Molecular cloning and characterization of Bif-1 - A novel Src homology 3 domain-containing protein that associates with Bax
Molecular cloning and characterization of Bif-1 - A novel Src homology 3 domain-containing protein that associates with Bax
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DOI：
10.1074/jbc.m101527200
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发表时间：
2001-06-08
影响因子：
4.8
通讯作者：
Wang, HG
中科院分区：
文献类型：
--
作者：
Cuddeback, SM;Yamaguchi, H;Wang, HG
Bax是Bcl-2蛋白家族的促凋亡成员，其使细胞响应于凋亡刺激而经历程序性细胞死亡。为了进一步了解Bax的机制，我们已经确定了一种新的Bax结合蛋白，称为Bif-1，通过使用酵母双杂交克隆技术。Bif-1是一种进化上保守的胞质蛋白，其含有位于其C末端附近的预测Src同源3（SH 3）结构域，但与Bcl-2家族成员没有显著的同源性。北方印迹分析表明Bif-1在大多数组织中表达，在心脏和骨骼肌中表达丰富。Bif-1能够与Bax相互作用，如酵母双杂交、免疫共沉淀和免疫荧光研究所示。通过白细胞介素-3戒断诱导小鼠前B造血细胞FL5.12凋亡导致Bax与Bif-1的关联增加，这伴随着Bax蛋白的构象变化。Bif-1过表达促进IL-3剥夺后FL5.12细胞中Bax构象变化、caspase激活和凋亡性细胞死亡。因此，BIF-1代表了一种新型的细胞凋亡信号通路调节因子。
Bax is a proapoptotic member of the Bcl-2 protein family that commits the cell to undergo programmed cell death in response to apoptotic stimuli. To gain further insights into Bax mechanisms, we have identified a novel Bax-binding protein, termed Bif-1, by using a yeast two-hybrid cloning technique. Bif-1 is an evolutionarily conserved cytoplasmic protein that contains a predicted Src homology 3 (SH3) domain located near its C terminus but shares no significant homology with members of the Bcl-2 family. A Northern blot analysis indicates that Bif-1 is expressed in most tissues with abundant expression in heart and skeletal muscle. Bif-1 is capable of interacting with Bax as demonstrated by yeast two-hybrid, coimmunoprecipitation, and immunofluorescence studies. Induction of apoptosis in murine pre-B hematopoietic cells FL5.12 by interleukin-3 withdrawal results in increased association of Bax with Bif-1, which is accompanied by a conformational change in the Bax protein. Overexpression of Bif-1 promotes Bax conformational change, caspase activation, and apoptotic cell death in FL5.12 cells following interleukin-3 deprivation. Bif-1 thus represents a new type of regulator of Bax-mediated signaling pathways for apoptosis.