Overexpression of BimSs3, the novel isoform of Bim, can trigger cell apoptosis by inducing cytochrome c release from mitochondria.
Bim is defined as the pro-apoptotic BH3-only protein of the Bcl-2 family, which is a critical sensor and mediator in the mitochondrial-dependent apoptosis. In a previous work, we have cloned a novel transcript of Bim (GenBank accession number: AY305716) from the fetal brain cDNA, which is widely expressed in some carcinoma tissues and normal human tissues. According to the sequence analysis and the newly-defined nomenclature system of Bim isoforms (Adachi et al., 2005, Cell Death Differ 2: 192), we term it BimSs3 according to its characteristic structure. The subcellular location analysis indicated that the fused protein GFP-BimSs3 is distributed in the whole cell, mainly to the nucleus. Overexpression of BimSs3 in HEK293 cells causes apoptosis (28.16 +/- 1.55%) compared to the negative control (5.44 +/- 2.63%). It also causes cytochrome c release from the mitochondrial fraction to the cytosolic fraction during apoptosis. Western blotting assay indicates the molecular mass of GFP-BimSs3 is approximately 31.0 kDa (GFP: 27 kDa). Hence the open reading frame of BimSs3 may initiate at the second ATG and encodes a 36 amino-acid peptide with BH3 domain.
Liu
Lingfeng
L
State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai, P.R. China.
Chen
Jinzhong
J
Zhang
Jiayi
J
Ji
Chaoneng
C
Zhang
Xiaomeng
X
Gu
Shaohua
S
Xie
Yi
Y
Mao
Yumin
Y
D000595:Amino Acid Sequence; D017209:Apoptosis / Q000502:physiology*; D051017:Apoptosis Regulatory Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D001483:Base Sequence; D000072224:Bcl-2-Like Protein 11; D015153:Blotting, Western; D002460:Cell Line; D045304:Cytochromes c / Q000378:metabolism*; D005434:Flow Cytometry; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D008928:Mitochondria / Q000378:metabolism*; D008969:Molecular Sequence Data; D016366:Open Reading Frames / Q000235:genetics; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D016415:Sequence Alignment; D014162:Transfection
D051017:Apoptosis Regulatory Proteins; C000606775:BCL2L11 protein, human; D000072224:Bcl-2-Like Protein 11; D008565:Membrane Proteins; D020033:Protein Isoforms; D011518:Proto-Oncogene Proteins; D045304:Cytochromes c