corepressors in the form of dimer, and stabilize ETO dimerization through convergent strength of NHR2, NHR3 and NHR4 domains and then stabilize corepressors recruit- ment. These speculations are very worthy of further evalua- tion.Little had been known about ETO protein until t(8;21) was found in 12percent-15 percent of acute myeloid leukemia which resulted in AML1-ETG fusion protein. ETO proteinhas four conserved nervy homology regions termed NHR1 - 4. A lot have already been known aboutNHR1,2,4: NHR1 is homologous with the Drosophila TATA-box-associated factor 110 (TAF110); NHR2 is adimerization domain associated with mSin3A/HDAC; NHR4 is MYND class of zinc fingers associated withNCoR/SMRT/HDAC. Only the function of NHR3 remains unclear. In order to- investigate whether NHR3domain could participate in oligomerization, we cloned and purified this domain. Through gelfiltration chromatography, dynamic light scattering and dissolved crystal electrophoresis, we foundthat NHR3 domain was a tight tetramer. Then we cloned NHM3+4 domain (i.e. NHR3 domain plus NHR4domain), and discovered, by gel filtration chromatography and native PAGE, that NHR3+4 domain couldform dimer in solution. This was the first time to observe that NHR3 and NHR4 domains may have somecontribution to the oligomerization of ETO protein, which might recruit corepressors in the form ofdimer, and stabilize ETO dimerization through convergent strength of NHR2, NHR3 and NHR4 domains andthen stabilize corepressors recruitment. These speculations are very worthy of further evaluation.

关 键 词：白血病 NHR3 NHR4 发病机理 治疗方法 蛋白质 

分 类 号：R733.7[医药卫生—肿瘤]